HK1148883A - Discontinuous transmission signaling over an uplink control channel - Google Patents

Abstract

Systems and methodologies are described that facilitate signaling and detecting discontinuous transmission (DTX) in a wireless communication environment. A DTX indicator and Channel Quality Indicator (CQI) feedback can be multiplexed within a common uplink control channel subframe and transmitted to a base station when the access terminal is operating in DTX mode for an Acknowledgement Channel. Further, when operating in non-DTX mode, the access terminal can multiplex an ACK indicator or a NAK indicator with the CQI feedback within a common uplink control channel subframe, which can thereafter be transferred to the base station. Accordingly, the base station can detect DTX operation or non-DTX operation of the access terminal. For example, reference signal symbols can carry one of the DTX indicator, the ACK indicator, or the NAK indicator. Pursuant to another example, the CQI feedback and the DTX indicator can be combined and carried jointly by non-reference signal symbols.

Description

Discontinuous transmission signaling on uplink control channel

Related applicationCross reference of

The present application claims the benefit of united states provisional patent application No. 61/027,254 entitled "DTX coding IN LTE UPLINK CONTROL (DTXENCODING IN LTE UPLINK CONTROL)" filed on 8/2/2008 and united states provisional patent application No. 61/039,548 entitled "DTX coding IN LTE UPLINK CONTROL" filed on 26/3/2008. The foregoing application is incorporated by reference herein in its entirety.

Technical Field

The following description relates generally to wireless communications, and more particularly to signaling Discontinuous Transmission (DTX) via an uplink control channel in a wireless communication system.

Background

Wireless communication systems are widely deployed to provide various types of communication; for example, voice and/or data may be provided via these wireless communication systems. A typical wireless communication system or network may provide multiple users with access to one or more shared resources (e.g., bandwidth, transmit power, … …). For example, a system may use multiple access techniques such as frequency division multiple access (FDM), time division multiple access (TDM), code division multiple access (CDM), orthogonal frequency division multiple access (OFDM), and so on.

In general, a wireless multiple-access communication system may simultaneously support communication for multiple access terminals. Each access terminal may communicate with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to access terminals, and the reverse link (or uplink) refers to the communication link from access terminals to base stations. This communication link may be established via a single-input single-output, multiple-input single-output, or multiple-input multiple-output (MIMO) system.

MIMO systems typically use multiple (N)_TMultiple) transmitting antenna and multiple (N)_RMultiple) receive antennas for data transmission. From N_TA transmitting antenna and N_RMIMO channel formed by multiple receiving antennas can be decomposed into N_SA separate channel, which may be referred to as a spatial channel, where N_S≤{N_T，N_R}。N_SEach of the independent channels corresponds to a dimension. Furthermore, MIMO systems may provide improved performance (e.g., increased spectral efficiency, higher throughput, and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.

MIMO systems may support various duplexing techniques to divide forward and reverse link communications over a common physical medium. For example, a Frequency Division Duplex (FDD) system may utilize disparate frequency regions for forward link and reverse link communications. Further, in a Time Division Duplex (TDD) system, forward link communications and reverse link communications may use a common frequency region, such that the reciprocity principle allows estimation of the forward link channel from the reverse link channel.

Wireless communication systems often use one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast, and/or unicast services, wherein a data stream can be a stream of data that can be independently received by an access terminal. One, more than one, or all the data streams carried by the multiplexed stream may be received using an access terminal within the coverage area of such base station. Likewise, an access terminal can transmit data to the base station or another access terminal.

An access terminal may evaluate the quality of a wireless communication channel. For example, an access terminal may generate a metric of channel quality, such as a Channel Quality Indicator (CQI), which may be reported to a base station via an uplink channel. Further, information can be sent from a base station via a downlink control channel and/or a downlink data channel intended for the access terminal. The access terminal may acknowledge or deny detection of information communicated on the downlink data channel by sending an Acknowledgement Character (ACK) or a negative acknowledgement character (NAK) to the base station. Oftentimes, CQI information and ACK/NAK information may be multiplexed by an access terminal in a common uplink control channel subframe. However, conventional techniques (where CQI information is multiplexed with ACK/NAK information in the same uplink control channel subframe) typically do not allow an access terminal to distinguish between erroneously decoded information sent on a downlink data channel and information sent on a downlink control channel when reporting to a base station. Thus, the base station may not be able to identify whether the access terminal is unable to decode information communicated via the downlink data channel and/or information transmitted via the downlink control channel.

Disclosure of Invention

The following presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is intended to neither identify key or critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.

In accordance with one or more embodiments and corresponding disclosure thereof, various aspects are described in connection with facilitating signaling and detection of Discontinuous Transmission (DTX) in a wireless communication environment. When an access terminal operates in DTX mode for an Acknowledgement (ACK) channel, DTX indicator and Channel Quality Indicator (CQI) feedback can be multiplexed within a common uplink control channel subframe and transmitted to a base station. Further, when operating in a non-DTX mode, an access terminal can multiplex an ACK indicator or a NAK indicator with the CQI feedback within a common uplink control channel subframe, which can thereafter be communicated to the base station. Thus, the base station can detect DTX operation or non-DTX operation of the access terminal. According to an example, the reference signal symbols can carry one of a DTX indicator, an ACK indicator, or a NAK indicator. Pursuant to another example, CQI feedback and DTX indicators can be combined and carried jointly by non-reference signal symbols.

According to related aspects, a method that facilitates signaling Discontinuous Transmission (DTX) to a base station in a wireless communication environment is described herein. The method can include encoding Channel Quality Indicator (CQI) information and a DTX indicator within an uplink control channel subframe corresponding to a downlink control channel when it is determined that the downlink control channel has not been successfully decoded. Further, the method can include transmitting the encoded uplink control channel subframe to a base station.

Another aspect relates to a wireless communications apparatus. The wireless communications apparatus can include a memory that retains instructions related to: encoding Channel Quality Indicator (CQI) information and a Discontinuous Transmission (DTX) indicator within an uplink control channel subframe corresponding to a downlink control channel when it is determined that the downlink control channel has not been successfully decoded; encoding the CQI information and one of an Acknowledgement Character (ACK) indicator or a non-acknowledgement character (NAK) indicator within the uplink control channel subframe corresponding to the downlink control channel when it is determined that the downlink control channel has been successfully decoded; and transmitting the encoded uplink control channel subframe to a base station. Further, the wireless communications apparatus can include a processor, coupled to the memory, configured to execute the instructions retained in the memory.

Yet another aspect relates to a wireless communications apparatus that enables signaling Discontinuous Transmission (DTX) and Channel Quality Indicator (CQI) information to a base station in a wireless communication environment. The wireless communications apparatus can include means for encoding an uplink control channel subframe to include CQI information and at least one indicator that distinguishes between successful decoding of a downlink control channel and a downlink data channel, failed decoding of the downlink control channel, and failed decoding of the downlink data channel. Further, the wireless communications apparatus can include means for transmitting the uplink control channel subframe to a base station.

Yet another aspect relates to a computer program product, which may include a computer-readable medium. The computer-readable medium can comprise code for encoding an uplink control channel subframe to comprise Channel Quality Indicator (CQI) information and at least one indicator that distinguishes between successful decoding of a downlink control channel and a downlink data channel, failed decoding of the downlink control channel, and failed decoding of the downlink data channel. Further, the computer-readable medium can comprise code for communicating the uplink control channel subframe to a base station.

According to another aspect, an apparatus in a wireless communication system can comprise a processor, wherein the processor can be configured to determine whether to successfully decode a downlink control channel by recognizing whether an assignment corresponding to an uplink control channel sent via the downlink control channel is received and decoded. Further, the processor can be configured to encode Channel Quality Indicator (CQI) information and a DTX indicator within an uplink control channel subframe corresponding to the downlink control channel when it is determined that the downlink control channel has not been successfully decoded. Further, the processor can be configured to encode the CQI information and one of an Acknowledgement Character (ACK) indicator or a negative acknowledgement character (NAK) indicator within the uplink control channel subframe corresponding to the downlink control channel when it is determined that the downlink control channel has been successfully decoded. The processor can also be configured to transmit the encoded uplink control channel subframe to a base station.

According to other aspects, a method that facilitates detecting Discontinuous Transmission (DTX) in a wireless communication environment is described herein. The method can include receiving an uplink control channel subframe from an access terminal. Further, the method can include decoding the uplink control channel subframe to identify Channel Quality Indicator (CQI) feedback from the access terminal. Moreover, the method can include decoding the uplink control channel subframe to detect at least one indicator that distinguishes between successful decoding, downlink control channel decoding errors, and downlink data channel decoding errors encountered by the access terminal.

Yet another aspect relates to a wireless communications apparatus that can comprise a memory that retains instructions related to: obtaining an uplink control channel subframe from an access terminal; decoding the uplink control channel subframe to identify Channel Quality Indicator (CQI) feedback from the access terminal; and decoding the uplink control channel subframe to detect at least one indicator that distinguishes between successful decoding, downlink control channel decoding errors, and downlink data channel decoding errors encountered by the access terminal. Further, the wireless communications apparatus can include a processor coupled to the memory and configured to execute the instructions retained in the memory.

Another aspect relates to a wireless communications apparatus that enables detecting Discontinuous Transmission (DTX) signaled by an access terminal in a wireless communication environment. The wireless communications apparatus can include means for obtaining an uplink control channel subframe from an access terminal. Further, the wireless communications apparatus can include means for decoding the uplink control channel subframe to recognize Channel Quality Indicator (CQI) feedback and at least one indicator that distinguishes between successful decoding, downlink control channel false detection, and downlink data channel false detection encountered by the access terminal.

Yet another aspect relates to a computer program product, which may include a computer-readable medium. The computer-readable medium can comprise code for receiving an uplink control channel subframe from an access terminal. Moreover, the computer-readable medium can comprise code for decoding the uplink control channel subframe to recognize Channel Quality Indicator (CQI) feedback and at least one indicator that distinguishes between successful decoding, downlink control channel false detection, and downlink data channel false detection experienced by the access terminal.

According to another aspect, an apparatus in a wireless communication system can comprise a processor, wherein the processor can be configured to obtain an uplink control channel subframe from an access terminal. Further, the processor can be configured to decode the uplink control channel subframe to discover Channel Quality Indicator (CQI) feedback from the access terminal. Further, the processor can be configured to decode the uplink control channel subframe to recognize at least one indicator that distinguishes between successful decoding, downlink control channel decoding errors, and downlink data channel decoding errors encountered by the access terminal.

To the accomplishment of the foregoing and related ends, the one or more embodiments comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth herein detail certain illustrative aspects of the one or more embodiments. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments may be employed and the described embodiments are intended to include all such aspects and their equivalents.

Drawings

Fig. 1 is an illustration of a wireless communication system in accordance with various aspects set forth herein.

Fig. 2 is an illustration of an example system that employs DTX signaling in a wireless communication environment.

Fig. 3 is an illustration of an example system that utilizes a reference signal to signal DTX in a wireless communication environment.

Fig. 4 is an illustration of an example system that encodes DTX information with CQI information in a wireless communication environment.

Fig. 5 is an illustration of an example PUCCH subframe that can be employed in connection with DTX signaling within a wireless communication environment.

Fig. 6 is an illustration of an example methodology that facilitates signaling Discontinuous Transmission (DTX) to a base station in a wireless communication environment.

Fig. 7 is an illustration of an example methodology that facilitates detecting Discontinuous Transmission (DTX) in a wireless communication environment.

Fig. 8 is an illustration of an example access terminal sending a DTX indicator to a base station in a wireless communication system.

Fig. 9 is an illustration of an example system that detects DTX uplink transmissions in a wireless communication environment.

Fig. 10 is an illustration of an example wireless network environment that can be employed in conjunction with the various systems and methods described herein.

Fig. 11 is an illustration of an example system that enables signaling Discontinuous Transmission (DTX) and Channel Quality Indicator (CQI) information to a base station in a wireless communication environment.

Fig. 12 is an illustration of an example system that enables detecting Discontinuous Transmission (DTX) signaled by an access terminal in a wireless communication environment.

Detailed Description

Various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

As used in this application, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity (either hardware, firmware, a combination of hardware and software, or software in execution). For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, an application running on a computing device and the computing device can be a component. One or more components may reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal).

The techniques described herein may be used for various wireless communication systems such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and other systems. The terms "system" and "network" are often used interchangeably. A CDMA system may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes wideband CDMA (W-CDMA) and other variants of CDMA. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA system may implement a radio technology such as global system for mobile communications (GSM). The OFDMA system may implement radio technologies such as evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is an upcoming release of UMTS that uses E-UTRA, which uses OFDMA on the downlink and SC-FDMA on the uplink.

Single carrier frequency division multiple access (SC-FDMA) utilizes single carrier modulation and frequency domain equalization. SC-FDMA has performance similar to that of OFDMA systems and has an overall complexity substantially the same as that of OFDMA systems. The SC-FDMA signal has a lower peak-to-average power ratio (PAPR) due to its inherent single carrier structure. SC-FDMA may be used, for example, in uplink communications, where a lower PAPR greatly benefits access terminals in terms of transmit power efficiency. Thus, SC-FDMA may be implemented as an uplink multiple access scheme in 3GPP Long Term Evolution (LTE) or evolved UTRA.

Moreover, various embodiments are described herein in connection with an access terminal. An access terminal can also be called a system, subscriber unit, subscriber station, mobile (mobile), remote station, remote terminal, mobile device, user terminal, wireless communication device, user agent, user device, or User Equipment (UE). An access terminal may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having wireless connection capability, a computing device, or other processing device connected to a wireless modem. Moreover, various embodiments are described herein in connection with a base station. A base station may be utilized for communicating with access terminal(s) and may also be referred to as an access point, node B, evolved node B (enodeb), or some other terminology.

Various aspects or features described herein may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card, stick, key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

Referring now to fig. 1, a wireless communication system 100 is illustrated in accordance with various embodiments presented herein. System 100 includes a base station 102 that can include multiple antenna groups. For example, one antenna group may include antennas 104 and 106, another group may include antennas 108 and 110, and an additional group may include antennas 112 and 114. Two antennas are illustrated for each antenna group; however, more or fewer antennas may be used for each group. As will be appreciated by those skilled in the art, base station 102 can additionally comprise a transmitter chain and a receiver chain, each of which in turn can comprise a plurality of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.).

Base station 102 may communicate with one or more access terminals, such as access terminal 116 and access terminal 122; however, it is to be appreciated that base station 102 can communicate with substantially any number of access terminals similar to access terminals 116 and 122. Access terminals 116 and 122 can be, for example, cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating over wireless communication system 100. As depicted, access terminal 116 is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to access terminal 116 over forward link 118 and receive information from access terminal 116 over reverse link 120. Further, access terminal 122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to access terminal 122 over forward link 124 and receive information from access terminal 122 over reverse link 126. In a Frequency Division Duplex (FDD) system, forward link 118 can utilize a different frequency band than that used by reverse link 120, and forward link 124 can employ a different frequency band than that employed by reverse link 126, for example. Further, in a Time Division Duplex (TDD) system, forward link 118 and reverse link 120 can utilize a common frequency band and forward link 124 and reverse link 126 can utilize a common frequency band.

Each group of antennas and/or the area in which they are designated to communicate can be referred to as a sector of base station 102. For example, antenna groups can be designed to communicate to access terminals in a sector of the areas covered by base station 102. In communication over forward links 118 and 124, the transmitting antennas of base station 102 can utilize beamforming to improve signal-to-noise ratio of forward links 118 and 124 for access terminals 116 and 122. Also, when base station 102 utilizes beamforming to transmit to access terminals 116 and 122 scattered randomly through an associated coverage, access terminals in neighboring cells can experience less interference as compared to a base station transmitting via a single antenna to all its access terminals.

The system 100 enables the use of an enhanced coding scheme that allows an access terminal 116, 122 to signal downlink control channel mis-decoding (e.g., mis-decoding of a Physical Downlink Control Channel (PDCCH), … …) via an uplink control channel (e.g., a Physical Uplink Control Channel (PUCCH), … …) using Channel Quality Indicator (CQI) information and Acknowledgement Character (ACK)/non-acknowledgement character (NAK) information. In contrast, conventional coding schemes (e.g., … … for PUCCH) typically cannot allow an access terminal 116, 122 to signal a downlink control channel (e.g., PDCCH, … …) false detection when CQI information and ACK/NAK information are multiplexed in the same PUCCH subframe. Thus, for the case of the conventional scheme, the base station 102 may not be able to detect whether an access terminal (e.g., access terminal 116, 122, … …) successfully decodes the PDCCH.

System 100 may support Discontinuous Transmission (DTX) signaling on an uplink control channel (e.g., PUCCH, … …). DTX signaling may provide the ability to distinguish downlink control channel (e.g., PDCCH, … …) decoding errors from downlink data channel (e.g., Physical Downlink Shared Channel (PDSCH), … …) decoding errors. DTX information may be multiplexed with CQI information and/or ACK/NAK information within a common uplink control channel (e.g., PUCCH, … …) subframe. In contrast, the conventional framework for CQI and ACK/NAK multiplexing for normal cyclic prefix lengths may not be able to support DTX signaling.

DTX signaling on the uplink control channel (e.g., PUCCH, … …) enables the base station 102 to detect a condition in which the downlink control channel (e.g., PDCCH, … …) is not decoded by a particular access terminal (e.g., access terminal 116, access terminal 122, … …). Base station 102 can detect whether the particular access terminal is operating in DTX mode or non-DTX mode based on DTX signaling (e.g., for an Acknowledgement (ACK) channel, … …).

With regard to DTX detection, base station 102 may preferably select a Redundancy Version (RV) for retransmission as part of a hybrid automatic repeat request (HARQ) technique. For example, upon determining that a given access terminal (e.g., access terminal 116, access terminal 122, … …) is operating in DTX mode (e.g., based on the received DTX indicator, … …), the base station 102 may recognize that the downlink control channel (e.g., PDCCH, … …) was not decoded by the given access terminal. According to this example, as a result of determining that the downlink control channel is not decoded, the base station 102 may further identify that the given access terminal lacks demodulated downlink data channel (e.g., PDSCH, … …) information stored in an associated HARQ buffer, and thus, may select RV 0 for retransmission as part of the HARQ technique. By way of yet another example, upon recognizing that an access terminal (e.g., access terminal 116, access terminal 122, … …) is operating in a non-DTX mode (with a NAK received from the access terminal), the base station 102 can identify that a downlink control channel (e.g., PDCCH, … …) is decoded by the access terminal and that a downlink data channel (e.g., PDSCH, … …) cannot be decoded by the access terminal. Pursuant to this example, base station 102 can determine that an access terminal has a received version of RV 0 stored in an associated HARQ buffer; based on this, the base station 102 may select a redundancy version other than RV-0 (e.g., RV-1, … …) to retransmit to an access terminal as part of the HARQ technique.

Further, the base station 102 can utilize DTX detection to estimate the downlink control channel (e.g., PDCCH, … …) decoding error rate for each access terminal 116, 122. Based on the estimated decoding error rate, the base station 102 can individually optimize allocation of resources (e.g., number of Control Channel Elements (CCEs), transmit power, … …) for downlink control channel (e.g., PDCCH, … …) transmission for each access terminal 116, 122. By way of further illustration, base station 102 can utilize the estimated decoding error rate to optimize resource allocation for a set of access terminals.

Referring to fig. 2, illustrated is a system 200 that employs DTX signaling in a wireless communication environment. System 200 includes an access terminal 202 that can transmit and/or receive information, signals, data, instructions, commands, bits, symbols, and the like, from access terminal 202. Access terminal 202 can communicate with base station 204 via a forward link and/or a reverse link. Base station 204 can transmit and/or receive information, signals, data, instructions, commands, bits, symbols, and the like. Moreover, although not shown, it is contemplated that any number of access terminals similar to access terminal 202 can be included in system 200 and/or any number of base stations similar to base station 204 can be included in system 200. According to an illustration, system 200 can be a Long Term Evolution (LTE) based system; however, claimed subject matter is not so limited.

Access terminal 202 can include a downlink channel decoder 206 that decodes information, signals, data, instructions, commands, bits, symbols, and the like obtained via a downlink channel. For example, the downlink channel decoder 206 may decode a downlink control channel (e.g., PDCCH, … …), a downlink data channel (e.g., PDSCH, … …), and so on. By way of illustration, downlink decoder 206 can decode an assignment conveyed via PDCCH that schedules uplink channel resources to be utilized by access terminal 202 (e.g., time and frequency for sending a transmission via the uplink channel, PUCCH resources, … …); however, claimed subject matter is not so limited. Pursuant to another illustration, the downlink channel decoder 206 can decode, demodulate, etc., data obtained via the PDSCH.

Access terminal 202 can further comprise a CQI report generator 208 that generates CQI reports that provide information related to channel quality. CQI report generator 208 may generate CQI reports at substantially any periodicity. Alternatively, the CQI report generator 208 may generate CQI reports non-periodically.

Further, access terminal 202 can comprise an encoder 210 that encodes signals for transmission. For example, encoder 210 may multiplex various signals, and the multiplexed signals may thereafter be transmitted by access terminal 202 (e.g., via a transmitter (not shown), antenna (not shown), … …) to base station 204. For example, the multiplexed signal may be sent on an uplink control channel (e.g., PUCCH, … …) to base station 204; however, claimed subject matter is not so limited.

Encoder 210 may further include a CQI signaling device 212, an ACK/NAK signaling device 214, and a DTX signaling device 216. CQI signaling device 212 may obtain CQI reports from CQI report generator 208 and incorporate the CQI reports into the encoded signal sent on the uplink. Further, the ACK/NAK signal device 214 may insert an ACK indicator into the encoded signal when the downlink channel decoder 206 successfully demodulates information sent on a downlink data channel (e.g., PDSCH, … …), or a NAK indicator into the encoded signal when the downlink channel decoder 206 cannot successfully demodulate information sent on a downlink data channel (e.g., PDSCH, … …). Further, DTX signaling device 216 may incorporate a DTX indicator into the encoded signal when downlink channel decoder 206 is unable to successfully decode an assignment sent on a downlink control channel (e.g., PDCCH, … …). Accordingly, DTX signaling device 216 may inform base station 204 by including a DTX indicator in the encoded signal sent on the uplink (e.g., via PUCCH, … …): access terminal 202 operates in DTX mode (e.g., in conjunction with an Acknowledgement (ACK) channel, … …). By utilizing CQI signaling 212, ACK/NAK signaling 214, and DTX signaling 216, encoder 210 may multiplex the CQI information, ACK/NAK information, and/or DTX information into a common uplink control channel (e.g., PUCCH, … …) subframe.

Base station 204 may further include a scheduler 218 and an uplink channel decoder 220. Scheduler 218 can assign resources (e.g., uplink resources, downlink resources, … …) for use by access terminal 202. For example, scheduler 218 can allocate uplink resources to access terminal 202 and generate an assignment that can be communicated to access terminal 202 to indicate such allocation of uplink resources. By way of further illustration, assignments generated by scheduler 218 can be communicated to access terminal 202 via a downlink control channel (e.g., PDCCH, … …); however, claimed subject matter is not so limited.

Further, uplink channel decoder 220 may decode signals received by base station 204 via the uplink. For example, the uplink channel decoder 220 may demultiplex a plurality of signals obtained via the uplink (e.g., a plurality of symbols received within a common subframe, … …). According to yet another example, the uplink channel decoder 220 can demodulate signals received on an uplink control channel (e.g., PUCCH, … …).

The uplink channel decoder 220 may further include a CQI detector 222, an ACK/NAK evaluator 224, and a DTX identifier 226. CQI detector 222 can recognize CQI information received from access terminal 202 as part of an uplink transmission. Further, ACK/NAK evaluator 224 may identify whether an ACK indicator or a NAK indicator is included in the uplink transmission. The ACK indicator or NAK indicator may be sent by the access terminal 202 according to whether the access terminal 202 successfully decoded (e.g., by the downlink channel decoder 206, … …) a downlink transmission sent by the base station 204 via a downlink data channel (e.g., PDSCH, … …). In addition, DTX identifier 226 can identify when the uplink transmission includes a DTX indicator to distinguish whether the uplink transmission is a DTX transmission sent by access terminal 202. Accordingly, DTX identifier 226 can detect when access terminal 202 is operating in DTX mode.

According to an illustration, DTX signaling may occur naturally when the access terminal conventionally transmits PUCCH format 0 or 1. According to this illustration, PUCCH DTX can result when the access terminal misses the PDCCH. Further, this may be detectable by the base station (e.g., … … if the base station uses a tri-state receiver). However, the foregoing description cannot consider the case where CQI information is multiplexed with an ACK indicator or a NAK indicator.

When the ACK indicator or the NAK indicator is multiplexed together with the CQI information on the PUCCH, the aforementioned DTX signaling does not occur naturally because the CQI information will be transmitted regardless of the PDCCH decoding result. Furthermore, conventional schemes typically encode the CQI information plus NAK indicator as the same transmit waveform as the CQI information alone (e.g., independent CQI information without ACK/NAK multiplexing, … …). Thus, these conventional schemes may not enable the base station to detect DTX operation of the access terminal.

A commonly used scheme may modulate PUCCH Reference Signal (RS) symbols with ACK or NAK information. For example, in each slot, two reference signal symbols may be transmitted to provide a phase reference for PUCCH decoding with a normal cyclic prefix length. In the case of CQI-only transmission (e.g., without an ACK or NAK, … …, which may occur when the access terminal is in DTX mode), both reference signal symbols within a slot may be set to '1'. Further, in the case of transmission of CQI plus ACK or NAK, a first of two reference signal symbols within a slot may be set to '1' while a second reference signal symbol within the slot is set to '1' or '-1' to signal ACK or NAK in a Single Input Multiple Output (SIMO) case, or the second reference signal symbol may be set to one of four Quadrature Phase Shift Keying (QPSK) symbols to signal NAK/NAK, ACK/NAK, NAK/ACK or ACK/ACK for two Multiple Input Multiple Output (MIMO) streams. For example, the mapping for the MIMO case may be as follows: NAK/NAK may be mapped to '1', ACK/NAK may be mapped to 'j', NAK/ACK may be mapped to '-j', and ACK/ACK may be mapped to '-1'. However, it should be appreciated that other mappings and/or other constellation point selections may alternatively be utilized. Further, for example, the transmitted symbols may be rotated 45 degrees to match a conventional QPSK constellation; however, claimed subject matter is not so limited.

System 200 modifies the aforementioned settings such that access terminal 202 can perform DTX signaling and base station 204 can perform DTX detection. When the PUCCH carries CQI multiplexed with ACK or NAK information in the same subframe for normal cyclic prefix length, access terminal 202 can signal missed PDCCH conditions on the uplink PUCCH. Access terminal 202 can employ various signaling options for downlink SIMO operations and/or downlink MIMO operations.

By way of further example, uplink channel decoder 220 can adjust PUCCH decoding when base station 204 has not scheduled (e.g., with scheduler 218, … …) access terminal 202 to send a transmission on the uplink but received an uplink transmission (e.g., PUCCH subframe, … …), assuming access terminal 202 is in a DTX state. Thus, assuming DTX is signaled by access terminal 202, uplink channel decoder 220 (e.g., DTX identifier 226, … …) can decode the obtained PUCCH subframe. Thus, the decoding performance in this case may be substantially similar to that of the conventional scheme, and thus, the addition of DTX signaling may not significantly adversely affect the performance of the CQI format only.

Referring now to fig. 3, illustrated is a system 300 that utilizes a reference signal to signal DTX in a wireless communication environment. System 300 includes an access terminal 202 that can further include an encoder 210, and a base station 204 that can further include an uplink channel decoder 220. The encoder 210 may include a CQI signaling device 212 that encodes CQI information (e.g., CQI information generated by the CQI report generator 208 of fig. 2, … …) for transmission to the base station 204.

Encoder 210 may also include a reference signal generator 302, which may further include, for example, an ACK/NAK signal device 214 and a DTX signal device 216. Pursuant to this example, reference signal generator 302 can utilize ACK/NAK signaling device 214 and DTX signaling device 216 to encode an ACK indicator, NAK indicator, and/or DTX indicator with reference signal symbols that can be transmitted on an uplink control channel (e.g., PUCCH, … …). Thus, according to the depicted example, two symbols (e.g., reference signal, … …) within a slot may be encoded to signal an ACK, NAK, or DTX to base station 204, while the remainder of the symbols (e.g., five remaining symbols, … …) in the slot may be encoded with CQI information by CQI signaling device 212.

The uplink channel decoder 220 may include a CQI detector 222 and a reference signal analyzer 304. The reference signal analyzer 304 can further include an ACK/NAK evaluator 224 and a DTX identifier 226, and can evaluate received reference signal symbols to detect whether an ACK, NAK, or DTX has been signaled by the access terminal 202 (e.g., reference signal generator 302, … …). Thus, as illustrated, reference signal symbols (e.g., two symbols, … …) within a slot can be decoded by reference signal analyzer 304 (e.g., utilizing ACK/NAK estimator 224 and DTX identifier 226, … …) to detect an ACK indicator, NAK indicator, or DTX indicator, while the remainder of the symbols in the slot can be evaluated by CQI detector 222 to determine CQI feedback provided by access terminal 202.

According to an illustration, system 300 can be employed with downlink SIMO. The reference signal generator 302 may set the first reference signal symbol to '1' (or any other preset value). Further, reference signal generator 302 (e.g., based on whether ACK, NAK, or DTX is provided via ACK/NAK signaling 214 and DTX signaling 216, … …) may set the second reference signal symbol to one of three possible QPSK symbols (e.g., a three-element subset of a four-element QPSK constellation, … …). By way of example, reference signal generator 302 may use the following mapping for the second reference signal: NAK may be mapped to '1', ACK may be mapped to '-1', and DTX may be mapped to 'j'. According to another example, for the second reference signal, DTX may be mapped to '1' if no DTX indicator is transmitted. However, it is contemplated that any mapping is intended to be within the scope of the claims appended hereto. Further, for example, when utilizing such a coding scheme, uplink channel decoder 220 may evaluate three possible hypotheses for operating in conjunction with SIMO.

When reference signal analyzer 304 independently decodes ACK, NAK, and DTX based on modulated reference signal symbols, the above mapping can minimize decoding errors if NAK is mistaken for ACK (or ACK is mistaken for NAK) for the QPSK constellation. Other mappings may alternatively be used in conjunction with DTX signaling, such as 3-PSK constellation points, conventional QPSK constellation points (e.g., rotated 45 degrees from the above constellation, { [ (1, j), (-1, j), (1, -j), (-1, -j) ]/sqrt (2) }, … …), etc.

Moreover, the foregoing illustrates an example of modeling DTX with ACK/NAK modulated reference signal symbols (e.g., pilot, … …). According to another example, QPSK modulation may be used for two reference signal symbols (e.g., two pilots, … …) communicated via the uplink in a time slot, rather than setting a first reference signal symbol to '1' (or any other predetermined value) and modulating a second reference signal symbol to encode an ACK, NAK, or DTX. For example, the first reference signal symbol may be set to one of '1', '-1', 'j' or '-j' and the second reference signal symbol may be set to one of '1', '-1', 'j' or '-j', which results in 16 different combinations. For DTX and ACK/NAK signaling, three of the 16 possible combinations may be selected to maximize the distance between ACK, NAK, and DTX, thereby minimizing the impact of channel phase variations on the detectability achieved by reference signal analyzer 304.

For example, in the case of downlink MIMO utilizing two bits to indicate ACK and/or NAK, DTX signaling may be omitted in connection with system 300. The omission of DTX signaling may be substantially similar to sending a '1' on the first reference signal symbols and a '1' on the second reference signal symbols when operating in DTX mode (e.g., which may be substantially similar to indicating NAK/NAK, … …, for two MIMO streams). According to this example, access terminal 202 can operate with higher geometries on average when in MIMO mode; thus, PDCCH decoding error rate may be reduced with on average less downlink power overhead than using SIMO. Thus, the lack of DTX signaling may have less impact. It should be appreciated, however, that claimed subject matter is not limited to the foregoing examples.

Turning to fig. 4, illustrated is a system 400 that encodes DTX information with CQI information in a wireless communication environment. System 400 includes an access terminal 202 and a base station 204. Access terminal 202 includes an encoder 210 that further includes a CQI signaling device 212 and a reference signal generator 302. The CQI signaling device 212 may further include a DTX signaling device 216 and the reference signal generator 302 may further include an ACK/NAK signaling device 214. Further, base station 204 may include an uplink channel decoder 220. The uplink channel decoder 220 includes a CQI detector 222, which may further include a DTX identifier 226, and a reference signal analyzer 304, which may further include an ACK/NAK evaluator 224.

By way of example, the CQI information and DTX information may be encoded together by CQI signaling device 212 and DTX signaling device 216. For example, DTX signaling device 216 may add transmission status bits in addition to the CQI information bits provided by CQI signaling device 212. The value of the additional transmission status bit may indicate whether access terminal 202 is in a DTX state. Further, the CQI information bits and the transmission status bits may be jointly encoded. For example, reed-muller (RM) encoding (e.g., RM or RM with computer generated extensions, … …) may be used, and the additional transmit state bits may be switched between linearly adding or not adding particular RM (or computer generated) basis vectors.

Further, CQI detector 222 and DTX identifier 226 can evaluate, decode, demodulate, etc., the combined encoded information received from access terminal 202 to extract CQI information and DTX information included therein. For example, DTX identifier 226 may determine the value of the additional transmission status bit to recognize whether access terminal 202 is operating in a DTX state (e.g., recognize whether access terminal 202 successfully decoded PDCCH, … …).

Further, the reference signal symbols generated by reference signal generator 302 may be set by ACK/NAK signaling device 214 to signal, for example, an ACK or NAK. Accordingly, reference signal analyzer 304 (e.g., and/or ACK/NAK assessors 224, … …) can evaluate received reference signal symbols to identify an ACK or NAK sent by access terminal 202.

It is to be appreciated that system 400 can be employed in connection with downlink SIMO operations and/or downlink MIMO operations. When base station 204 schedules a downlink transmission for access terminal 202 corresponding to a particular received PUCCH subframe, uplink channel decoder 220 can typically evaluate three possible hypotheses for downlink SIMO operating scenarios and five possible hypotheses for downlink MIMO operating scenarios. Further, base station 204 can use a Maximum Likelihood (ML) receiver to jointly decode CQI and ACK/NAK, and thus, the selection of an hypothesis can be made by selecting the correct set of combined hypotheses. As an example, in the SIMO case, the combination of DTX encoded with CQI and ACK encoded with reference signal symbols may be excluded from the set of ML hypotheses. Similarly, for the MIMO case, any combination of DTX encoded in CQI along with any other than NAK/NAK encoded in reference signal symbols may be excluded from the set of ML hypotheses. Based on the above considerations, a modest overall impact of DTX signaling on PUCCH decoding performance may result.

Referring to fig. 5, illustrated is an example PUCCH subframe 500 that can be utilized in connection with DTX signaling within a wireless communication environment. PUCCH subframe 500 includes two consecutive slots, slot 502 and slot 504 (e.g., slot 502 and slot 504 may each be 0.5ms, … …). Further, as depicted, each time slot 502-504 may include seven symbols (e.g., having a normal cyclic prefix length, … …). Within a given slot, two symbols may be reference signal symbols and five symbols may be CQI symbols. Thus, in slot 502, symbols 1 and 5 may be reference signal symbols and symbols 0, 2, 3, 4, and 6 may be CQI symbols. Similarly, in slot 504, symbols 8 and 12 may be reference signal symbols and symbols 7, 9, 10, 11, and 13 may be CQI symbols. According to the example described above, DTX may be signaled based on the selection of reference signal symbols (e.g., along with ACK/NAK information, … …). According to another example described herein, DTX can be signaled based on additional transmit status bits that can be encoded within the CQI symbol. It should be appreciated, however, that claimed subject matter is not limited to the foregoing.

Referring to fig. 6-7, methodologies relating to signaling and detecting DTX in a wireless communication environment are illustrated. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more embodiments.

Referring to fig. 6, a methodology 600 that facilitates signaling Discontinuous Transmission (DTX) to a base station in a wireless communication environment is illustrated. At 602, a determination can be effectuated as to whether the downlink control channel was successfully decoded. For example, the downlink control channel may be a Physical Downlink Control Channel (PDCCH). Further, the downlink control channel can provide for assignment of resources (e.g., time and frequency, … …) for use in connection with uplink transmissions (e.g., transmissions on a corresponding uplink control channel, … …). Thus, the determination performed at 602 can be used to recognize whether an assignment sent over the downlink control channel was received and successfully decoded.

When it is determined at 602 that the downlink control channel has not been successfully decoded (e.g., the assignment has not been received and/or decoded, … …), method 600 may continue to 604. At 604, Channel Quality Indicator (CQI) information and a DTX indicator may be encoded within an uplink control channel subframe corresponding to the downlink control channel. The uplink control channel subframe may be a Physical Uplink Control Channel (PUCCH) subframe. According to an example, a first set of symbols (e.g., reference signal symbols, two symbols, … …) within a slot can be encoded to include the DTX indicator, and a second set of symbols (e.g., non-reference signal symbols, five symbols, remaining symbols, … …) within the slot can be encoded to include the CQI information, wherein symbols in the first set can be mutually exclusive from symbols in the second set. By way of yet another example, bits set to a value corresponding to the DTX indicator can be added to bits representing the CQI information, and a common set of symbols can be encoded to collectively comprise a combination of the DTX indicator and the CQI information. At 606, the encoded uplink control channel subframe can be transmitted to a base station. Accordingly, DTX may be signaled to the base station.

When it is determined at 602 that the downlink control channel has been successfully decoded (e.g., the assignment has been received and decoded, … …), method 600 may continue to 608. At 608, one of CQI information and an Acknowledgement Character (ACK) indicator or a non-acknowledgement character (NAK) indicator may be encoded within the uplink control channel subframe corresponding to the downlink control channel. For example, a first set of symbols (e.g., reference signal symbols, two symbols, … …) within a slot may be encoded to include the ACK indicator or the NAK indicator, and a second set of symbols (e.g., non-reference signal symbols, five symbols, remaining symbols, … …) within the slot may be encoded to include the CQI information, wherein symbols in the first set may be mutually exclusive from symbols in the second set. According to yet another example, bits set to a value corresponding to non-DTX operation may be added to bits representing the CQI information, and a set of symbols may be encoded to collectively comprise a combination of these bits. At 610, the encoded uplink control channel subframe can be transmitted to the base station.

According to an example encoding scheme, a first set of symbols (e.g., reference signal symbols, two symbols, … …) within the slot may be encoded to include the DTX indicator when the downlink control channel is not successfully decoded (e.g., … …, as determined at 602), and the first set of symbols may be encoded to include one of the ACK indicator or the NAK indicator when the downlink control channel is successfully decoded. For example, symbols in the first set may use a first mapping when incorporating the DTX indicator, a second mapping when incorporating the ACK indicator, and a third mapping when incorporating the NAK indicator. As an illustration, a first symbol (e.g., a first reference signal symbol, … …) in the first set can be set to '1' and a second symbol (e.g., a second reference signal symbol, … …) in the first set can be set to one of a plurality of possible values (e.g., to 'j' for DTX, '1' for ACK, and 1 'for NAK,' 1 'for DTX,' 1 'for ACK, and 1' for NAK, … …); it should be understood, however, that claimed subject matter is not limited to the foregoing description, as it is contemplated that any mapping is intended to be within the scope of the claims appended hereto. Further, as part of this example encoding scheme, a second set of symbols (e.g., non-reference signal symbols, five symbols, remaining symbols, … …) within the time slot may be encoded to include the CQI information, wherein symbols in the first set may be mutually exclusive from symbols in the second set. Further, this example coding scheme may be utilized in connection with downlink Single Input Multiple Output (SIMO) operations. According to another illustration, a first symbol (e.g., a first reference signal symbol, … …) in the first set can be set to '1' and a second symbol (e.g., a second reference signal symbol, … …) in the first set can be set to '1' when in a DTX mode operating in conjunction with downlink multiple-input multiple-output (MIMO).

With another example coding scheme, transmit status bits may be added to the CQI information bits. The value of the transmission status bit may be set based on whether DTX mode or non-DTX mode is used (e.g., whether the downlink control channel was successfully decoded to produce a corresponding assignment of uplink control channel resources, … …). Further, the transmit state bits may switch between linearly adding or not adding particular reed-muller (RM) basis vectors based on DTX operation or non-DTX operation. For example, this example coding scheme may be used in connection with downlink SIMO operations and/or downlink multiple-input multiple-output (MIMO) operations.

Turning now to fig. 7, illustrated is a methodology 700 that facilitates detecting Discontinuous Transmission (DTX) in a wireless communication environment. At 702, an uplink control channel subframe can be received from an access terminal. The uplink control channel subframe may be a Physical Uplink Control Channel (PUCCH) subframe. According to an illustration, the uplink control channel subframe may not correspond to an assignment sent to the access terminal via a downlink transmission, and thus, a DTX state can be assumed for the access terminal. By way of another example, the uplink control channel subframe can correspond to an assignment communicated to the access terminal via a downlink transmission, and thus, the uplink control channel subframe can be decoded to distinguish, by the access terminal, DTX operation from non-DTX operation.

At 704, the uplink control channel subframe can be decoded to identify CQI feedback from the access terminal. At 706, the uplink control channel subframe can be decoded to detect at least one indicator that distinguishes between successful decoding, downlink control channel decoding errors, and downlink data channel decoding errors encountered by the access terminal. The at least one indicator may be one or more of a DTX indicator, an Acknowledgement Character (ACK) indicator, or a negative acknowledgement resource (NAK) indicator. According to an illustration, the CQI feedback and the at least one indicator can be jointly decoded, separately decoded, a combination of both, and/or the like. By way of example, the at least one indicator may be detected from a first set of symbols (e.g., two reference signal symbols, … …) within a slot, and the CQI feedback may be identified from a second set of symbols (e.g., non-reference signal symbols, five symbols, remaining symbols, … …) within the slot. Pursuant to yet another example, the at least one indicator can be detected based at least in part on a value of a transmission status bit added to CQI information bits carried by a set of symbols within the uplink control channel subframe.

It will be appreciated that, in accordance with one or more aspects described herein, inferences can be made regarding signaling and/or detecting DTX in a wireless communication environment. As used herein, the term to "infer" or "inference" refers generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The inference can be probabilistic-that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. Whether or not the events are correlated in close temporal proximity, and whether the events and data come from one or several event and data sources, this inference results in the construction of new events or actions from observed events and/or stored sets of event data.

According to an example, one or more methods presented above can include making inferences pertaining to selecting a most likely combination of CQI information and ACK/NAK/DTX indicators sent by an access terminal. By way of further illustration, inferences can be made regarding determining a mapping to be used in connection with DTX signaling. It will be appreciated that the foregoing examples are illustrative in nature and are not intended to limit the number of inferences that can be made or the manner in which such inferences are made in conjunction with the various embodiments and/or methods described herein.

Fig. 8 is an illustration of an access terminal 800 that transmits a DTX indicator to a base station in a wireless communication system. Access terminal 800 comprises a receiver 802 that receives a signal from, for instance, a receive antenna (not shown), and performs typical actions thereon (e.g., filters, amplifies, downconverts, etc.) the received signal and digitizes the conditioned signal to obtain samples. Receiver 802 can be, for example, an MMSE receiver, and can comprise a demodulator 804 that can demodulate received symbols and provide them to a processor 806 for channel estimation. Processor 806 can be a processor dedicated to analyzing information received by receiver 802 and/or generating information for transmission by a transmitter 816, a processor that controls one or more components of access terminal 800, and/or a processor that both analyzes information received by receiver 802, generates information for transmission by transmitter 816, and controls one or more components of access terminal 800.

Access terminal 800 can additionally comprise memory 808, memory 808 operatively coupled to processor 806 and that may store data to be transmitted, received data, and any other suitable information related to performing the various actions and functions set forth herein. For example, memory 808 can store protocols and/or algorithms associated with signaling CQI information along with one or more of a DTX indicator, an ACK indicator, or a NAK indicator within a common PUCCH subframe. Further, memory 808 can store protocols and/or algorithms for generating CQI information.

It will be appreciated that the data store (e.g., memory 808) described herein can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. By way of illustration, and not limitation, nonvolatile memory can include Read Only Memory (ROM), programmable ROM (prom), electrically programmable ROM (eprom), electrically erasable prom (eeprom), or flash memory. Volatile memory can include Random Access Memory (RAM), which acts as external cache memory. By way of illustration and not limitation, RAM may be used in many forms, such as Synchronous RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 808 of the subject systems and methods is intended to comprise, without being limited to, these and any other suitable types of memory.

Processor 806 can be operatively coupled to CQI signaling device 810 and/or reference signal generator 812. CQI signaling device 810 may be substantially similar to CQI signaling device 212 of fig. 2 and/or reference signal generator 812 may be substantially similar to reference signal generator 302 of fig. 3. CQI signaling device 810 may generate CQI information for inclusion in PUCCH subframes. For example, CQI signaling device 810 can cause CQI information to be included within non-reference signal symbols in a slot. In addition, the reference signal generator 812 may generate reference signal symbols of the same slot. Moreover, it is to be appreciated that access terminal 800 can operate in a DTX or non-DTX mode. According to an example, reference signal generator 812 can incorporate a DTX indicator into the generated reference signal symbols when in DTX mode. According to this example, reference signal generator 812 can incorporate an ACK indicator or a NAK indicator into the generated reference signal symbols when in non-DTX mode. By way of another example, CQI signaling device 810 can set the value of the additional bits added to the CQI information bits depending on whether access terminal 800 is in DTX mode or non-DTX mode. Although not shown, it is to be appreciated that access terminal 800 can include an ACK/NAK signaling device that can be substantially similar to ACK/NAK signaling device 214 of fig. 2, and/or a DTX signaling device that can be substantially similar to DTX signaling device 216 of fig. 2. Access terminal 800 still further comprises a modulator 814 and a transmitter 816 that transmits data, signals, etc. to base station. Although depicted as being separate from the processor 806, it is to be appreciated that the CQI signaling device 810, the reference signal generator 812, and/or the modulator 814 can be part of the processor 806 or many processors (not shown).

Fig. 9 is an illustration of a system 900 that detects DTX uplink transmissions in a wireless communication environment. System 900 includes a base station 902 (e.g., access point, … …), base station 902 having: a receiver 910 that receives signals from one or more access terminals 904 via a plurality of receive antennas 906; and a transmitter 924 that transmits to the one or more access terminals 904 via transmit antenna 908. Receiver 910 can receive information from receive antennas 906 and is operatively associated with a demodulator 912 that demodulates received information. Demodulated symbols are analyzed by a processor 914, which processor 914 can be similar to that described above with respect to fig. 8, and which is coupled to a memory 916, which memory 916 stores data to be transmitted to or received from access terminal 904 and/or any other suitable information related to performing the various acts and functions set forth herein. Processor 914 is further coupled to a reference signal analyzer 918, which reference signal analyzer 918 evaluates reference signal symbols in the PUCCH subframe to detect an indicator incorporated therein. Further, base station 902 can comprise a CQI detector 920 that can analyze non-reference signal symbols in the same PUCCH subframe to identify CQI information. For example, an expected DTX indicator may be identified by reference signal analyzer 918 (e.g., carried by reference signal symbols, … …) or CQI detector 920 (e.g., carried by non-reference signal symbols, … …). Moreover, it is to be appreciated that reference signal analyzer 918 can be substantially similar to reference signal analyzer 304 of fig. 3 and/or CQI detector 920 can be substantially similar to CQI detector 222 of fig. 2. Further, although not shown, it is contemplated that base station 902 can comprise an ACK/NAK evaluator that can be substantially similar to ACK/NAK evaluator 224 of fig. 2, and/or a DTX recognizer that can be substantially similar to DTX recognizer 226 of fig. 2. Base station 902 can further comprise a modulator 922. A modulator 922 can multiplex a frame for transmission by a transmitter 924 via antenna 908 to access terminals 904 as described supra. Although depicted as being separate from the processor 914, it is to be appreciated that the reference signal analyzer 918, the CQI detector 920 and/or the modulator 922 can be part of the processor 914 or perhaps multiple processors (not shown).

Fig. 10 shows an example wireless communication system 1000. The wireless communication system 1000 depicts one base station 1010 and one access terminal 1050 for sake of brevity. However, it is to be appreciated that system 1000 can include more than one base station and/or more than one access terminal, wherein additional base stations and/or access terminals can be substantially similar or different from example base station 1010 and access terminal 1050 described below. Additionally, it is to be appreciated that base station 1010 and/or access terminal 1050 can facilitate wireless communication between base station and access terminal using the systems (fig. 1-4, 8-9, and 11-12) and/or methods (fig. 6-7) described herein.

At base station 1010, traffic data for a number of data streams is provided from a data source 1012 to Transmit (TX) data processor 1014. According to an example, each data stream can be transmitted over a respective antenna. TX data processor 1014 formats, codes, and interleaves the traffic data stream based on a particular coding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot data using orthogonal frequency division multiple access (OFDM) techniques. Additionally or alternatively, the pilot symbols may be Frequency Division Multiplexed (FDM), Time Division Multiplexed (TDM), or Code Division Multiplexed (CDM). The pilot data is typically a known data pattern that is processed in a known manner and can be used at access terminal 1050 to estimate channel response. The multiplexed pilot and coded data for each data stream can be modulated (e.g., symbol mapped) based on a particular modulation scheme (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream can be determined by instructions performed or provided by processor 1030.

The modulation symbols for the data streams can be provided to a TX MIMO processor 1020, which TX MIMO processor 1020 can further process the modulation symbols (e.g., for OFDM). TX MIMO processor 1020 then passes N_TA stream of modulation symbols is provided to N_TAnd Transmitters (TMTR)1022a through 1022 t. In various embodiments, TX MIMO processor 1020 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

Each transmitter 1022 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. In addition, from N respectively_TN from transmitters 1022a through 1022t are transmitted by antennas 1024a through 1024t_TA modulated signal.

At access terminal 1050, by N_RThe transmitted modulated signals are received by antennas 1052a through 1052r and the received signal from each antenna 1052 is provided to a respective receiver (RCVR)1054a through 1054 r. Each receiver 1054 conditions (e.g., filters, amplifies, and downconverts) a respective signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide corresponding "received" symbolsAnd (4) streaming.

RX data processor 1060 can receive data from N_RN of receiver 1054_ROne received symbol stream and processing the N based on a particular receiver processing technique_RA stream of received symbols to provide N_TA stream of "detected" symbols. RX data processor 1060 can demodulate, deinterleave, and decode each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 1060 is complementary to that performed by TX MIMO processor 1020 and TX data processor 1014 at base station 1010.

As discussed above, processor 1070 can periodically determine which available technology to utilize. Further, processor 1070 can formulate a reverse link message comprising a matrix index portion and a rank value portion.

The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message may be processed by a TX data processor 1038, which also receives traffic data for a number of data streams from a data source 1036, modulated by a modulator 1080, conditioned by transmitters 1054a through 1054r, and transmitted back to base station 1010.

At base station 1010, the modulated signals from access terminal 1050 are received by antennas 1024, conditioned by receivers 1022, demodulated by a demodulator 1040, and processed by a RX data processor 1042 to extract the reverse link message transmitted by access terminal 1050. Further, processor 1030 can process the extracted message to determine which precoding matrix to use for determining the beamforming weights.

Processors 1030 and 1070 can direct (e.g., control, coordinate, manage, etc.) operation at base station 1010 and access terminal 1050, respectively. Respective processors 1030 and 1070 can be associated with memory 1032 and 1072 that store program codes and data. Processors 1030 and 1070 can also perform computations to derive frequency and impulse response estimates for the uplink and downlink, respectively.

In an aspect, logical channels are classified into control channels and traffic channels. Logical control channels may include a Broadcast Control Channel (BCCH), which is a DL channel used to broadcast system control information. Further, the logical control channel may include a Paging Control Channel (PCCH), which is a DL channel that conveys paging information. Further, the logical control channels may include a Multicast Control Channel (MCCH), which is a point-to-multipoint DL channel used for transmitting Multimedia Broadcast and Multicast Service (MBMS) scheduling and control information for one or several MTCHs. Typically, this channel is only used by UEs receiving MBMS (e.g. the original MCCH + MSCH) after establishing a Radio Resource Control (RRC) connection. In addition, the logical control channels may include a Dedicated Control Channel (DCCH), which is a point-to-point bi-directional channel that transmits dedicated control information and may be used by UEs having an RRC connection. In an aspect, the logical traffic channels may include a Dedicated Traffic Channel (DTCH), which is a point-to-point bi-directional channel dedicated to one UE for communicating user information. Also, the logical traffic channels may include a Multicast Traffic Channel (MTCH) for a point-to-multipoint DL channel for transmitting traffic data.

In an aspect, transport channels are classified as DL and UL. DL transport channels include a Broadcast Channel (BCH), a downlink shared data channel (DL-SDCH) and a Paging Channel (PCH). The PCH may support UE power saving by being broadcast over the entire cell and mapped to physical layer (PHY) resources that may be used for other control/traffic channels (e.g., Discontinuous Reception (DRX) cycles may be indicated to the UE by the network, … …). The UL transport channels may include a Random Access Channel (RACH), a request channel (REQCH), an uplink shared data channel (UL-SDCH), and a plurality of PHY channels.

The PHY channel may include a set of DL channels and UL channels. For example, DL PHY channels may include: a common pilot channel (CPICH); a Synchronization Channel (SCH); common Control Channel (CCCH); shared DL Control Channel (SDCCH); multicast Control Channel (MCCH); shared UL Assignment Channel (SUACH); acknowledgement channel (ACKCH); DL physical shared data channel (DL-PSDCH), UL Power Control Channel (UPCCH); a Paging Indicator Channel (PICH); and/or a Load Indicator Channel (LICH). By way of further illustration, the UL PHY channels may include: a Physical Random Access Channel (PRACH) Channel Quality Indicator Channel (CQICH); acknowledgement channel (ACKCH); an Antenna Subset Indicator Channel (ASICH); shared request channel (SREQCH) UL physical shared data channel (UL-PSDCH); and/or a wideband pilot channel (BPICH).

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processing unit may be implemented within: one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

When the embodiments are implemented in software, firmware, middleware or microcode, program code or code segments, they can be stored in a machine-readable medium, such as a storage component. A code segment may represent a program, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc.

For a software implementation, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art.

Referring to fig. 11, illustrated is a system 1100 that enables signaling Discontinuous Transmission (DTX) and Channel Quality Indicator (CQI) information to a base station in a wireless communication environment. System 1100 can reside within an access terminal, for instance. It is to be appreciated that system 1100 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System 1100 includes a logical grouping 1102 of electrical components that can act in conjunction. For example, logical grouping 1102 can include an electrical component for encoding an uplink control channel subframe to include CQI information and at least one indicator distinguishing successful decoding of a Downlink (DL) control channel and a Downlink (DL) data channel, failed decoding of the downlink control channel, and failed decoding of the downlink data channel 1104. Moreover, logical grouping 1102 can optionally include an electrical component for incorporating a DTX indicator with the CQI information on the common set of symbols within the uplink control channel subframe 1106. Moreover, logical grouping 1102 can optionally include an electrical component for including a DTX indicator on reference signal symbols within the uplink control channel subframe 1108. Logical grouping 1102 can also include an electrical component for transmitting the uplink control channel subframe to a base station 1110. Additionally, system 1100 can include a memory 1112 that retains instructions for executing functions associated with electrical components 1104, 1106, 1108, and 1110. While shown as being external to memory 1112, it is to be understood that one or more of electrical components 1104, 1106, 1108, and 1110 can exist within memory 1112.

Referring to fig. 12, illustrated is a system 1200 that enables detecting Discontinuous Transmission (DTX) signaled by an access terminal in a wireless communication environment. For example, system 1200 can reside at least partially within a base station. It is to be appreciated that system 1200 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System 1200 includes a logical grouping 1202 of electrical components that can act in conjunction. For instance, logical grouping 1202 can include an electrical component for obtaining an uplink control channel subframe from an access terminal 1204. Moreover, logical grouping 1202 can comprise an electrical component for decoding the uplink control channel subframe to recognize Channel Quality Indicator (CQI) feedback and at least one indicator that distinguishes between successful decoding, downlink control channel false detection, and downlink data channel false detection encountered by the access terminal 1206. Additionally, system 1200 can include a memory 1208 that retains instructions for executing functions associated with electrical components 1204 and 1206. While shown as being external to memory 1208, it is to be understood that one or more of electrical components 1204 and 1206 can exist within memory 1208.

What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim.

Claims (50)

1. A method that facilitates signaling Discontinuous Transmission (DTX) to a base station in a wireless communication environment, comprising:

encoding Channel Quality Indicator (CQI) information and a DTX indicator within an uplink control channel subframe corresponding to a downlink control channel when it is determined that the downlink control channel has not been successfully decoded; and

transmitting the encoded uplink control channel subframe to a base station.

2. The method of claim 1, further comprising encoding the CQI information and one of an Acknowledgement Character (ACK) indicator or a negative acknowledgement character (NAK) indicator within the uplink control channel subframe corresponding to the downlink control channel when it is determined that the downlink control channel has been successfully decoded.

3. The method of claim 2, further comprising determining whether the downlink control channel was successfully decoded by recognizing whether an assignment corresponding to the uplink control channel sent via the downlink control channel was received and decoded.

4. The method of claim 2, further comprising:

encoding reference signal symbols within a slot to include one of the DTX indicator, the ACK indicator, or the NAK indicator; and

encoding non-reference signal symbols within the slot to include the CQI information.

5. The method of claim 4, further comprising:

using a first mapping for the reference signal symbols within the slot when incorporating the DTX indicator;

using a second mapping for the reference signal symbols within the slot when incorporating the ACK indicator; and

when incorporating the NAK indicator, a third mapping is used for the reference signal symbols within the time slot.

6. The method of claim 5, further comprising:

setting a first reference signal symbol within the slot to 1 and a second reference signal symbol within the slot to j when the first mapping is used to incorporate the DTX indicator;

setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to-1 when the ACK indicator is incorporated with the second mapping; and

setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to 1 when the third mapping is used to incorporate the NAK indicator.

7. The method of claim 5, further comprising:

setting a first reference signal symbol within the slot to 1 and a second reference signal symbol within the slot to 1 when the first mapping is used to incorporate the DTX indicator;

setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to-1 when the ACK indicator is incorporated with the second mapping; and

setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to 1 when the third mapping is used to incorporate the NAK indicator.

8. The method of claim 4, further comprising: when in a DTX mode of operation in conjunction with downlink multiple-input multiple-output (MIMO), a first reference signal symbol within the slot is set to 1 and a second reference signal symbol within the slot is set to 1.

9. The method of claim 2, further comprising:

adding a transmit status bit to a set of bits representing the CQI information;

setting a value of the transmit status bit to signal one of DTX operation or non-DTX operation; and

the transmit status bits and the bits representing the CQI information are jointly encoded on non-reference signal symbols in a slot.

10. The method of claim 9, wherein the transmission state bits can switch between one of linearly adding or not adding particular reed-muller (RM) basis vectors based on one of DTX operation or non-DTX operation.

11. A wireless communications apparatus, comprising:

a memory holding instructions related to: encoding Channel Quality Indicator (CQI) information and a Discontinuous Transmission (DTX) indicator within an uplink control channel subframe corresponding to a downlink control channel when it is determined that the downlink control channel has not been successfully decoded; encoding the CQI information and one of an Acknowledgement Character (ACK) indicator or a non-acknowledgement character (NAK) indicator within the uplink control channel subframe corresponding to the downlink control channel when it is determined that the downlink control channel has been successfully decoded; and transmitting the encoded uplink control channel subframe to a base station; and

a processor coupled to the memory, the processor configured to execute the instructions retained in the memory.

12. The wireless communications apparatus of claim 11, wherein the memory further retains instructions related to: determining whether the downlink control channel is successfully decoded by recognizing whether an assignment corresponding to the uplink control channel sent via the downlink control channel is received and decoded.

13. The wireless communications apparatus of claim 11, wherein the memory further retains instructions related to: encoding reference signal symbols within a slot to include one of the DTX indicator, the ACK indicator, or the NAK indicator; and encoding non-reference signal symbols within the slot to include the CQI information.

14. The wireless communications apparatus of claim 13, wherein the memory further retains instructions related to: using a first mapping for the reference signal symbols within the slot when incorporating the DTX indicator; using a second mapping for the reference signal symbols within the slot when incorporating the ACK indicator; and using a third mapping for the reference signal symbols within the time slot when incorporating the NAK indicator.

15. The wireless communications apparatus of claim 14, wherein the memory further retains instructions related to: setting a first reference signal symbol within the slot to 1 and a second reference signal symbol within the slot to j when the first mapping is used to incorporate the DTX indicator; setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to-1 when the ACK indicator is incorporated with the second mapping; and setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to 1 when the third mapping is used to incorporate the NAK indicator.

16. The wireless communications apparatus of claim 14, wherein the memory further retains instructions related to: setting a first reference signal symbol within the slot to 1 and a second reference signal symbol within the slot to 1 when the first mapping is used to incorporate the DTX indicator; setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to-1 when the ACK indicator is incorporated with the second mapping; and setting the first reference signal symbol within the slot to 1 and the second reference signal symbol within the slot to 1 when the third mapping is used to incorporate the NAK indicator.

17. The wireless communications apparatus of claim 13, wherein the memory further retains instructions related to: when in a DTX mode of operation in conjunction with downlink multiple-input multiple-output (MIMO), a first reference signal symbol within the slot is set to 1 and a second reference signal symbol within the slot is set to 1.

18. The wireless communications apparatus of claim 11, wherein the memory further retains instructions related to: adding a transmit status bit to a set of bits representing the CQI information; setting a value of the transmit status bit to signal one of DTX operation or non-DTX operation; and encoding the transmission status bits together with the bits representing the CQI information on non-reference signal symbols in a slot.

19. The wireless communications apparatus of claim 18, wherein the transmission state bits can switch between one of linearly adding or not adding particular reed-muller (RM) basis vectors based on one of DTX operation or non-DTX operation.

20. A wireless communications apparatus that enables signaling Discontinuous Transmission (DTX) and Channel Quality Indicator (CQI) information to a base station in a wireless communication environment, comprising:

means for encoding an uplink control channel subframe to include CQI information and at least one indicator distinguishing between successful decoding of a downlink control channel and a downlink data channel, failed decoding of the downlink control channel, and failed decoding of the downlink data channel; and

means for transmitting the uplink control channel subframe to a base station.

21. The wireless communications apparatus of claim 20, further comprising means for incorporating a DTX indicator with the CQI information on a common set of symbols within the uplink control channel subframe.

22. The wireless communications apparatus of claim 21, wherein the common set of symbols comprises non-reference signal symbols.

23. The wireless communications apparatus of claim 20, further comprising means for including a DTX indicator on reference signal symbols within the uplink control channel subframe.

24. The wireless communications apparatus of claim 23, wherein the CQI information is included on non-reference signal symbols within the uplink control channel subframe.

25. The wireless communications apparatus of claim 23, wherein a particular mapping corresponding to the DTX indicator from a set of possible mappings is utilized for the reference signal symbols.

26. The wireless communications apparatus of claim 25, wherein the particular mapping comprises setting a first reference signal symbol within a slot to 1 and a second reference signal symbol within the slot to j.

27. The wireless communications apparatus of claim 25, wherein the particular mapping comprises setting a first reference signal symbol within a slot to 1 and setting a second reference signal symbol within the slot to 1.

28. A computer program product, comprising:

a computer-readable medium, comprising:

code for encoding an uplink control channel subframe to include Channel Quality Indicator (CQI) information and at least one indicator that distinguishes between successful decoding of a downlink control channel and a downlink data channel, failed decoding of the downlink control channel, and failed decoding of the downlink data channel; and

code for communicating the uplink control channel subframe to a base station.

29. The computer program product of claim 28, wherein the computer-readable medium further comprises code for incorporating a DTX indicator with the CQI information on a common set of symbols within the uplink control channel subframe.

30. The computer program product of claim 28, wherein the computer-readable medium further comprises code for including a DTX indicator on reference signal symbols within the uplink control channel subframe.

31. The computer program product of claim 30, wherein a particular mapping corresponding to the DTX indicator from a set of possible mappings is used for the reference signal symbols.

32. The computer program product of claim 31, wherein the particular mapping comprises setting a first reference signal symbol within a slot to 1 and a second reference signal symbol within the slot to j.

33. The computer program product of claim 31, wherein the particular mapping comprises setting a first reference signal symbol within a slot to 1 and a second reference signal symbol within the slot to 1.

34. In a wireless communication system, an apparatus comprising:

a processor configured to:

determining whether to successfully decode a downlink control channel by recognizing whether an assignment corresponding to an uplink control channel sent via the downlink control channel is received and decoded;

encoding Channel Quality Indicator (CQI) information and a DTX indicator within an uplink control channel subframe corresponding to the downlink control channel when it is determined that the downlink control channel has not been successfully decoded;

encoding the CQI information and one of an Acknowledgement Character (ACK) indicator or a non-acknowledgement character (NAK) indicator within the uplink control channel subframe corresponding to the downlink control channel when it is determined that the downlink control channel has been successfully decoded; and

transmitting the encoded uplink control channel subframe to a base station.

35. A method that facilitates detecting Discontinuous Transmission (DTX) in a wireless communication environment, comprising:

receiving an uplink control channel subframe from an access terminal;

decoding the uplink control channel subframe to identify Channel Quality Indicator (CQI) feedback from the access terminal; and

decoding the uplink control channel subframe to detect at least one indicator that distinguishes between successful decoding, downlink control channel decoding errors, and downlink data channel decoding errors encountered by the access terminal.

36. The method of claim 35, further comprising the access terminal employing DTX operation when the uplink control channel subframe fails to correspond to an assignment sent to the access terminal via a downlink transmission.

37. The method of claim 35, wherein the at least one indicator is detected from a first set of symbols within a slot, and the CQI feedback is identified from a second set of symbols within the slot, wherein the first set and the second set are mutually exclusive.

38. The method of claim 37, wherein the first set of symbols comprises reference signal symbols and the second set of symbols comprises non-reference signal symbols.

39. The method of claim 35, wherein the at least one indicator is detected based at least in part on a value of a transmission status bit added to CQI information bits carried by a set of symbols within the uplink control channel subframe.

40. A wireless communications apparatus, comprising:

a memory holding instructions related to: obtaining an uplink control channel subframe from an access terminal; decoding the uplink control channel subframe to identify Channel Quality Indicator (CQI) feedback from the access terminal; and decoding the uplink control channel subframe to detect at least one indicator that distinguishes between successful decoding, downlink control channel decoding errors, and downlink data channel decoding errors encountered by the access terminal; and

a processor coupled to the memory, the processor configured to execute the instructions retained in the memory.

41. The wireless communications apparatus of claim 40, wherein the at least one indicator is detected from a first set of symbols within a slot and the CQI feedback is identified from a second set of symbols within the slot, wherein the first set and the second set are mutually exclusive.

42. The wireless communications apparatus of claim 41, wherein the first set of symbols comprises reference signal symbols and the second set of symbols comprises non-reference signal symbols.

43. The wireless communications apparatus of claim 40, wherein the at least one indicator is detected based at least in part on a value of a transmission status bit added to CQI information bits carried by a set of symbols within the uplink control channel subframe.

44. A wireless communications apparatus that enables detecting Discontinuous Transmission (DTX) signaled by an access terminal in a wireless communication environment, comprising:

means for obtaining an uplink control channel subframe from an access terminal; and

means for decoding the uplink control channel subframe to recognize Channel Quality Indicator (CQI) feedback and at least one indicator that distinguishes between successful decoding, downlink control channel false detection, and downlink data channel false detection encountered by the access terminal.

45. The wireless communications apparatus of claim 44, wherein the at least one indicator is detected from reference signal symbols within a slot and the CQI feedback is identified from non-reference signal symbols within the slot.

46. The wireless communications apparatus of claim 44, wherein the at least one indicator is detected based at least in part on a value of a transmission status bit added to CQI information bits carried by a set of symbols within the uplink control channel subframe.

47. A computer program product, comprising:

a computer-readable medium, comprising:

code for receiving an uplink control channel subframe from an access terminal; and

code for decoding the uplink control channel subframe to identify Channel Quality Indicator (CQI) feedback and at least one indicator that distinguishes between successful decoding, downlink control channel false detection, and downlink data channel false detection experienced by the access terminal.

48. The computer-program product of claim 47, wherein the at least one indicator is detected from reference signal symbols within a slot and the CQI feedback is identified from non-reference signal symbols within the slot.

49. The computer program product of claim 47, wherein the at least one indicator is detected based, at least in part, on a value of a transmission status bit added to CQI information bits carried by a set of symbols within the uplink control channel subframe.

50. In a wireless communication system, an apparatus comprising:

a processor configured to:

obtaining an uplink control channel subframe from an access terminal;

decoding the uplink control channel subframe to discover Channel Quality Indicator (CQI) feedback from the access terminal; and

decoding the uplink control channel subframe to recognize at least one indicator that distinguishes between successful decoding, downlink control channel decoding errors, and downlink data channel decoding errors encountered by the access terminal.