HK1180845B

HK1180845B - Radio base station and user equipment and methods therein

Info

Publication number: HK1180845B
Application number: HK13107777.9A
Authority: HK
Inventors: Robert Baldemair; David Astely; Dirk Gerstenberger; Daniel Larsson; Stefan Parkvall
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2010-01-18
Filing date: 2011-01-18
Publication date: 2016-08-05

Description

Radio base station and user equipment and methods therein

Technical Field

Embodiments herein relate to a radio base station, a user equipment and methods therein. In particular, embodiments herein relate to transmitting uplink control information contained in a bit block to a radio base station over a radio channel.

Background

Several different technologies are used in today's radio communication networks, such as Long Term Evolution (LTE), LTE-advanced, third generation partnership project (3GPP) Wideband Code Division Multiple Access (WCDMA), enhanced data rates for global system for mobile communications/GSM evolution (GSM/EDGE), worldwide interoperability for microwave access (WiMax), and Ultra Mobile Broadband (UMB), to name just a few.

Long Term Evolution (LTE) is an item within the third generation partnership project (3GPP) to evolve the WCDMA standard towards fourth generation mobile telecommunications networks. LTE provides increased capacity, higher data peak rates, and significantly improved latency compared to WCDMA. For example, the LTE specification supports downlink peak data rates of up to 300Mbp, uplink peak data rates of up to 75Mb/s, and radio access network round trip times of less than 10 ms. Furthermore, LTE supports carrier bandwidths that can be scaled down from 20MHz to 1.4MHz, and supports Frequency Division Duplex (FDD) and Time Division Duplex (TDD) operation.

LTE is a frequency division multiplexing technique in which Orthogonal Frequency Division Multiplexing (OFDM) is used in Downlink (DL) transmissions from a radio base station to user equipment. Single carrier-frequency domain multiple access (SC-FDMA) is used in Uplink (UL) transmission from a user equipment to a radio base station. Services in LTE are supported in the packet switched domain. SC-FDMA used in the uplink is also called Discrete Fourier Transform Spread (DFTS) -OFDM.

The basic LTE downlink physical resource can thus be seen as a time-frequency grid as illustrated in fig. 1, where each Resource Element (RE) corresponds to one OFDM subcarrier during one OFDM symbol interval. The symbol interval includes a cyclic prefix (cp), which cp is the prefix of the symbol with repetition of the symbol end to act as a guard band between symbols and/or to facilitate frequency domain processing. The frequency f or subcarriers with subcarrier spacing Δ f are defined along the z-axis and the symbol is defined along the x-axis.

In the time domain, the LTE downlink transmissions are organized into 10ms radio frames, each radio frame comprising 10 equally sized subframes #0- #9, each subframe having T_subframeA time length of =1ms, as shown in fig. 2. Furthermore, the resource allocation in LTE is typically described in terms of resource blocks, where a resource block corresponds to one slot of 0.5ms in the time domain and to 12 subcarriers in the frequency domain. The resource blocks are numbered in the frequency domain, starting from resource block 0 from one end of the system bandwidth.

Downlink transmissions are dynamically scheduled, i.e. in each subframe the base station or radio base station transmits control information in the current downlink subframe as to which user equipments or terminals data is to be transmitted and on which resource blocks data is to be transmitted. This control signaling is typically transmitted in the first 1, 2, 3, or 4 OFDM symbols in each subframe. A downlink system in which 3 OFDM symbols are used for control signaling is illustrated in fig. 3 and denoted as a control region. The resource units for control signaling are indicated by wavy lines, while the resource units for reference symbols are indicated by diagonal lines. The frequency f, or subcarrier, is defined along the z-axis and the symbol is defined along the x-axis.

LTE uses hybrid automatic repeat request (ARQ), where after receiving downlink data in a subframe, the user equipment attempts to decode it and reports to the radio base station whether the decoding was successful or not using uplink control signaling by sending an Acknowledgement (ACK) in case of successful decoding or a "negative acknowledgement" (NACK) in case of unsuccessful decoding. In case of an unsuccessful decoding attempt, the radio base station may retransmit the erroneous data.

Uplink control signalling from a user equipment or terminal to a base station or radio base station comprises

● hybrid ARQ acknowledgement for received downlink data;

● relates to user equipment or terminal reporting of downlink channel conditions, used as an aid to downlink scheduling;

● scheduling request, indicating that the user equipment or terminal needs uplink resources for uplink data transmission.

The uplink control information may be transmitted in two different ways:

● on the Physical Uplink Shared Channel (PUSCH). Uplink control information containing a hybrid ARQ acknowledgement is transmitted on the PUSCH with data if the user equipment or terminal has been assigned resources for data transmission in the current subframe.

● on the Physical Uplink Control Channel (PUCCH). If a user equipment or terminal has not been assigned resources for data transmission in the current subframe, uplink control information is transmitted on the PUCCH separately using resource blocks specifically assigned for that purpose.

Herein, the latter case is emphasized, i.e. layer 1/layer 2(L1/L2) control information exemplified by channel state reports, hybrid ARQ acknowledgements and scheduling requests is transmitted on the Physical Uplink Control Channel (PUCCH) in uplink resources, i.e. in resource blocks specifically assigned for uplink L1/L2 control information. Layer 1 includes the physical layer and layer 2 includes the data link layer. As illustrated in fig. 4, the PUCCH resources 41, 42 are located at the edge of the total available cell uplink system bandwidth. Each such resource comprises 12 "subcarriers", i.e. it comprises one resource block in each of the two slots of the uplink subframe. To provide frequency diversity, these frequency resources are frequency hopping on a narrow slot boundary, as illustrated by the arrows, i.e. within a subframe there is one "resource" 41 comprising 12 sub-carriers in the upper part of the spectrum in the first slot of the subframe and resources 42 comprising equal size in the lower part of the spectrum during the second slot of the subframe, or vice versa. If more resources are needed for uplink L1/L2 control signaling, e.g., in the case of a very large overall transmission bandwidth supporting a large number of users, additional resource blocks may be assigned immediately after the previously assigned resource block. The frequency f, or subcarrier, is defined along the z-axis and the symbol is defined along the x-axis.

The reason for locating the PUCCH resources at the edge of the total available spectrum is:

● together with the above-described frequency hopping, locating the PUCCH resources at the edge of the overall available spectrum maximizes the frequency diversity experienced by the control signaling.

● assigning uplink resources for the PUCCH elsewhere within the spectrum, i.e. not at the edge, will fragment the uplink spectrum, making it impossible: a very wide transmission bandwidth is assigned to a single mobile user equipment or terminal and still preserve the single carrier property of the uplink.

The bandwidth of one resource block during one subframe is too large for the control signaling needs of a single user equipment or terminal. Thus, in order to efficiently utilize the set of resources left for control signaling, multiple user equipments or terminals may share the same resource block. This is done by assigning different user equipments or terminals different orthogonal phase rotations of the frequency domain sequence of cell specific length 12.

The resources used by the PUCCH are therefore specified not only by the resource block pair in the time-frequency domain, but also by the applied phase rotation. Similar to the case of the reference signal, up to 12 different phase rotations are specified, providing up to 12 different orthogonal sequences from each cell specific sequence. However, in the case of frequency selective channels, not all 12 phase rotations can be used if orthogonality is to be preserved. Typically, up to 6 rotations may be considered for use in a cell.

As mentioned above, the uplink L1/L2 control signaling contains hybrid ARQ acknowledgements, channel state reports and scheduling requests. Different combinations of these types of messages are possible using one of the two available PUCCH formats that can carry different numbers of bits.

PUCCH format 1. There are actually three formats in the LTE specification, 1a and 1b, but they are all referred to herein as format 1 for simplicity. PUCCH format 1 is used for hybrid ARQ acknowledgements and scheduling requests. It can carry up to 2 information bits in addition to Discontinuous Transmission (DTX). If no information transfer is detected in the downlink, no acknowledgement, also called DTX, is generated. Thus, there are 3 or 5 different combinations depending on whether MIMO is used on the downlink. This is illustrated in fig. 5. The combination index is indicated in column 51, ARQ information sent when MIMO is not used is disclosed in column 52, and ARQ information when a first transport block and a second transport block are received when MIMO is used is shown in column 53.

PUCCH format 1 uses the same structure in both slots of a subframe, as illustrated in fig. 6. For transmission of a hybrid ARQ Acknowledgement (ACK), a Binary Phase Shift Keying (BPSK) symbol is generated using a single hybrid ARQ acknowledgement bit, and a Quadrature Phase Shift Keying (QPSK) symbol is generated using two acknowledgement bits in case of downlink spatial multiplexing. On the other hand, for scheduling requests, the BPSK/QPSK symbols are replaced by constellation points considered negative acknowledgements at the radio base station or evolved nodeb (enodeb). Each BPSK/QPSK symbol is multiplied by a length-12 phase-rotated sequence. They are then weighted with length 4 sequences before being transformed in the IFFT process. The phase shift varies at the SC-FDMA or DFTS-OFDM symbol level. The Reference Symbols (RS) are weighted with a length 3 sequence. The modulation symbols are then used to generate a signal to be transmitted in each of the two PUCCH slots. BPSK modulation symbols, QPSK modulation symbols, and complex-valued modulation symbols are examples of modulation symbols.

For PUCCH format 2, there are also three variants in the LTE specification, formats 2, 2a and 2b, with the latter two formats being used for simultaneous transmission of hybrid ARQ acknowledgements, as discussed later in this section. However, for simplicity, they are all referred to herein as Format 2.

The channel state report is used to provide the radio base station or eNodeB with an estimate of the channel properties at the user equipment or terminal in order to assist the channel dependent scheduling. The channel state report includes multiple bits per subframe. PUCCH format 1 (which can be up to two bits of information per subframe) clearly cannot be used for this purpose. Transmitting channel state reports on PUCCH instead is handled by PUCCH format 2, which is capable of multiple information bits per subframe.

PUCCH format 2, illustrated for the normal cyclic prefix in fig. 7, is based on the same phase rotation of the cell-specific sequence as format 1, i.e., a phase-rotated sequence of length 12 that varies in accordance with SC-FDMA or DFTS-OFDM symbols. The information bits are block coded, QPSK modulated, each QPSK symbol b0-b9 from the coding is multiplied by a phase rotated length-12 sequence, and all SC-FDMA or DFTS-OFDM symbols are finally IFFT processed before transmission.

To meet the upcoming International Mobile Telecommunications (IMT) -advanced requirements, 3GPP is currently standardizing LTE release 10, also referred to as LTE-advanced. One attribute of release 10 is to support bandwidths greater than 20MHz while still providing backward compatibility with release 8. This is achieved by aggregating multiple component carriers, where each component carrier may be release 8 compatible to form a larger total bandwidth to release 10 user equipment. This is illustrated in fig. 8, where 5 20MHz are aggregated to 100 MHz.

Essentially, each component carrier in fig. 8 is processed separately. For example, hybrid ARQ operates separately on each component carrier, as illustrated in fig. 9. For hybrid ARQ operation, an acknowledgement is needed that informs the transmitter whether the reception of the transport block was successful. A straightforward way to achieve this is to transmit multiple acknowledgement messages, one for each component carrier. In the spatial multiplexing case, the acknowledgement message will correspond to two bits, since in the first release of LTE there are already two transport blocks on the component carrier in this case. Without spatial multiplexing, the acknowledgement message is a single bit, since there is only a single transport block per component carrier. Each flow F1-Fi illustrates a data flow to the same user. Radio Link Control (RLC) is performed on the RLC layer for each received data flow. In a Medium Access Control (MAC) layer, MAC multiplexing and HARQ processes are performed on a data stream. In the Physical (PHY) layer, encoding and OFDM modulation of a data stream are performed.

Transmitting multiple hybrid ARQ acknowledgement messages, one per component carrier, may be cumbersome in some situations. Using PUCCH format 1 may send back at most two bits of information to the radio base station or eNodeB if the current LTE Frequency Division Multiplexing (FDM) uplink control signaling structure is to be reused.

One possibility is to bundle multiple acknowledgement bits into a single message. For example, an ACK may be signaled only if all transport blocks on all component carriers are correctly received in a given subframe, otherwise a NACK is fed back. This has the disadvantage that even if some transport blocks are correctly received, they may be retransmitted, which may reduce system performance.

Introducing a multi-bit hybrid ARQ acknowledgement format is an alternative solution. However, in the case of multiple downlink component carriers, the number of acknowledgement bits in the uplink may become quite large. For example, for 5 component carriers, each using MIMO, there are 5⁵Different combinations, bearing in mind that DTX is preferably also taken into account, at leastA bit. This situation may become worse in Time Division Duplex (TDD), where multiple downlink subframes may need to be acknowledged in a single uplink subframe. For example, in a TDD configuration with 4 downlink subframes and 1 uplink subframe every 5ms, there are 5^5.4A combination corresponding to more bits than 46 bits of information.

Currently, there is no PUCCH format capable of carrying such a large number of bits in the prescribed LTE. US2008/247477 a1 relates to the following systems: wherein the samples within the DFTS-OFDM symbol are scaled by a scaling factor.

Disclosure of Invention

It is an object of embodiments herein to provide mechanisms for achieving high transfer performance in a radio communication network in an efficient manner. This object is achieved by a method and an apparatus according to claims 1, 7, 8, 14, 15.

According to a first aspect of embodiments herein, the object is achieved by a method in a user equipment for transmitting uplink control information to a radio base station over a radio channel in a time slot in a subframe. The radio channel is arranged to carry uplink control information and the user equipment and the radio base station are comprised in a radio communications network. The uplink control information is contained in a bit block.

The user equipment maps the block of bits to a sequence of complex-valued modulation symbols. The user equipment also block spreads the sequence of complex valued modulation symbols over discrete fourier transform spread-orthogonal frequency division multiplexing (DFTS-OFDM) symbols. This is performed by applying a spreading sequence to the sequence of complex valued modulation symbols to achieve a block spread sequence of complex valued modulation symbols. The user equipment also transforms the block-spread sequence of complex-valued modulation symbols in accordance with the DFTS-OFDM symbols. This is performed by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the block-spread sequence of complex-valued modulation symbols. The user equipment also transmits the block spread sequence of complex valued modulation symbols that has been transformed to the radio base station over a radio channel.

According to another aspect of embodiments herein, the object is achieved by a user equipment for transmitting uplink control information to a radio base station over a radio channel in a time slot in a subframe. The radio channel is arranged to carry uplink control information and the uplink control information is contained in a bit block.

The user equipment comprises a mapping circuit configured to map a block of bits to a sequence of complex valued modulation symbols. In addition, the user equipment includes: a block spreading circuit configured to block spread the sequence of complex valued modulation symbols over the DFTS-OFDM symbol by applying a spreading sequence to the sequence of complex valued modulation symbols to achieve a block spread sequence of complex valued modulation symbols. Further, the user equipment comprises a transform circuit configured to transform the block spread sequence of complex valued modulation symbols in accordance with the DFTS-OFDM symbols. This is done by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the block-spread sequence of complex-valued modulation symbols. The user equipment further comprises a transmitter configured to transmit the block-spread sequence of transformed complex-valued modulation symbols over a radio channel to a radio base station.

According to another aspect of embodiments herein, the object is achieved by a method in a radio base station for receiving uplink control information from a user equipment in a slot in a subframe over a radio channel. The radio channel is arranged to carry uplink control information and the uplink control information is contained in a bit block. The user equipment and the radio base station are comprised in a radio communication network.

A radio base station receives a sequence of complex-valued modulation symbols. The radio base station also performs OFDM demodulation on the complex-valued modulation symbol sequence. The radio base station also transforms the complex-valued modulation symbol sequence that has been OFDM-demodulated in accordance with the DFTS-OFDM symbol by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the complex-valued modulation symbol sequence that has been OFDM-demodulated.

The radio base station also despreads the complex-valued modulation symbol sequence that has been OFDM-demodulated and transformed with a despreading sequence. The radio base station also maps the despread sequences of complex-valued modulation symbols that have been OFDM-demodulated and transformed to a block of bits.

According to another aspect of embodiments herein, the object is achieved by a radio base station for receiving uplink control information from a user equipment over a radio channel in a slot in a subframe. The radio channel is arranged to carry uplink control information and the uplink control information is contained in a bit block. The radio base station comprises a receiver configured to receive a sequence of complex-valued modulation symbols. The radio base station further comprises an OFDM demodulation circuit configured to OFDM demodulate the sequence of complex-valued modulation symbols. The radio base station further comprises a transformation circuit configured to transform the complex-valued modulation symbol sequence that has been OFDM-demodulated in accordance with the DFTS-OFDM symbol by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the complex-valued modulation symbol sequence that has been OFDM-demodulated. The radio base station further comprises a block despreading circuit configured to block despread the complex valued modulation symbol sequence that has been OFDM demodulated and transformed with a despreading sequence. Furthermore, the radio base station comprises a mapping circuit configured to map a despread sequence of complex-valued modulation symbols that have been OFDM-demodulated and transformed to a block of bits.

Thereby, inter-cell interference is reduced, since the one or more matrices transform the block spread sequence of complex valued modulation symbols in accordance with the DFTS-OFDM symbols, and thereby increase interference suppression.

According to another aspect of embodiments herein, the object is achieved by a method in a terminal for transmitting uplink control information in a slot in a subframe over a channel to a base station in a wireless communication system. The uplink control information is contained in a codeword. The terminal maps the codeword to a modulation symbol. The terminal block spreads the modulation symbols over the DFTS-OFDM symbols by repeating the modulation symbols for each DFTS-OFDM symbol and applying a block spreading sequence of weighting factors to the repeated modulation symbols to achieve a respective weighted copy of the modulation symbols for each DFTS-OFDM symbol. The terminal then transforms the respective weighted copy of the modulation symbols for each DFTS-OFDM symbol by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the respective weighted copy of the modulation symbols. The terminal then transmits a respective weighted copy of the transformed modulation symbols to the base station on or within each DFTS-OFDM symbol.

In some embodiments herein, a transport format is provided in which blocks of codewords or bits corresponding to uplink control information from all configured or activated component carriers of a single user are mapped to modulation symbols, such as a sequence of complex valued modulation symbols, and block spread over DFTS-OFDM symbols using a spreading sequence. The sequence of symbols within one DFTS-OFDM symbol is then transformed and transmitted within one DFTS-OFDM symbol. User multiplexing is achieved with block spreading, i.e. the same signal or symbol sequence is spread over all DFTS-OFDM symbols within one slot or subframe and inter-cell interference is reduced according to the transform of the DFTS-OFDM symbols.

Drawings

Embodiments will now be described in more detail with respect to the accompanying drawings, in which:

FIG. 1 is a block diagram depicting resources in a frequency-time grid;

fig. 2 is a block diagram depicting an LTE time domain structure of a radio frame;

fig. 3 is a block diagram depicting symbols distributed over a downlink subframe;

FIG. 4 is a block diagram depicting uplink L1/L2 control signaling on PUCCH;

fig. 5 is a table defining HARQ information combinations;

fig. 6 is a block diagram of PUCCH format 1 with normal-length cyclic prefix;

fig. 7 is a block diagram of PUCCH format 2 with a normal-length cyclic prefix;

fig. 8 is a block diagram depicting carrier aggregation;

FIG. 9 is a block diagram depicting RLC/MAC and PHY layers for carrier aggregation;

fig. 10 is a block diagram depicting a radio communications network;

FIG. 11 is a block diagram depicting a process in a user equipment;

FIG. 12 is a block diagram depicting a process in a user equipment;

FIG. 13 is a block diagram depicting a process in a user equipment;

FIG. 14 is a block diagram depicting a process in a user equipment;

FIG. 15 is a block diagram depicting a process in a user equipment;

FIG. 16 is a block diagram depicting a process in a user equipment;

FIG. 17 is a block diagram depicting a procedure in a user equipment;

FIG. 18 is a block diagram depicting a procedure in a user equipment;

FIG. 19 is a block diagram depicting a procedure in a user equipment;

FIG. 20 is a schematic flow chart diagram depicting a procedure in a user equipment;

FIG. 21 is a block diagram depicting a user device;

fig. 22 is a schematic flow chart of a procedure in a radio base station; and

fig. 23 is a block diagram depicting a radio base station.

Detailed Description

Fig. 10 discloses an exemplary radio communication network, also referred to as a wireless communication system, according to a radio access technology such as Long Term Evolution (LTE), LTE-advanced third generation partnership project (3GPP) Wideband Code Division Multiple Access (WCDMA), enhanced data rates for global system for mobile communication/GSM evolution (GSM/EDGE), worldwide interoperability for microwave access (WiMax) or Ultra Mobile Broadband (UMB), to mention just a few possible implementations.

The radio communication network comprises user equipment 10, also referred to as terminal 10, and radio base stations 12. The radio base station 12 serves the user equipment 10 in the cell 14 by providing radio coverage over a geographical area. The radio base station 12 transmits data to the user equipment 10 in Downlink (DL) transmission, and the user equipment 10 transmits data to the radio base station 12 in Uplink (UL) transmission. The UL transmission may be efficiently generated at the user equipment 10 by using an inverse fourier transform (IFFT) process and then demodulated at the radio base station 12 by using a Fast Fourier Transform (FFT) process.

It should be noted here that the radio base station 12 may also be referred to as e.g. NodeB, evolved NodeB, (eNB, eNodeB), base station, base transceiver station, access point base station, base station router, or any other network element capable of communicating with user terminals within the cell served by the radio base station 12, e.g. according to the radio access technology and terminology used. The user equipment 10 may be represented by a terminal, such as a wireless communication user equipment, a mobile cellular phone, a Personal Digital Assistant (PDA), a wireless platform, a desktop computer, a computer or any other kind of device capable of communicating wirelessly with the radio base station 12.

The radio base station 12 transmits control information about to which user equipment data is to be transmitted and on which resource blocks the data is transmitted. The user equipment 10 attempts to decode the control information and data and reports to the radio base station 12 using uplink control signalling whether the decoding of the data was successful or unsuccessful, transmitting an Acknowledgement (ACK) in case of success and a negative acknowledgement (NACK, NAK) in case of non-success.

According to embodiments herein, the user equipment 10 is arranged to transmit a block of bits corresponding to uplink control information to the radio base station 12 over a channel (i.e. a radio channel) in a slot (i.e. a time slot) in a subframe. The bit block may include jointly coded ACKs and/or NACKs. The channel may be a Physical Uplink Control Channel (PUCCH), which is a radio channel arranged to carry uplink control information. The bit block may also be referred to as a number of bits, a codeword, coded bits, information bits, an ACK/NACK sequence, or the like.

The user equipment 10 maps the bit block to a modulation symbol, i.e. a complex valued modulation symbol sequence. This mapping may be a QPSK mapping, wherein the resulting QPSK modulation symbols are complex valued, wherein one of the two bits in each QPSK modulation symbol represents the real part of the modulation symbol, also referred to as the I channel, and the other bit is the imaginary part of the modulation symbol, also referred to as the Q channel. The modulation symbols may be referred to as complex-valued modulation symbols, QPSK symbols, BPSK symbols, or the like.

The user equipment 10 then block spreads the sequence of complex-valued modulation symbols with a spreading sequence, such as an orthogonal sequence. For example, the same signal or bit block that has been mapped to complex-valued modulation symbols may be spread over all of the DFTS-OFDM symbols in the set of DFTS-OFDM symbols by applying a spreading sequence to the sequence of complex-valued modulation symbols representing the signal or bit block. The block-spread sequence of complex-valued modulation symbols may thus be divided into sections or segments, wherein each segment or section of the block-spread sequence of complex-valued modulation symbols corresponds to or is assigned to one DFTS-OFDM symbol out of the set of DFTS-OFDM symbols, i.e. there is a one-to-one correspondence between a segment or section and a DFTS-OFDM symbol. The DFTS-OFDM symbol is also referred to as an SC-FDMA symbol. SC-FDMA can be viewed as normal OFDM with DFT based precoding.

According to embodiments herein, the user equipment 10 then transforms or precodes the block-spread sequence of complex-valued modulation symbols in accordance with the DFTS-OFDM symbols with a matrix according to the DFTS-OFDM symbol index and/or the slot index. Thus, this segment or part of the block spread sequence of complex valued modulation symbols is transformed separately by applying a matrix to each segment or part of the block spread sequence of complex valued modulation symbols corresponding to or assigned to the DFTS-OFDM symbol. The matrix may be a general matrix including a DFT matrix (e.g., a cyclically shifted DFT matrix), wherein the amount of cyclic shift varies with the DFTs-OFDM symbol index and/or the slot index. By transforming the block-spread sequence of complex-valued modulation symbols in this manner, inter-cell interference is reduced. The time slot comprises a plurality of DFTS-OFDM symbols, i.e. each time slot is associated with a plurality of matrices, one for each DFTS-OFDM symbol. The slot index indicates a slot within which the one or more matrices are to be applied. The DFTS-OFDM symbol index indicates the DFTS-OFDM symbol and thus the segment or portion of the block spreading sequence to which the complex valued modulation symbols of the matrix are to be applied.

The user equipment 10 then transmits a block spread sequence of transformed complex valued modulation symbols. For example, the user equipment 10 may also OFDM modulate and transmit each transformed or precoded segment or portion of the block spreading sequence within the duration of one DFTS-OFDM symbol, i.e., the DFTS-OFDM symbol corresponds to a respective segment or portion of the block spreading sequence of complex valued modulation symbols. This process may be referred to as transform/precoded OFDM modulation.

In a variation of this embodiment, the sequence of complex-valued modulation symbols may be divided into a plurality of portions, and each portion of the sequence of complex-valued modulation symbols may be transmitted in a time slot.

Some embodiments herein may relate to ACK/NACK transmission on PUCCH in a radio communications network employing aggregation of multiple cells, i.e. component carriers, providing support for bandwidths larger than a single carrier while still providing backward compatibility with previous techniques. According to embodiments herein, in such a radio communication network, a PUCCH format capable of carrying a larger number of bits than provided by existing PUCCH formats is provided in order to enable ACK/NACK signaling for each of a plurality of component carriers.

Embodiments herein enable high payload PUCCH transmission required for such signaling by providing a block spread DFTS-OFDM transmission format. According to this format, all ACK/NACK information from all component carriers of a single user equipment are jointly encoded in a codeword. In some embodiments, this codeword of the bit block corresponding to the uplink control information may then be scrambled to mitigate inter-cell interference and mapped onto a sequence of symbols, such as complex-valued modulation symbols. Multiplexing of the user equipment is achieved with block spreading, i.e. spreading or repeating the same signal in the form of codewords, possibly scrambled with different sequences, or symbols if the codewords have been mapped to symbols before block spreading, over all DFTS-OFDM symbols of a slot or subframe, but weighting these symbols within the subframe or slot with different scalars or weighting factors from the spreading sequences of each DFTS-OFDM symbol. The symbol sequence for each DFTS-OFDM symbol is then transformed or precoded with a matrix (e.g., a modified precoding matrix) and transmitted for the duration of one DFTS-OFDM symbol. To mitigate interference even further, the matrix of the modified DFTS-OFDM modulator is modified in a pseudo-random manner, e.g. by permuting the matrix elements. The transformation or precoding may be a modified DFTS-OFDM modulation in which the DFT operation is combined with a cyclic shift operation or a scrambling operation.

Embodiments herein provide a format referred to as PUCCH format 3 that provides flexibility in that some solutions may be adapted to the ever increasing payload required for uplink control information. It also introduces means to improve inter-cell interference suppression. These means are any one or a combination of scrambling with scrambling codes, selection matrices, or cyclic shifting matrix elements with a cyclic shift pattern. The scrambling code and/or cyclic shift pattern may be selected in a random manner according to the cell ID and/or DFTS-OFDM symbol/slot/subframe/radio frame number in order to randomize the inter-cell interference. Furthermore, the format or structure allows for a trade-off (trade) of payload and/or coding gain and/or inter-cell interference suppression (for multiplexing capacity). A low code rate refers to a number of coded bits related to the information bits, and if the coded bits are scrambled, the longer the scrambling sequence, the better the inter-cell interference suppression. The length of the spreading sequence determines the multiplexing capacity.

Fig. 11 depicts, together with fig. 12, one embodiment of a process for block spreading a sequence of complex valued modulation symbols in a user equipment 10. Fig. 11 shows how an ACK/NACK sequence a, which is an example of a bit block corresponding to uplink control information, is transmitted within one DFTS-OFDM symbol. Sequence a represents the ACK/NACK from all aggregated component carriers. Alternatively, each bit may also represent a logical and connection of each ACK/NACK bit. This sequence a may not only represent an ACK/NACK, but may also encode a Discontinuous Transmission (DTX) status (e.g., if no scheduling assignment is received for certain component carriers).

In a first step, the sequence a may be encoded in an error correction coding module 111 to make it more robust against transmission errors. The error correction coding scheme used may be a block code, a convolutional code, etc. It is possible that the error correction coding module 111 may also include interleaving functionality that sets the bit blocks so that errors may occur in a more evenly distributed manner, thereby improving performance.

To randomize neighbor cell interference, cell-specific scrambling with code c may be applied in the scrambling module, resulting in a scrambling sequence, i.e., a block of scrambled bits. The scrambled sequence is then mapped to modulation symbols in a symbol mapping module 112, e.g. using QPSK, resulting in a complex valued modulation symbol sequence x, and modulated and transmitted with a DFTS-OFDM modulator 113 resulting in a symbol sequence v for transmission. The sequence v is a digital signal so it can be fed into a digital-to-analog converter, modulated to radio frequency, amplified, fed into an antenna and then transmitted.

The DFTS-OFDM modulator 113 is a modified DFTS-OFDM modulator including a matrix G114, and may further include an IFFT module 115 and a cyclic prefix generator 116. Thus, the sequence v is transmitted over a DFTS-OFDM symbol or within a DFTS-OFDM symbol duration. However, in order to enable different users or user equipments to be multiplexed, the bit block is to be transmitted to the radio base station 12 over multiple DFTS-OFDM symbols. The matrix G114 includes matrix elements, and the matrix may correspond to a DFT operation along with a cyclic shift operation of a row or column of a matrix unit, or to a DFT operation along with a scrambling operation of a matrix unit.

For example, the symbol mapping module 112 maps a block of bits onto a sequence of complex-valued modulation symbols x. Block spreading sequence for obtaining complex valued modulation symbols after block spreadingWhereinIs a spreading sequence of scalar or weighting factors, which in some embodiments may comprise orthogonal sequences. And then for each weighted copy or instance of the modulation symbolThe modified DFTS-OFDM modulation is performed separately. Also transmitted separately, e.g. performed、And the like. Thus, precoding and transmission can be performed such thatIn aOne weighted copy or instance of the modulation symbol per DFTS-OFDM symbolPrecoding and transmitting are performed, where K is the number of DFTS-OFDM symbols over which the modulation symbols can be block spread. The spreading sequences, e.g., orthogonal sequences, provide separation between user equipments or, more specifically, between uplink transmissions by different user equipments.

It should also be understood that if no frequency hopping is applied, the solution outlined above applies to the sub-frame, with the parameters adjusted accordingly. The number of available DFTS-OFDM symbols may be 12 in this case (assuming 2 DFTS-OFDM symbols are reserved for reference signals).

If frequency hopping is enabled, the solution outlined above can be used for each slot, possibly with a different scrambling code and spreading sequence. In this case, the same payload would be transmitted in both slots. Alternatively, the scrambling sequence or modulation symbols (i.e., the sequence of complex valued modulation symbols) is split into two parts, with the first part being transmitted in a first time slot and the second part being transmitted in a second time slot. In principle, even the bit block a may be divided and the first part may be transmitted in the first time slot and the second part may be transmitted in the second time slot. However, this is less preferred because in this case the block of bits processed and transmitted in each time slot is small, e.g. half the size before the division, resulting in a reduced coding gain.

Fig. 12 shows an embodiment in which blocks of signals or bits are spread. The processing chain includes an error correction coding block module 111. In the simplest case, the same signal or bit block is block spread, i.e. repeated a number of times, and mapped to a modulation symbol, i.e. a sequence of complex valued modulation symbols, and each copy or instance of a modulation symbol is represented by a scalar quantityWeights, which are also referred to as weighting factors from the spreading sequence. It should be noted thatThe firing may occur before the block expansion. If we haveKOne DFTS-OFDM symbol, the spreading sequence has a length K, i.e.. K orthogonal spreading sequences can then be constructed and K users can thus be multiplexed. Thus, the K orthogonal sequences are used in block spreading of modulation symbols, i.e. in complex valued modulation symbol sequences. This is illustrated in FIG. 12, where each of the labels is labeledIncludes the module 112 according to fig. 11 and 116. An equivalent implementation allows for the application of weighting factors anywhere else after the symbol mapping module 112 as illustrated in fig. 12, where the weighting factors areK-1 is applied to the corresponding v sequence behind the DFTS-OFDM modulator 113 of the corresponding process chain for DFTS-OFDM symbol 0. In addition, it is equivalent to first mapping the bit block to a modulation symbol, e.g., a complex valued modulation symbol, and then repeating the modulation symbol and resetting the block, and then mapping each repeated bit block to a modulation symbol.

In an alternative arrangement, if the symbol scaling w K is omitted, the signal or block of bits conveyed in the K DFTS-OFDM symbols is not a copy, but each block Mod1-ModK in fig. 12 actually performs scrambling with a different scrambling sequence. Otherwise, FIG. 11 is still valid. In this case, the respective scrambling sequences may be according to DFTS-OFDM symbols/slots/subframes/radio frame numbers in addition to the cell IDs. The scrambling, and in particular the scrambling sequence, may provide better randomization of inter-cell interference and mitigation than prior art DFTS-OFDM PUCCH transmissions, in terms of cell ID and/or DFTS-OFDM/slot/subframe/radio frame number.

For example, assuming one reference symbol per slot, also referred to as a reference signal, K may be 6 (assuming a normal cyclic prefix in LTE). Alternatively, if frequency hopping is not used, K may be 12 (assuming one reference signal per slot). The exact design of the reference signal is not discussed further.

Depending on the number of allocated resource blocks in the DFTS-OFDM modulator 113, the number of coded bits can be controlled, thereby also the code rate and/or the payload size, the ACK/NACK sequence or the length of the bit block a. For example, if only a single resource block is allocated in the frequency domain, 24 coded bits are available per DFTS-OFDM symbol (assuming QPSK symbol). If this is not sufficient, the number of allocated resource blocks may be increased. The more coded bits, the longer the scrambling code c is allowed, and the higher the resulting scrambling gain.

It is worth doing that the proposed scheme allows multiplexing users with different resource block allocations. In fig. 13, an example is provided in which 3 user equipments are multiplexed. The first user equipment 10 needs a higher ACK/NACK payload and therefore occupies 2 resource blocks. For the remaining two user equipments, one resource block each is sufficient, and these are Frequency Division Multiplexed (FDM). Since these user equipments are FDM multiplexed, they can reuse the same spreading sequence, but of course they can use different spreading sequences. In this example, the spreading factor is 4. The user equipment 10, which is allocated 2 resource blocks, uses the spreading codes 1-11-1 to obtain a block spreading sequence of complex valued modulation symbols over the DFTS-OFDM symbols denoted 121 and 124. The remaining user equipments use spreading codes 1111 to obtain a block spread sequence of complex valued modulation symbols over DFTS-OFDM symbols denoted 131-.

Fig. 14 is a block diagram depicting a processing chain, such as a transmitter in the user equipment 10, for transmitting uplink control information for one DFTS-OFDM symbol, in accordance with an embodiment. The user equipment 10 may comprise an error correction coding module 111, wherein the bit block a may be coded to make it more robust against transmission errors. To randomize neighbor cell interference, cell specific scrambling with code c may be applied, resulting in a scrambled sequence. The scrambled sequence may then be mapped onto modulation symbols, i.e., a sequence of complex-valued modulation symbols, in a symbol mapping module 112, and then block-spread with a spreading sequence (not shown). The user equipment 10 transforms (e.g., precodes) the block spread sequence of complex valued modulation symbols in DFTS-OFDM symbols in a DFTS-OFDM modulator 113 with a matrix G114 according to the DFTS-OFDM symbol index and/or slot index. In the illustrated example, the matrix G114 corresponds to a Discrete Fourier Transform (DFT) operation 141 along with a row or column cyclic shift operation 142. The user equipment 10 may further include an IFFT module 115 and a cyclic prefix generator 116. Thus, the spreading sequence of blocks of complex valued modulation symbols is modulated and transmitted over a DFTS-OFDM symbol or within one DFTS-OFDM symbol duration. However, in order to enable different users to be multiplexed, the error correction coded bit block is to be transmitted over a plurality of DFTS-OFDM symbols to the radio base station 12.

A variant of the above embodiment is that the scrambling sequence is not mapped onto one DFTS-OFDM symbol but onto a plurality of DFTS-OFDM symbols. Fig. 15 shows an example in which the scrambled bit block s is transmitted over 2 DFTS-OFDM symbols or over the duration of two DFTS-OFDM symbols. In this example, a 48-bit long scrambling sequence or block of bits s is mapped to 24=2x12 QPSK symbols and transmitted in 2 DFTS-OFDM symbols (assuming one resource block allocation and 12 symbols carried per DFTS-OFDM symbol). The block of bits a may be processed in an error correction coding module 151, which error correction coding module 151 may correspond to the error correction coding module 111 in fig. 11. To randomize neighbor cell interference, cell-specific scrambling with code c in bit scrambling module 152 may be applied, resulting in a scrambling sequence s, i.e., a block of scrambled bits. Spreading the scrambling sequence s over two different DFTS-OFDM symbols or splitting the scrambling sequence s over two different DFTS-OFDM symbols. The first half of s is then mapped to symbols (e.g., using QPSK) in a first symbol mapping module 153 and modulated and transmitted with a first modified DFTS-OFDM modulator. The first modified DFTS-OFDM modulator includes a first precoding matrix G154, and may further include a first IFFT module 155 and a first cyclic prefix generator 156.

The second half of s is then mapped to symbols (e.g., using QPSK), e.g., to complex-valued modulation symbols, and modulated and transmitted with a second modified DFTS-OFDM modulator in a second symbol mapping module 153'. The second modified DFTS-OFDM modulator includes a second precoding matrix G154 ', and may also include a second IFFT module 155' and a second cyclic prefix generator 156 '.

Thus, a first half of the bit block is transmitted on a first DFTS-OFDM symbol and a second half of the bit block is transmitted on a second DFTS-OFDM symbol. However, in order to enable different users to be multiplexed, the error correction coded block of scrambled bits s is to be transmitted over a plurality of DFTS-OFDM symbols to the radio base station 12.

An embodiment of a correspondingly modified block expansion process is depicted in fig. 16. In this example, the block spreading is shown for the case where the block of scrambled bits s is transmitted over 2 DFTS-OFDM symbols. Each block "Mod" comprises the arrangement shown in fig. 15, not comprising error correction coding functionality. This variation achieves higher payload and scrambling gain than the baseline case of fig. 11. However, the price paid is reduced multiplexing capacity. If we assume that K DFTS-OFDM symbols are available for transmission and use one instance of L of them for scrambling the bit block, the length of the spreading code or spreading sequence-and thus also the multiplexing capacity-is reduced to K/L. In this example, the multiplexing capacity is reduced by a factor of two compared to the case when the scrambled bit block s is modulated and transmitted on one DFTS-OFDM symbol. The bit block corresponding to the uplink information, such as ACK/NACK, is processed in an error correction coding module 161, which error correction coding module 161 may correspond to the error correction coding module 111 in fig. 11. The modules Mod1-ModK/2 in FIG. 16 perform scrambling with different scrambling sequences, wherein the weighting factors are assignedThe respective block spreading modulation symbols are applied, i.e. are followed by a module Mod-ModK/2 by a respective block spreading sequence of complex valued modulation symbols.

In another embodiment, the order in which the scrambling operation and symbol mapping are performed is changed according to fig. 17. Here, scrambling is applied at the symbol level instead of the bit level, which means that symbol mapping is performed before symbol scrambling. Scrambling codeMay be based on the cell ID and DFTS-OFDM symbol index/slot/subframe/radio frame number. The user equipment 10 may herein comprise an error correction coding module 171, wherein the sequence or bit block a may be coded to be more robust against transmission errors. The error correction encoding module 171 may correspond to the error correction encoding module 111 in fig. 11. The block of bits is then mapped to modulation symbols, i.e. a sequence of complex valued modulation symbols, in a symbol mapping module 172. To randomize neighbor cell interference, a used code may be applied to symbols in the symbol scrambling module 173Resulting in a scrambling sequence s'. The scrambled sequence is then discrete fourier transformed in DFT module 174. The symbol scrambling module 173 and the DFT module 174 may be included in the matrix G114. Thus, the user equipment 10 then transforms (e.g., precodes) the block spread modulation symbols, i.e., the block spread sequence of complex valued modulation symbols, in DFTS-OFDM symbols with a matrix G114 according to the DFTS-OFDM symbol index and/or slot index. The user equipment 10 may also include an IFFT module 175 and a cyclic prefix generator 176. Thus, the block spread modulation symbols, i.e. the block spread sequence of complex valued modulation symbols, are transmitted over a DFTS-OFDM symbol or within one DFTS-OFDM symbol duration. However, in order to enable different users to be multiplexed, the bit block is to be transmitted to the radio base station 12 over multiple DFTS-OFDM symbols.

The scrambling operation may be described mathematically in some embodiments by multiplying by a diagonal matrix C, the diagonal elements of which are determined by the scrambling codeWherein is formed byIs a scrambling sequence at the symbol level. The subsequent DFT operation may be described by DFT matrix F. Using this notation, the exemplary illustrations for these examples are combinedExample can be composed of a matrixAnd (4) showing. Scrambling and DFT operations may be performed in the matrix G. In this case, the block spreading is performed before the scrambling operation.

In fig. 18, a block diagram of embodiments herein is disclosed. The user equipment 10 may alternatively comprise an error correction coding module 181, wherein the sequence or bit block a may be coded to be more robust against transmission errors. The error correction encoding module 181 may correspond to the error correction encoding module 111 in fig. 11. To randomize neighbor cell interference, cell-specific scrambling with code c may be applied to the possible error correction coded bit blocks in the bit scrambling module 182. The scrambled block of bits s is then mapped to a sequence of complex valued modulation symbols in a symbol mapping module 183. The modulation symbols are block spread with a spreading sequence (not shown). The user equipment 10 then transforms (e.g., precodes) the block-spread sequence of complex-valued modulation symbols in DFTS-OFDM symbols with a matrix G114 according to the DFTS-OFDM symbol index and/or slot index. The user equipment 10 may also include an IFFT module 185 and a cyclic prefix generator 186. The block spread modulation symbols, i.e. the block spread sequence of complex valued modulation symbols, are modulated and transmitted over a DFTS-OFDM symbol or within one DFTS-OFDM symbol duration. However, in order to enable the users to be multiplexed, the scrambled bit block s is to be transmitted to the radio base station 12 over a plurality of DFTS-OFDM symbols.

Due to scrambling code correlation, the matrix G114 in the DFTS-OFDM modulator 113 may vary with cell ID and/or DFTS-OFDM symbol index/slot/subframe/radio frame number.

The matrix G may be the product of a diagonal matrix and a DFT matrix. However, instead of the product, we can assume a general matrix G. To randomize interference, the matrix G may be based on cell ID and/or DFTS-OFDM symbol index/slot/subframe/radio frame number. In order to be able to decode the transmission signal of the uplink control information at the receiver, the minimum requirement for G is the presence of its inverse matrix.

A simpler receiver can be constructed if the matrix G is orthogonal, since in this case its inverse is simply the hermitian transpose of the matrix G. Depending on the application, low envelope fluctuation, low cubic metric, or peak-to-average power ratio of the transmitted signal of uplink control information may be of interest. In this case, the combination of matrix G and the subsequent IFFT operation should result in a signal with a low cubic metric.

One such matrix would be a DFT matrix whose rows or columns are cyclically shifted, e.g., assuming M rows, row 1 becomes row n, row 2 becomes (n +1) mod M, and so on. This operation results in a cyclic shift of the subcarriers or mapped complex-valued modulation symbols, see fig. 14 for illustration. The cyclic shift amount or cyclic shift pattern may be according to a cell ID and/or a DFTS-OFDM symbol index/slot/subframe/radio frame number. Randomize and mitigate inter-cell interference according to cell ID and either DFTS-OFDM symbol index/slot/subframe/radio frame number cyclic shift subcarriers or complex valued modulation symbols. This improves inter-cell interference mitigation compared to prior art DFTS-OFDM PUCCH transmission. The DFT matrix may be the product of the DFT matrix and the diagonal scrambling matrix in some embodiments.

General permutations of rows or columns are also possible; however, in this case the stereo metric increases.

The techniques disclosed herein, for example, enable high payload PUCCH transmission in some embodiments. Furthermore, these techniques may also provide flexibility to adapt the solution to a desired payload. These techniques are also helpful because they introduce means to improve inter-cell interference. These means are scrambling with scrambling codes, selection of matrix G and/or cyclic shifting of matrix elements with a cyclic shift pattern. The scrambling code c or cyclic shift pattern may be selected in a pseudo-random manner to randomize the inter-cell interference according to the cell ID and/or DFTS-OFDM symbol/slot/subframe/radio frame number. Furthermore, embodiments herein allow for changing the structure of the PUCCH format to trade off payload and/or coding gain and/or inter-cell interference suppression (for multiplexing capacity).

FIG. 19 is a schematic block diagramAn embodiment of a transfer procedure in a user equipment 10 is depicted. The bit block corresponding to the uplink control information is to be transmitted to the radio base station 12 on a radio channel. For example, the number of HARQ feedback bits may be determined by the number of configured cells and the transmission mode (e.g., component carrier 1(CC1), CC3: MIMO, CC2: no MIMO). The bit block may be error correction encoded in a Forward Error Correction (FEC) module 191. Further, the error correction coded bit blocks may then be scrambled in a bit scrambling module 192, which bit scrambling module 192 may correspond to the bit scrambling module 182 in FIG. 18. The user equipment 10 also comprises several block modules Mod0-Mod 4. Each block module includes a bit-to-symbol mapping module in which a block of bits is mapped to a sequence of complex-valued modulation symbols. Furthermore, each block module Mod0-Mod4 comprises a block spreading module configured to block spread the complex-valued modulation symbol sequences together with a spreading sequence oc1-oc4, e.g. orthogonal covering to multiplex the user equipments. Within each block module, the block extensions are simply multiplied by oc_iI = 0.., 4. The block modules Mod0-Mod4 are used together with [ oc0, oc1, …, oc4]Block spreading is performed on the sequence of complex valued modulation symbols. In addition, the block-spread sequence of complex-valued modulation symbols is transformed according to the DFTS-OFDM symbol, i.e. by applying a matrix according to (i.e. varying with) the DFTS-OFDM symbol index and/or the slot index, each segment of the block-spread sequence of complex-valued modulation symbols is transformed. This may be performed by first cyclically shifting each segment of the block-spread sequence of complex-valued modulation symbols, thereby performing a pseudo-random cyclic shift, thereby randomizing the inter-cell interference. Each cyclically shifted segment is then processed (e.g., transformed) in a DFT matrix. The cyclically shifted and DFT transformed segments are then IFFT transformed and the block spread sequence of transformed complex valued modulation symbols is transmitted over or within the DFTs-OFDM symbol duration.

Reference Signals (RSs) are also transmitted according to a pattern over the DFTS-OFDM symbol duration. Each RS is IFFT transformed before transmission.

Various embodiments herein include methods of encoding and/or transmitting signaling messages in accordance with the above-described techniques in an LTE-advanced or other wireless communication system. Other embodiments include user equipment or other wireless nodes configured to perform one or more of these methods, including mobile stations configured to encode and/or transmit signaling messages according to these techniques, and wireless base stations (e.g., e-nodebs) configured to receive and/or decode signals transmitted according to these signaling methods. Many of these embodiments may include one or more processing circuits executing stored program instructions for performing the signaling techniques and signaling flows described herein; those skilled in the art will recognize that these processing circuits may comprise one or more microprocessors, microcontrollers, or the like, executing program instructions stored in one or more memory devices.

Of course, those skilled in the art will recognize that the inventive techniques discussed above are not limited to LTE systems or devices having physical configurations equivalent to those proposed above, but will recognize that these techniques may be applied to other telecommunications systems and/or to other devices.

Method steps in the user equipment 10 for transmitting uplink control information to the radio base station 12 over a radio channel in a slot in a subframe according to some general embodiments will now be described with reference to the flowchart depicted in fig. 20. These steps need not be performed in the order recited below, but may be performed in any suitable order. The radio channel is arranged to carry uplink control information and the user equipment 10 and the radio base station 12 are comprised in a radio communications network. The uplink control information is contained in a bit block. In some embodiments, the bit block corresponds to uplink control information and includes jointly coded acknowledgements and negative acknowledgements. The radio channel may be the PUCCH.

Step 201 the user equipment 10 may in some embodiments error correction encode the bit block as indicated by the dashed line. For example, forward error correction processing or the like may be performed on these bit blocks.

Step 202 the user equipment 10 may in some embodiments scramble the bit block before mapping the bit block to the complex valued modulation symbol sequence as indicated by the dashed line. The scrambling procedure is to reduce inter-cell interference and may be cell specific or similar.

Step 203. the user equipment 10 maps the bit block to a complex valued modulation symbol sequence.

And step 204, the user equipment 10 carries out block spreading on the complex value modulation symbol sequence on the DFTS-OFDM symbol by applying the spreading sequence to the complex value modulation symbol sequence, thereby realizing the block spreading sequence of the complex value modulation symbol.

Step 205, the user equipment 10 transforms the block-spread sequence of complex valued modulation symbols according to the DFTS-OFDM symbols by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the block-spread sequence of complex valued modulation symbols. In some embodiments, the matrix includes matrix elements, and the matrix corresponds to a DFT operation along with a cyclic shift operation of a row or column of matrix elements. In some alternative embodiments, the matrix comprising matrix elements corresponds to a discrete fourier transform operation along with a scrambling operation of the matrix elements.

Step 206 the user equipment 10 may in some embodiments further OFDM modulate the block spread sequence of transformed complex valued modulation symbols in DFTS-OFDM symbols as indicated by the dashed lines. For example, the sequence may be transformed in an IFFT process, and a cyclic prefix may be added in a cyclic prefix process.

Step 207. the user equipment 10 transmits the block spread sequence of transformed complex valued modulation symbols to the radio base station 12 over a radio channel. In some embodiments, the transmitting comprises: transmitting a first portion of the sequence of complex valued modulation symbols in a first time slot and a second portion of the sequence of complex valued modulation symbols in a second time slot.

Other variations can be derived depending on whether frequency hopping is applied at the slot boundaries or not.

In some embodiments, a method in a terminal for transmitting uplink control information over a channel in a slot in a subframe to a base station in a wireless communication system is provided. The uplink control information may be included in a codeword. The terminal maps the codewords to modulation symbols. The terminal then block spreads the modulation symbols over the DFTS-OFDM symbols by repeating the modulation symbols for each DFTS-OFDM symbol and applying a block spread sequence of weighting factors to the repeated modulation symbols, thereby achieving a respective weighted copy of the modulation symbols for each DFTS-OFDM symbol, wherein the repeated modulation symbols contain the modulation symbols to which the codeword has been mapped. In some embodiments, the terminal then transforms by precoding or DFTS-OFDM modulating the respective weighted copies of the modulation symbols for each DFTS-OFDM symbol by applying a matrix according to the DFTS-OFDM symbol index and/or slot index to the respective weighted copies of the modulation symbols. The terminal 10 then transmits a respective weighted copy of the transformed modulation symbols to the base station on/within each DFTS-OFDM symbol or each DFTS-OFDM symbol duration. In alternative embodiments, the codeword may be repeated for each DFTS-OFDM symbol and then the repeated codeword containing the already repeated codeword is mapped to a modulation symbol, i.e. in these embodiments the repetition of block spreading and mapping steps are performed in reverse order, and followed by a weighting step.

The channel may be a physical uplink control channel and the codeword may be several bits. The modulation symbols may be QPSK symbols or BPSK symbols. In some embodiments, the block spreading sequence may be an orthogonal sequence. In some embodiments, the step of transforming may comprise cyclically shifting a matrix, which may be a discrete fourier transform matrix.

In order to perform the above method steps for transmitting uplink control information to the radio base station 12 over the radio channel in a slot in a subframe, the user equipment 10 comprises the arrangement depicted in fig. 21. The radio channel may comprise a PUCCH or other uplink control radio channel and is arranged to carry uplink control information. As described above, the bit block may correspond to uplink control information and include jointly coded acknowledgements and negative acknowledgements.

In some embodiments, user equipment 10 may include error correction coding circuitry 211 configured to error correction code the block of bits.

Further, the user equipment may include a scrambling circuit 212 configured to scramble the bit block prior to mapping the bit block to the sequence of complex-valued modulation symbols.

The user equipment 10 comprises a mapping circuit 213 configured to map the block of bits to a sequence of complex valued modulation symbols.

Further, the user equipment 10 includes: a block spreading circuit 214 configured to block spread the sequence of complex valued modulation symbols over the DFTS-OFDM symbol by applying a spreading sequence to the sequence of complex valued modulation symbols, thereby implementing a block spread sequence of complex valued modulation symbols.

The user equipment 10 further comprises: a transform circuit 215 configured to transform the block spread sequence of complex valued modulation symbols by DFTS-OFDM symbols by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the block spread sequence of complex valued modulation symbols. In some embodiments, the matrix may include matrix elements and correspond to a discrete fourier transform operation along with a cyclic shift operation of a row or column of matrix elements. The matrix, which may include matrix elements, may correspond to a discrete fourier transform operation along with a scrambling operation of the matrix elements.

Additionally, the user equipment 10 comprises a transmitter 217 configured to transmit the block spread sequence of transformed complex valued modulation symbols over a radio channel to the radio base station 12. In some embodiments, the transmitter 217 may be configured to transmit a first portion of a sequence of complex valued modulation symbols in a first time slot and a second portion of a sequence of complex valued modulation symbols in a second time slot.

In some embodiments, the user equipment 10 further comprises an OFDM modulator 216 modified or configured to OFDM modulate the block-spread sequence of transformed complex-valued modulation symbols in accordance with DFTS-OFDM symbols. For example, each segment of the block spread sequence of complex valued modulation symbols within the DFTS-OFDM symbol is transformed in transform circuitry 215 by applying the matrix to the segment of the block spread sequence of complex valued modulation symbols, and then OFDM modulated in OFDM modulator 216 and transmitted within the DFTS-OFDM symbol. Transmitter 217 may be included in OFDM modulator 216.

Embodiments herein for transmitting uplink control information over a radio channel to a radio base station 12 may be implemented by one or more processors, such as processing circuitry 218 in a user equipment 10 shown in fig. 21, together with computer program code for performing the functions and/or method steps of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the inventive solution when being loaded into the user equipment 10. One such carrier may be in the form of a CD ROM disc. However, it is feasible for other data carriers, such as a memory stick. Furthermore, the computer program code may be provided as pure program code on a server and downloaded to the user equipment 10.

The user equipment 10 may further comprise a memory 219, the memory 219 being configured for storing data, spreading sequences, matrices and applications for performing the method when running on the user equipment 10 and/or similar devices.

The method steps in the radio base station 12 for receiving uplink control information from the user equipment 10 over the radio channel in a slot in a subframe according to some general embodiments will now be described with reference to the flowchart depicted in fig. 22. These steps need not be performed in the order recited below, but may be performed in any suitable order. The radio channel is arranged to carry uplink control information and the user equipment 10 and the radio base station 12 are comprised in a radio communications network. The uplink control information is contained in a bit block. In some embodiments, the bit block corresponds to uplink control information and includes jointly coded acknowledgements and negative acknowledgements. The radio channel may be the PUCCH.

Step 221. the radio base station 12 receives a complex valued modulation symbol sequence.

Step 222, the radio base station 12 OFDM demodulates the complex-valued modulation symbol sequence.

The radio base station 12 then transforms the OFDM-demodulated complex-valued modulation symbol sequence according to the DFTS-OFDM symbols by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the OFDM-demodulated complex-valued modulation symbol sequence, step 223. In the user equipment 10, this matrix may perform/result in the inverse operation on the matrix G. The inverse operation may comprise an inverse discrete fourier transform operation in some embodiments, and the inverse matrix of matrix G may comprise an inverse discrete fourier transform matrix.

The radio base station 12 also block despreads the complex-valued modulation symbol sequence that has been OFDM-demodulated and transformed with a despreading sequence, such as an orthogonal sequence, step 224.

Step 225 the radio base station 12 maps the despread sequence of complex-valued modulation symbols that have been OFDM-demodulated and transformed to a block of bits representing uplink control information.

Thus, the radio base station 12 can decode the received uplink control information.

The method may be performed by the radio base station 12. Fig. 23 is a block diagram of the radio base station 12 for receiving uplink control information from the user equipment 10 through a radio channel in a slot in a subframe. The radio channel is arranged to carry uplink control information.

The radio base station 12 comprises a receiver 231 configured to receive a sequence of complex-valued modulation symbols and an OFDM demodulation circuit 232 configured to OFDM demodulate the sequence of complex-valued modulation symbols.

Further, the radio base station 12 includes: a transform circuit 233 configured to transform the OFDM-demodulated complex-valued modulation symbol sequence by DFTS-OFDM symbols by applying a matrix according to the DFTS-OFDM symbol index and/or the slot index to the OFDM-demodulated complex-valued modulation symbol sequence. In the user equipment 10, this matrix may perform/result in the inverse operation on the matrix G. The inverse operation may comprise an inverse discrete fourier transform operation in some embodiments, and the inverse matrix of matrix G may comprise an inverse discrete fourier transform matrix.

The radio base station 12 further comprises a block despreading circuit 234 configured to block despread the complex-valued modulation symbol sequence that has been OFDM demodulated and transformed with a despreading sequence.

Further, the radio base station 12 comprises a mapping circuit 235 configured to map a despread sequence of complex-valued modulation symbols that have been OFDM-demodulated and transformed to a block of bits representing uplink control information.

Embodiments herein for receiving uplink control information from a user equipment 10 over a radio channel may be implemented by one or more processors, such as processing circuitry 238 in a radio base station 12 depicted in fig. 23, together with computer program code for performing the functions and/or method steps of embodiments herein. The program code mentioned above may also be provided as a computer program product, for example in the form of a data carrier carrying computer program code for performing the inventive solution when being loaded into the radio base station 12. One such carrier may be in the form of a CD ROM disc. However, it is feasible for other data carriers, such as memory sticks. Furthermore, the computer program code may be provided as pure program code on a server and downloaded to the radio base station 12.

The radio base station 12 may also comprise a memory 239, the memory 239 containing one or more storage units and being configured to store data, spreading sequences, matrices and applications to perform the method when run on the radio base station 12 and/or similar devices.

In the drawings and specification, there have been disclosed exemplary embodiments herein. However, many variations and modifications can be made to these embodiments without substantially departing from the principles of the embodiments. Accordingly, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined by the following claims.

Claims

1. A method in a user equipment (10) for transmitting uplink control information to a radio base station (12) in a time slot in a subframe over a radio channel, the user equipment (10) and radio base station (12) being comprised in a radio communications network, the radio channel being arranged to carry uplink control information, and the uplink control information being comprised in a bit block, the method comprising:

-mapping (203) the block of bits to a sequence of complex valued modulation symbols;

-block spreading (204) the sequence of complex valued modulation symbols over discrete fourier transform spread-orthogonal frequency division multiplexing, DFTS-OFDM, symbols by applying a spreading sequence to the sequence of complex valued modulation symbols to achieve a block spread sequence of complex valued modulation symbols;

-transforming (205) the block-spread sequence of complex-valued modulation symbols by DFTS-OFDM symbols by applying a matrix comprising matrix elements to the block-spread sequence of complex-valued modulation symbols, wherein the matrix elements are cyclically shifted according to DFTS-OFDM symbol indices and/or slot indices; and

-transmitting (207) the block spread sequence of complex valued modulation symbols that has been transformed to the radio base station (12) over the radio channel.

2. The method of claim 1, wherein the matrix corresponds to a discrete fourier transform operation in conjunction with a cyclic shift operation of rows or columns of matrix elements.

3. The method of any of claims 1-2, further comprising:

-error correction coding (201) the block of bits; and

-scrambling (202) the block of bits before mapping the block of bits to the sequence of complex valued modulation symbols.

4. The method of any of claims 1-2, further comprising:

-OFDM modulating (206) said block spread sequence of transformed complex valued modulation symbols by DFTS-OFDM symbols.

5. The method of any of claims 1-2, wherein the transmitting step comprises: transmitting a first portion of the sequence of complex valued modulation symbols in a first time slot and a second portion of the sequence of complex valued modulation symbols in a second time slot.

6. The method of any of claims 1-2, wherein the block of bits corresponds to uplink control information and includes jointly coded acknowledgements and negative acknowledgements.

7. A method in a radio base station (12) for receiving uplink control information from a user equipment (10) in a time slot in a subframe over a radio channel, the radio channel being arranged to carry uplink control information, the uplink control information being comprised in a bit block, and the user equipment (10) and the radio base station (12) being comprised in a radio communications network, the method comprising:

-receiving (221) a sequence of complex-valued modulation symbols;

-orthogonal frequency division multiplexing, OFDM, demodulation (222) of the sequence of complex-valued modulation symbols;

-transforming (223) the complex valued modulation symbol sequence that has been OFDM demodulated by a discrete fourier transform spread DFTS-OFDM symbol by applying a matrix comprising matrix elements to the complex valued modulation symbol sequence that is OFDM demodulated, wherein the matrix elements are cyclically shifted according to a DFTS-OFDM symbol index and/or a slot index;

-block despreading (224) the complex valued modulation symbol sequence that has been OFDM demodulated and transformed with a despreading sequence; and

-mapping (225) the despread sequence of complex-valued modulation symbols that have been OFDM-demodulated and transformed to a block of bits.

8. A user equipment (10) for transmitting uplink control information to a radio base station (12) in a time slot in a subframe over a radio channel, the radio channel being arranged to carry the uplink control information and the uplink control information being contained in a bit block, and the user equipment (10) comprising:

a mapping circuit (213) configured to map the block of bits to a sequence of complex-valued modulation symbols;

a block spreading circuit (214) configured to block spread the sequence of complex valued modulation symbols over a discrete fourier transform spread-orthogonal frequency division multiplexing, DFTS-OFDM, symbol by applying a spreading sequence to the sequence of complex valued modulation symbols to achieve a block spread sequence of complex valued modulation symbols;

a transformation circuit (215) configured to transform the block-spread sequence of complex-valued modulation symbols by DFTS-OFDM symbols by applying a matrix comprising matrix elements to the block-spread sequence of complex-valued modulation symbols, wherein the matrix elements are cyclically shifted according to DFTS-OFDM symbol indices and/or slot indices;

a transmitter (217) configured to transmit the block spread sequence of transformed complex valued modulation symbols to the radio base station (12) over the radio channel.

9. The user equipment (10) according to claim 8, wherein the matrix corresponds to a discrete fourier transform operation together with a cyclic shift operation of rows or columns of matrix elements.

10. The user equipment (10) according to any one of claims 8-9, further comprising:

an error correction encoding circuit (211) configured to perform error correction encoding on the bit block; and

a scrambling circuit (212) configured to scramble the block of bits prior to mapping the block of bits to the sequence of complex valued modulation symbols.

11. The user equipment (10) according to any one of claims 8-9, further comprising:

an OFDM modulator (216) configured to OFDM modulate the block-spread sequence of transformed complex-valued modulation symbols in accordance with DFTS-OFDM symbols.

12. The user equipment (10) according to any of claims 8-9, wherein the transmitter (217) is configured to transmit a first part of the sequence of complex valued modulation symbols in a first time slot and a second part of the sequence of complex valued modulation symbols in a second time slot.

13. The user equipment (10) according to any of claims 8-9, wherein the block of bits corresponds to uplink control information and comprises jointly coded acknowledgements and negative acknowledgements.

14. A radio base station (12) for receiving uplink control information from a user equipment (10) in a time slot in a subframe over a radio channel, the radio channel being arranged to carry the uplink control information, the uplink control information being contained in a bit block, and the radio base station (12) comprising:

a receiver (231) configured to receive a sequence of complex-valued modulation symbols;

an orthogonal frequency division multiplexing, OFDM, demodulation circuit (232) configured to OFDM demodulate the sequence of complex-valued modulation symbols;

a transform circuit (233) configured to transform the OFDM-demodulated complex-valued modulation symbol sequence by discrete fourier transform spread DFTS-OFDM symbols by applying a matrix comprising matrix elements to the OFDM-demodulated complex-valued modulation symbol sequence, wherein the matrix elements are cyclically shifted according to the DFTS-OFDM symbol index and/or the slot index;

a block despreading circuit (234) configured to block despread said complex-valued modulation symbol sequence that has been OFDM demodulated and transformed with a despreading sequence; and

a mapping circuit (235) configured to map a despread sequence of complex-valued modulation symbols that have been OFDM demodulated and transformed to a block of bits.

15. A method in a terminal for transmitting uplink control information over a channel in a slot in a subframe to a base station in a wireless communication system, the uplink control information being contained in a codeword, the method comprising:

-mapping the codeword to modulation symbols;

-block spreading the modulation symbols over DFTS-OFDM symbols by repeating the modulation symbols for each discrete fourier transform spread DFTS-orthogonal frequency division multiplexing, OFDM, symbol and applying a block spreading sequence of weighting factors to the repeated modulation symbols to achieve a respective weighted copy of the modulation symbols for each DFTS-OFDM symbol;

-transforming said respective weighted copy of said modulation symbols for each DFTS-OFDM symbol by applying a matrix comprising matrix elements to said respective weighted copy of said modulation symbols, wherein said matrix elements are cyclically shifted according to a DFTS-OFDM symbol index and/or a slot index; and

-transmitting to the base station on each DFTS-OFDM symbol the respective weighted copy of the modulation symbols that have been transformed.

16. The method of claim 15, wherein the channel is a physical uplink control channel.

17. The method of any of claims 15-16, wherein the codeword is a number of bits.

18. The method according to any of claims 15-16, wherein the modulation symbols are quadrature phase shift keying symbols or binary phase shift keying symbols.

19. The method of any of claims 15-16, wherein the block spreading sequence is an orthogonal sequence.

20. The method of any of claims 15-16, wherein transforming comprises cyclically shifting rows or columns of the matrix, the matrix being a discrete fourier transform matrix.