HK1081009A - Quality indicator bit(qib) generation in wireless communication systems - Google Patents

Description

Quality Indicator Bit (QIB) generation in a wireless communication system

Technical Field

The present invention relates generally to communication, and more specifically to techniques for generating Quality Indicator Bits (QIBs) in a wireless communication system.

Background

In a wireless (e.g., cellular) communication system, a user communicates with another user or entity using a wireless terminal (e.g., a cellular telephone) via transmissions on forward and reverse links to one or more base stations. The forward link refers to transmission from the base station to the terminal, and the reverse link refers to transmission from the terminal to the base station. The forward and reverse links are typically assigned different frequencies.

In a Code Division Multiple Access (CDMA) system, the total capacity of the forward link of each base station is determined by its total transmit power, within the limits of the physical channel resources. Each base station may transmit data to multiple users simultaneously on the same frequency band. Then each active user is assigned a portion of the total transmit power of the base station so that the sum of the power assigned to all users is less than or equal to the total transmit power.

To maximize forward link capacity, the amount of transmit power used by each terminal is adjusted by a power control mechanism that attempts to achieve a desired level of performance with a minimum amount of transmit power. For a CDMA system, the power control mechanism is typically implemented by two power control loops. The first loop adjusts the transmit power to maintain the quality of the signal received by the terminal at a particular threshold level. Typically by the ratio of energy per bit to noise plus interference (E)_b/I_o) To quantify the received signal quality. The threshold level is often referred to as a power control set point (or simply set point). The second loop adjusts the set point to maintain the desired level of performance. This performance level is typically given by a particular Frame Error Rate (FER), e.g., 1% FER. The power control mechanism of the forward link thus attempts to reduce power consumption and interference while maintaining a desired level of performance for the terminal. This will thus maximize the forward link capacity.

Some CDMA systems support some type of feedback of power control commands to control the transmit power of the base station for a given terminal. For example, in a cdma2000 system, a terminal may send back power control bits, Erasure Indicator Bits (EIB), or Quality Indicator Bits (QIB) for power control purposes. The power control bits are typically generated by comparing the received signal quality for a particular transmission (e.g., data, pilot, etc.) to the setpoint. Each power control bit would then require the base station to adjust its transmit power for the terminal up or down by a certain amount (e.g., 1 dB). The erasure indicator bit indicates whether a data frame previously transmitted by the base station is correctly received by the terminal or an error occurs. The quality indicator bit indicates whether a previous data frame transmitted by the base station was received with sufficient or insufficient signal quality. Depending on the particular power control mode selected for use, the terminal is thus configured to periodically send one of these three types of power control commands back to the base station.

If the terminal is configured to send back quality indicator bits, each quality indicator bit is typically generated based on a data frame sent on a designated forward channel. However, the forward channel may operate in a non-continuous manner, whereby data frames may not be transmitted on the forward channel for certain periods of time. Such non-continuous transmission is also called Discontinuous Transmission (DTX). DTX frames (i.e., null or empty frames) are not transmitted on the forward channel and a DTX event indicates no transmission for a given frame interval. When a DTX event is detected, the normal method of generating quality indicator bits based on received data frames cannot be used since there is no transmission.

In a simple method of handling discontinuous transmission on the forward channel, all frames determined to be DTX events will be classified as having good received signal quality. However, quality indicator bits generated in this manner will not provide useful information for power control. Based on these quality indicator bits, the transmission power of the terminal cannot be adjusted correctly.

There is therefore a need in the art for generating quality indicator bits for discontinuous transmission on a forward channel in a wireless communication system.

Disclosure of Invention

Techniques are provided herein that enable generation of quality indicator bits for power control even when non-continuous transmissions are received on a forward channel being monitored. When no data frame is detected on the forward channel, a second transmission using the associated forward channel can be used to estimate the quality of the received signal.

In a method of generating quality indicator bits in a wireless communication system, such as a cdma2000 system, as opposed to IS-2000, it IS first determined whether a complete frame of data has been received from a first transmission within a current frame interval. The first transmission may be a discontinuous transmission on a forward dedicated control channel (F-DCCH) as defined by IS-2000. If a complete data frame is received, quality indicator bits are generated based on the complete data frame. Otherwise, a quality indication bit is generated based on the second transmission. The second transmission may include power control bits transmitted at an associated forward power control subchannel even if a data frame is not transmitted in the first transmission. Next, the received signal quality of the first transmission is estimated from the received signal quality of the second transmission.

The quality indicator bit may be generated based on the received power control bit by (1) determining a received signal quality for the power control bit received during the current frame interval, (2) comparing the received signal quality for the power control bit to a threshold, and (3) setting the quality indicator bit, for example, to "0" to indicate sufficient received signal quality or to "1" to indicate insufficient received signal quality based on the result of the comparison. The threshold can be dynamically updated. For example, the threshold may be updated based on (1) a setpoint for the first transmission, (2) a received signal quality for a previously received full data frame, (3) a received signal quality for power control bits associated with a previously received full data frame, and so on. The threshold value may be initialized to a value derived based on a minimum setpoint required for the first transmission.

Various aspects and embodiments of the invention are described in detail below. The invention also provides methods, program codes, digital signal processors, receiver units, terminals, base stations, systems, and other devices and components that implement various aspects, embodiments, and features of the invention, as described in detail below.

Drawings

The features, nature, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:

FIG. 1 illustrates a wireless communication system;

fig. 2 illustrates a forward link power control mechanism capable of generating QIBs based on non-continuous transmission on a forward channel;

FIG. 3A illustrates the IS-2000 defined F-FCH, F-DCCH and forward power control subchannel;

fig. 3B illustrates a reverse power control subchannel and a reverse pilot channel defined by IS-2000;

fig. 4 illustrates generation and transmission of QIBs for discontinuous transmission on the F-DCCH;

fig. 5 shows a process of generating QIBs for discontinuous transmission on the F-DCCH; and

fig. 6 is a block diagram of a base station and a terminal in a wireless communication system.

Detailed Description

Fig. 1 is a diagram of a wireless communication system 100. System 100 includes a plurality of base stations 104 in communication with a plurality of terminals 106. A base station is a fixed station used for communicating with the terminals. A base station may also be referred to as a Base Transceiver System (BTS), an access point, a node B, or some other terminology. A terminal may also be called a mobile station, a remote station, an access terminal, a User Equipment (UE), or some other terminology. Each terminal may communicate with one or more base stations on the forward and/or reverse links at any given moment. Depending on whether the terminal is active, whether soft handover of data transmission is supported, and whether the terminal is in a soft handover state.

The system controller 102 is coupled to the base stations 104 and may also be coupled to a Public Switched Telephone Network (PSTN) and/or a Packet Data Network (PDN). System controller 102 may also be referred to as a Base Station Controller (BSC), a Mobile Switching Center (MSC), a Radio Network Controller (RNC), or some other terminology. The system controller 102 provides coordination and control for the base stations connected thereto. The system 102 also controls the routing of calls through the base stations (1) between terminals, and (2) between terminals and other users and entities connected to the PSTN (e.g., conventional telephones) and PDN.

The techniques for generating Quality Indicator Bits (QIBs) described herein may be implemented in various wireless communication systems. Thus, system 100 may be a Code Division Multiple Access (CDMA) system, a Time Division Multiple Access (TDMA) system, or some other type of system. A CDMA system may be designed to implement one or more standards, such as IS-2000, IS-856, W-CDMA, IS-95, and so on. TDMA systems may be designed to implement one or more standards, such as global system for mobile communications (GSM). These standards are well known in the art and are incorporated herein by reference. For clarity, the techniques for generating quality indicator bits are described specifically for cdma2000 systems implementing IS-2000.

On the forward link, the capacity of each base station is limited by its total transmit power. In order to maximize the forward link capacity while providing the required level of performance to each active terminal, the dedicated transmit power for each user from the base station to a particular terminal may be controlled as low as possible. If the quality of the signal received at the terminal is too poor, the likelihood of correctly decoding the received transmission is also reduced and performance may be degraded (e.g., higher FER). On the other hand, if the received signal quality is too high, then the transmit power level may also be too high. In this case, using excessive transmit power for transmission will reduce capacity and also create additional interference for transmissions from nearby base stations.

A forward link power control loop is typically used to adjust the transmit power for user-specific transmissions to each terminal so that the received signal quality of the terminal remains at the setpoint. cdma2000 systems support the transmission of three types of power control commands for the forward link power control loop. These instruction types include Power Control (PC) bits, Erasure Indicator Bits (EIB), and Quality Indicator Bits (QIB). Based on the selected forward power control mode, the terminal is typically configured to periodically send one or a combination of two of the three types of power control commands back to the base station.

The reverse link power control loop is also typically used to adjust the transmit power of each terminal to maintain the quality of the signal received at the base station at a desired level. The forward and reverse link power control loops operate independently. Each power control loop requires a feedback stream from the receiver that the transmitter uses to adjust its transmit power for the receiver.

In IS-2000, a terminal may be assigned a forward fundamental channel (F-FCH) and a forward dedicated control channel (F-DCCH) for data transmission on the forward link. If the F-FCH is used for data transmission, each data frame transmitted on the F-FCH is detected and used to generate a QIB for the data frame. In particular, each transmitted data frame includes a Cyclic Redundancy Check (CRC) value that the terminal can use to determine whether the data frame was received correctly (completely) or in error (erased). The QIB is set to "0" if the CRC passes (to indicate sufficient received signal quality), or is set to "1" if the CRC fails (to indicate insufficient received signal quality). If the F-FCH is not used for data transmission, frame detection on the F-DCCH can be performed in a similar manner using the CRC included in each data frame transmitted on the F-DCCH.

IS-2000 also requires the terminal to initialize and manage the operation of the forward traffic channel based on the received signal quality of the F-DCCH when selecting the forward traffic channel to transmit the forward power control subchannel. As part of this requirement, in the traffic channel initialization state, the terminal can only initiate transmission on the reverse link after receiving two consecutive data frames with sufficient received signal quality. Also, in the traffic state, the terminal is required to inhibit its transmission when twelve consecutive data frames with insufficient received signal quality are received. It is also necessary that the terminal declares that the current call has been dropped and enters a system determination state if no data frame with sufficient signal quality is received in any 5 second interval.

Therefore, it IS desirable to determine the received signal quality for the F-DCCH to (1) generate the QIB when the F-FCH IS not used for data transmission, and (2) manage the operation of the F-DCCH as required by IS-2000. The received signal quality on the F-DCCH is typically determined based on the status of the received data frame (i.e., intact or erased). However, the F-DCCH may be operated in a Discontinuous Transmission (DTX) mode. When the F-DCCH is in a discontinuous transmission state, no data frame is transmitted on the forward channel and power control commands for the reverse link power control loop are transmitted only on the forward power control subchannel. When DTX frames (i.e., null or zero frames) are transmitted on the F-DCCH, the QIB cannot be generated in the normal manner based on the CRC value.

The techniques described herein are capable of generating QIBs for power control even when the forward channel (e.g., F-DCCH) being monitored operates in a non-continuous manner. When no data frame is detected on the channel, additional transmissions may be used to estimate the quality of the received signal. For example, when no data frame is detected, the power control commands for the reverse link power control loop (i.e., RL power control commands) can be used to estimate the quality of the received signal. The QIB may be generated based on the received data frame (if a complete data frame is detected) or the RL power control command (if a complete data frame is not detected) for each frame interval.

Fig. 2 is a diagram of a forward link power control mechanism 200 capable of generating QIBs based on discontinuous transmission on a forward channel. These QIBs represent the quality of the received signal and can therefore be used for power control.

The base station generates and transmits a forward link signal to the terminal. The forward link signal includes data (if any), signaling, pilot, and RL power control commands, all of which are transmitted on their assigned forward channels. For a cdma2000 system, both data and signaling may be sent in data frames on the F-FCH or F-DCCH (5 or 20msec), pilots are sent on the forward pilot channel (F-PICH), and RL power control commands are sent on the forward power control subchannel. Since the pilot is intended for reception by all terminals within the coverage of the base station, the transmit power for the F-PICH is typically fixed at a particular power level. However, data and signaling on the F-FCH and F-DCCH are user-specific and the transmit power for these forward channels can be adjusted for each terminal (block 216).

The forward link signal is transmitted to the terminal over the wireless channel (shadow frame 218). The quality of the signal received by the terminal fluctuates constantly due to variations in the radio channel, typically over time, and particularly for mobile terminals.

At the terminal, an RX data processor 222 processes the received signal and attempts to detect and recover each data frame transmitted on the F-FCH and F-DCCH. RX data processor 222 determines the status (i.e., complete or erased) of each received data frame and provides the frame status to QIB generator 214. Received signal quality measurement unit 212 also processes the received signal, determines the quality of the RL power control bits, and provides the Power Control (PC) bit quality to QIB generator 214.

QIB generator 214 receives the frame status from RX data processor 222, the PC bit quality from unit 212, and an initial PCB (power control bit) threshold. QIB generator 214 then generates a QIB based on the complete data frame received by the terminal, as indicated by the frame status. In addition, QIB generator 214 generates QIBs based on the PC bit quality and the PCB threshold described above. QIB generator 214 also updates the PCB threshold. QIBs are transmitted back to the base station, which can then use them to adjust the transmit power of the terminal.

Fig. 3A illustrates a diagram of the IS-2000 defined F-FCH, F-DCCH, and forward power control subchannels. The transmit timeline (timeline) for the F-FCH and F-DCCH is partitioned into (20msec) frame intervals. Each frame interval is subdivided into 16 (1.25msec) Power Control Groups (PCGs) and the power control groups are numbered 0 through 15. Data may be transmitted in frames of 5msec or 20msec on each of the F-FCH and F-DCCH.

The forward power control subchannel may be transmitted on the F-FCH or F-DCCH. The forward power control subchannel includes, for each power control group, a power control bit for the reverse link power control loop (i.e., a FL power control bit). Each FL power control bit occupies 1/12 power control groups and is pseudo-randomly distributed among the power control groups. The remaining portion of each power control group is then used to transmit data for the F-FCH or F-DCCH.

Fig. 3B illustrates a diagram of the reverse power control subchannel and the reverse pilot channel defined by IS-2000. As shown in fig. 3B, the reverse power control subchannel is time division multiplexed with the reverse pilot channel. The transmit timeline (time) on this multiplexed channel is also partitioned into (20msec) frame intervals, each frame interval being subdivided into 16 power control groups. For each power control group, pilot data is transmitted at the front 3/4 of the power control group and power control commands are transmitted at the back 1/4 of the power group. The 16 power control commands for each frame interval may correspond to 16 power control bits, an EIB, or a QIB.

Fig. 4 illustrates a diagram of generating and transmitting QIBs on a reverse power control subchannel for discontinuous transmission on the F-DCCH. A data frame is received at frame interval i and processed to determine if a complete data frame has been received. In this example, no complete data frame is detected at frame interval i. The forward power control subchannel is also processed at frame interval i and the received signal quality for the 16 FL power control bits received at that frame interval is determined. A QIB for the frame interval is generated based on the received signal quality for the power control bits. The QIB is transmitted back to the base station on the reverse power control subchannel at frame interval i + 2. For each frame interval, generation and transmission of a QIB is performed.

Fig. 5 is a flow diagram of a process 500 for generating QIBs for discontinuous transmission on F-DCCH

Examples are given.

First, the PCB threshold for comparing the received signal quality of the FL power control bits is set to an initial PCB threshold (step 512). Because the PCB threshold is dynamically updated as described below, it is not necessary that the initial PCB threshold be an accurate value. However, since transmission on the reverse link is only allowed after two consecutive frames of sufficient quality are received on the F-DCCH, and since the received signal quality on the F-DCCH is determined by the initial PCB threshold (at least for the first frame), a sufficiently high value is used as the initial PCB threshold so that the reverse link transmission will not begin when no signal on the F-DCCH is received. On the other hand, the initial PCB threshold should be low enough to enable the reverse link transmission to begin.

In an embodiment, the initial PCB threshold is derived based on a minimum set point for F-DCCH. Also, the initial PCB threshold may take into account the data rate of the data frame on the F-DCCH, which is determined by the Radio Configuration (RC) of the terminal. The initial PCB threshold may also be set to other values. Step 512 is typically performed at the beginning of the communication session.

When the terminal is in the active state, a QIB is then generated for each frame interval. For each frame interval, the F-DCCH is processed in an attempt to recover data frames that may have been transmitted during the frame interval (step 514). The FL power control bits received at the frame interval are also processed and the received signal quality for the power control bits is measured (i.e., estimated) (step 516). The received signal quality for the power control bits may be determined by (1) measuring the energy (E) of the received power control bits_b) (2) using the total effective noise power spectral density N_tDivided by the received bit energy (E)_b) Wherein the power spectral density (i.e., the received signal quality) is observed via a forward channel used to transmit power control bitsAmount ═ E_b/N_t,). The receiver is able to determine each of these qualities. Determining the quality of a received signal is well known in the art and will not be described in further detail herein.

It is then determined whether a complete frame of data has been received for the current frame interval (step 520). This determination may be made based on a CRC value included in each transmitted data frame. If the CRC passes, a complete data frame is declared, and if the CRC fails, an erased data frame is declared. The CRC may fail for any of a number of reasons. For example, the CRC may fail if (1) the data frame was transmitted by the base station but was received by the terminal in error, or (2) the base station did not transmit any data frame.

If a complete data frame is received, as determined at step 520, the QIB for the current frame interval is set to "0" to indicate that the received signal quality is sufficient (step 522). The PCB threshold is then updated using any of a number of methods, some of which are described in more detail below (step 544). The process then returns to step 514 to process the next frame interval.

If a complete data frame has not been received, as determined at step 520, a determination is made as to whether an erased frame has been received (step 530). If an erased frame is received, the QIB is set to "1" to indicate that the received signal quality is insufficient (step 532). The process then proceeds to step 544.

If no erased data frame is received, as determined in step 530, then the received signal quality for the power control bits is compared to the PCB threshold (step 540). If the received power control bit quality is less than or equal to the PCB threshold, then the QIB is set to "1" to indicate that the received signal quality is insufficient (step 532). Otherwise, if the quality of the received power control bit is above the PCB threshold, the QIB is set to "0" to indicate that the received signal quality is sufficient (step 542). In either case, from steps 532 and 542, the process proceeds to step 544 to update the PCB threshold and then returns to step 514 to process the next frame interval.

The PCB threshold used to compare the received signal quality of the power control bits may be dynamically updated to provide improved performance for time varying wireless channels. In one embodiment, the PCB threshold is updated based on a setpoint for the F-DCCH. For example, at each frame boundary, the PCB threshold may be set equal to the F-DCCH setpoint minus a back-off factor. The compensation factor may be any value determined empirically or by simulation to provide good performance. As a specific example, the PCB threshold may be set equal to the F-DCCH setpoint minus 5 dB. The F-DCCH setpoint can be advantageously used for the PCB threshold because (1) it is adjusted to achieve a desired performance level (e.g., 1% FER), and (2) it has a built-in averaging mechanism. Various other embodiments of generating QIBs for discontinuous transmission are also contemplated and are within the scope of the present invention.

For example, in another embodiment, the PCB threshold is updated based on the received signal quality for a complete data frame, which may be in terms of energy per bit to noise ratio (E)_b/N_t) To be quantized. In another embodiment, when a complete data frame is received, the PCB threshold is updated based on the received signal quality for the power control bits during the frame interval. For both embodiments, step 544 may be moved between steps 520 and 522 in FIG. 5. The PCB threshold may also be dynamically updated based on some other quantity or metric, such as, for example, the received power for the power control bits.

The number used to update the PCB threshold may be averaged to eliminate frame-to-frame variations in measuring this quantity. A linear average may be used to average the measurements over N past frame intervals (which may be the frame intervals for a complete data frame). Alternatively, exponential averaging may be used to give greater weight to the most recent measurements of the complete data. In addition, a compensation factor may be used and may be selected to provide superior performance.

In another embodiment, no attempt is made to distinguish between DTX frames (null or empty frames) and erased frames (transmitted but erroneously received data frames). The power control bits are used to generate QIBs if a complete data frame is not received (i.e., if a DTX frame or an erasure frame is received).

In another embodiment, if a complete data frame is not received, the QIB may be set based on the received signal quality for the bad frame and the received signal quality for the power control bits.

Fig. 6 is a block diagram of an embodiment of a base station 104x and a terminal 106 x. On the forward link, a Transmit (TX) data processor 610 receives various types of data and processes (e.g., formats, encodes, and interleaves) the received data. The processed data is provided to a Modulator (MOD)612 and further processed (e.g., channelized using one or more channelization codes, spectrally spread using PN sequences, etc.). The modulated data is provided to a transmitter unit (TMTR)614 and conditioned (e.g., converted to one or more analog signals, amplified, filtered, frequency up converted, and so on) to generate a forward link signal. The forward link signal is routed through duplexer (D)616 and transmitted via antenna 618 to the terminals.

Although not shown in fig. 6 for simplicity, base station 104x may be capable of processing and transmitting data and signaling to particular terminals on one or more forward channels/subchannels (e.g., F-FCH, F-DCCH, forward power control subchannels, etc.). The processing (e.g., encoding, modulation, etc.) for each forward channel/subchannel may be different from the processing for the other forward channels/subchannels.

At terminal 106x, the forward link signal is received by an antenna 652, routed through a duplexer 654, and provided to a receiver unit (RCVR) 656. Receiver unit 656 conditions (e.g., filters, amplifies, and frequency downconverts) the received signal and further digitizes the conditioned signal to provide samples. A demodulator (Demod)658 further processes (e.g., despreads (despreads), channelizes, and data demodulates) the samples to provide demodulated data. Demodulator 658 may implement a rake receiver that is capable of processing multiple signal samples in the received signal simultaneously. A Receive (RX) data processor 660 then processes (e.g., deinterleaves and decodes) the demodulated data, checks each received frame, and provides output data. RX data processor 660 also provides the status of each received frame to a QIB generator 664. The frame status indicates whether a complete data frame is received at each frame interval.

To generate QIBs, samples from receiver unit 656 are also provided to a signal quality measurement unit 662, which can be used to measure the received signal quality for the power control bits transmitted on the forward power control subchannel. The quality of the received signal can be calculated using various techniques, including those described in U.S. Pat. nos. 5,05,109 and 5,265,119. The received signal quality for the power control bits (shown as PCB quality in fig. 6) is provided to QIB generator 664.

When enabled, QIB generator 664 generates a QIB for each frame interval based on the received data frame or power control bits. More specifically, for each frame interval, a QIB is generated based on a complete data frame (if received) or power control bits (if a complete data frame is not received). QIB generator 664 can implement the process shown in fig. 5 to generate the QIBs. The QIB may also be generated using any other available additional information.

On the reverse link, a TX data processor 680 receives and processes (e.g., formats, encodes) various types of data. A modulator 682 receives the QIBs from QIB generator 664 along with the processed data from TX data processor 680 and further processes (e.g., channelizes and spreads) the received data and QIBs. Within modulator 682, the QIBs may be multiplexed with pilot data and transmitted on the reverse pilot channel, as shown in fig. 3B. The modulated data is then conditioned by a transmitter unit 684 to generate a reverse link signal. The reverse link signal is then routed through duplexer 654 and transmitted via antenna 652 to one or more base stations.

At base station 104x, the reverse link signal is received by antenna 618, routed through duplexer 616, and provided to a receiver unit 638. Receiver unit 638 conditions the received signal, digitizes the conditioned signal, and provides a stream of samples to each channel processor 640. Each channel processor 640 includes a demodulator 642 and a RX signaling processor 644 that receive and process the sample stream for a terminal to recover the transmitted data and QIBs. A power control processor 620 receives the QIBs (and/or power control bits and EIBs) and generates one or more signals that are used to adjust the transmit power of the terminal.

For clarity, various aspects and embodiments of QIB generation are described particularly for CDMA2000 systems implementing IS-2000. In general, these techniques can be used to generate QIBs for discontinuous transmission on a "primary" channel, and to generate QIBs for another transmission on a "secondary" channel, if desired. For cdma2000, the primary channel may be the F-DCCH, and the secondary channel may be the forward power control subchannel. In general, the secondary channel may be any channel that carries a transmission that can be used to estimate the received signal quality when transmission over the primary channel is not available for this purpose. The transmission on the secondary channel need not be continuous.

QIBs may also be generated for discontinuous transmission on the reverse link using the techniques described herein.

The QIB generation techniques described herein may be implemented in various ways. For example, these techniques may be implemented using hardware, software, or a combination thereof. For a hardware implementation, the QIBs may be generated on 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 components designed to perform the functions described herein, or a combination thereof.

For a software implementation, the QIB generation techniques 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 a memory unit (e.g., memory 672 of fig. 6) and executed by a processor (e.g., controller 670). 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.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. It will be apparent to those of ordinary skill in the art that various modifications can be made to these embodiments, and that the general principles defined herein may be applied to other embodiments without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (22)

1. A method for generating quality indicator bits in a wireless communication system, comprising:

determining whether a complete data frame is received from the first transmission at a particular time interval;

if a complete data frame is received, generating a quality indicator bit based on the complete data frame; and the number of the first and second groups,

if a complete data frame is not received, a quality indicator bit is generated based on the second transmission.

2. The method of claim 1, wherein the first transmission is non-contiguous.

3. The method of claim 1, wherein the second transmission comprises a power control bit.

4. The method of claim 3, wherein generating the quality indicator bits based on the second transmission comprises

Determining a received signal quality for power control bits received within a particular time interval,

comparing the received signal quality for the power control bits to a threshold, and

a quality indicator bit is set based on the result of the comparison.

5. The method of claim 4, wherein the threshold is dynamically updated.

6. The method of claim 5, wherein the threshold is updated based on a target received signal quality for the first transmission.

7. The method of claim 5, wherein the threshold is updated based on a received signal quality for a previously received complete data frame.

8. The method of claim 5, wherein the threshold is updated based on a received signal quality for power control bits associated with a previously received full data frame.

9. The method of claim 4, wherein the threshold is initialized to a value derived based on a minimum received signal quality required for the first transmission.

10. The method of claim 1, wherein the complete data frame is determined based on a CRC value included in each transmitted data frame.

11. The method of claim 1, wherein the first transmission IS on a forward dedicated control channel (F-DCCH) defined by IS-2000.

12. A method for generating quality indicator bits in a wireless communication system, comprising:

determining whether a data frame from a first discontinuous transmission is received at a particular time interval;

if a data frame is received, generating a quality indicator bit based on the received data frame; and

if no data frame is received, a quality indicator bit is generated based on the second transmission.

13. A method for generating quality indicator bits in a CDMA communication system, comprising:

processing a data frame received on a forward channel at a particular frame interval;

if a complete data frame is received, generating a quality indicator bit based on the complete data frame; and

if a complete data frame is not received, quality indicator bits are generated based on the received signal quality for the power control bits received within a particular frame interval.

14. The method of claim 13, wherein the forward channel IS a forward fundamental channel (F-FCH) or a forward dedicated control channel (F-DCCH) defined by IS-2000.

15. The method of claim 13 wherein generating quality indicator bits based on received signal quality for power control bits comprises

Comparing the received signal quality for the power control bits to a threshold, and

setting the quality indicator bit based on the result of the comparison.

16. The method of claim 15, further comprising:

the threshold is updated based on a target received signal quality of the forward channel if a complete data frame is received.

17. The method of claim 15, wherein the threshold is initialized to a value derived based on a minimum required received signal quality for the forward channel.

18. A memory communicatively coupled to a Digital Signal Processing Device (DSPD) capable of interpreting digital information to:

determining whether a complete data frame is received from the first discontinuous transmission at a particular time interval;

generating quality indicator bits based on the complete data frame, if received; and

if a complete data frame is not received, a quality indicator bit is generated based on the second transmission.

19. A receiver unit in a wireless communication system, comprising:

an RX data processor operable to determine whether a complete data frame was received from a first discontinuous transmission at a particular time interval;

a signal quality measurement unit operable to determine a received signal quality of a second transmission within the particular time interval; and

a generator operable to generate a quality indicator bit based on the data frame when received in its entirety or based on the received signal quality of the second transmission when not received in its entirety.

20. The receiver unit of claim 19, wherein the signal quality measurement unit is operable to determine a received signal quality for power control bits received within a particular time interval.

21. A terminal, comprising:

an RX data processor operable to determine whether a complete data frame has been received from a first discontinuous transmission within a particular time interval;

a signal quality measurement unit operable to determine a received signal quality of a second transmission within the particular time interval; and

a generator operable to generate a quality indicator bit based on the data frame when received in its entirety or based on the received signal quality of the second transmission when not received in its entirety.

22. An apparatus in a wireless communication system, comprising:

means for determining whether a complete data frame is received from a first transmission within a particular time interval;

means for generating a quality indicator bit based on a complete data frame if the frame is received; and

means for generating a quality indicator bit based on the second transmission if a complete data frame is not received.