Abstract: A wireless communication system, method and apparatus are provided for soft and softer handover of a mobile wireless transmit/receive unit (WTRU) between two or more base stations and/or base station sectors. A network control unit assigns selected base stations to transmit communication data to the WTRU based on the WTRU being disposed in base station or base station sector geographic range of service. A joint detector (JD) receiver is configured to receive and process one or more wireless data signals in each of a series of timeframes where each signal received within a common timeslot has a unique channel encoding of the same communication data. The JD receiver has a plurality of channel estimators that estimate received signals within a common timeslot and a combiner configured to decode and combine the channel estimates to derive a resultant data signal.

Abstract: A method of generating an index value associated with a primary synchronization code within a communication signal includes splitting a sampled communication signal into even and odd samples. The even and odd samples are correlated with a primary synchronization code of the communication signal and complex values of the even and odd samples are generated. Signal strength values for the even and odd samples are approximated and the approximate signal strength values within a frame of the communication signal are accumulated. A highest accumulated signal strength value is assigned as an index value.

Abstract: A method of generating an index value associated with a primary synchronization code within a communication signal includes splitting a sampled communication signal into even and odd samples. The even and odd samples are correlated with a primary synchronization code of the communication signal and complex values of the even and odd samples are generated. Signal strength values for the even and odd samples are approximated and the approximate signal strength values within a frame of the communication signal are accumulated. A highest accumulated signal strength value is assigned as an index value.

Abstract: A method and apparatus is disclosed for reducing multi-user processing at the receiver in wireless communication systems. Detected codes are grouped according to channel impulse response and a parent code is identified for each group of detected codes. A matrix A is constructed and joint detection is performed using the identified parent codes. Data symbols of the detected codes are obtained from the data symbols of the identified parent codes.

Abstract: A method for differential phase evaluation of M-ary communication data is employed in which the data consists of N sequential symbols r1 . . . rN, each having one of M transmitted phases. Selected sequences of N?1 elements that represent possible sequences of phase differentials are evaluated using multiple-symbol differential detection. Using r1 as the reference for each phase differential estimate, sN?1 phase differential sequences are selected in the form (P2i, P3i, . . . , PNi) for i=1 to s for evaluating said symbol set, where s is predetermined and 1<s<M. Each set of s phase differential estimate values are chosen based on being the closest in value to the actual transmitted phase differential value. These s phase differential estimates can be determined mathematically as those which produce the maximum results using conventional differential detection.

Abstract: The present invention is a system and method which controls outer loop transmit power for transmission power of an uplink/downlink communication in a wireless communication system. The system receives a communication from a base station and determines an error rate on the received communication. The system then distinguishes between static and dynamic channels, produces a static adjustment value, and characterizes the dynamic channels to generate a dynamic adjustment value. The target power level is then adjusted by the static and dynamic adjustment values, setting the transmission power level.

Abstract: A method for performing initial cell search in wireless communication system wherein unsuitable cells includes searching stored frequencies exhaustively and initial frequencies non-exhaustively. Initial frequencies may be searched exhaustively in certain circumstances. When performing exhaustive initial cell searches, primary synchronization codes that lead to unsuitable cells are excluded from subsequent initial cell searches performed on the same frequency.

Abstract: Methods for signaling multi-user multiple-input multiple output (MU-MIMO) parameters for Evolved-UTRA (E-UTRA) are disclosed. Example signaling format methods are presented that allow use of distributed virtual resource blocks (DVRB) or support of four wireless transmit/receive units (WTRUs) but maintaining a predetermined signal format size. A signaling format is also presented that signals transmission precoding matrix indexes used by all co-scheduled WTRUs.

Abstract: An automatic gain control (AGC) method according to the present invention applies an initial gain by a digital AGC circuit in a timeslot is determined using a final calculated gain from the same timeslot in the previous frame together with an offset factor. An erase function is activated for a given data sample block when the number of saturated data samples that are detected within the block exceeds a threshold value. The power measurement made by the AGC circuit and used to update the gain is adjusted based on the number of measured data samples that are saturated. These elements provide a gain limiting function and allows limiting of the dynamic range for further signal processing.

Abstract: A method and apparatus for estimating channelization codes in a wireless transmit/receive unit (WTRU) using blind code detection (BCD). A WTRU receives communication bursts and detects a midamble in the received burst. A candidate code list is generated in accordance with the detected midamble. The candidate code list includes channelization codes intended for both the intended WTRU and other WTRUs. Active channelization codes among the codes in the candidate list are identified, and the identified codes are forwarded to a multi-user detector (MUD). The present invention resolves SF ambiguity in the downlink of TSM. Since the orthogonal variable spreading factor code maintains the orthogonality between codes of different SF, SFs of other WTRUs follow the SF of the intended WTRU. Moreover, since the data for other WTRUs is not used in symbol processing after MUD, the performance of MUD for the intended WTRU is preserved with the SF ambiguity of other WTRUs.

Abstract: A method and apparatus for managing power during discontinuous reception (DRX) mode are disclosed. A DRX mode is defined for a wireless transmit/receive unit (WTRU) for reducing power consumption of the WTRU. During the DRX mode, the WTRU enters into a sleep state and periodically wakes up for processing paging blocks for detecting a paging indication for the WTRU and a corresponding paging message. If the WTRU is paged the WTRU terminates the DRX mode. If the WTRU is not paged, the WTRU reenters the sleep state. For power management during the DRX mode, a synchronization update period is defined. The synchronization update period is a period for performing automatic frequency correction and/or frame time correction.

Abstract: A method for determining the validity of a most significant path in a wireless communication system wherein data is transmitted in frame units in a multipath environment begins by accumulating a correlated data sequence N times, each time at a frame offset apart from the previous time. A preliminary noise estimate (PNE) is calculated as an average of the accumulated data values. A preliminary noise threshold (PNT) is calculated according to the equation C1×PNE. A final noise estimate (FNE) is calculated as the average of accumulated data values below the PNT. A final noise threshold (FNT) is calculated according to the equation C2×FNE. The validity of the most significant path is determined if the most significant path value is greater than the FNT.

Abstract: A method and apparatus for deriving a combined transmit power control (TPC) command during handover are disclosed. During handover, a combined TPC command is generated from two or more TPC commands. The combined TPC command is set to ?1 for decrease of the transmit power if a soft symbol of the TPC signal from any cell indicates decrease of the transmit power and the signal-to-interference ratio for the cell is greater than a reliability threshold. Otherwise, the combined TPC command is set to ?1 if the function ? is not greater than the combining threshold, and set to +1 if the function ? is greater than the combining threshold, where the function ? represents a log-likelihood ratio of a probability density function of the combined TPC command.

Abstract: A wireless transmit receive unit (WTRU) provides facilitation of cell search. In one embodiment, received samples are split into a plurality of sample sets for processing. Each of the sets is processed and an accumulated result is divided by an estimated noise value. In another embodiment, a code correlator correlates the received signal with a primary synchronization code and an auxiliary code correlator having a same length as the code correlator correlates the received signal with a code having a low cross correlation with the primary synchronization code. In another embodiment, a division of an accumulated result with a noise estimate is performed using indexes of the most significant bits.

Abstract: A method and apparatus for measuring and reporting a rank and/or a precoding matrix for multiple-input multiple-output (MIMO) communication are disclosed. A metric indicating a channel condition is measured and a rank is selected based on the metric. The metric may be a signal-to-interference and noise ratio (SINR), throughput, a block error rate (BLER), system capacity, a sum rate, or the like. An SINR for each radio block group (RBG) for each rank is calculated. A data rate is calculated for each RBG based on the SINR for each rank. An overall rate for all RBGs is calculated for each rank. At least one rank is selected based on the overall rate. At least one precoding matrix may be selected jointly with or separately from the at least one rank.

Abstract: A method and apparatus are described for avoiding a collision between a scheduling request (SR) and a periodic rank indicator (RI) report or a periodic channel quality indicator (CQI)/precoding matrix indicator (PMI) report.

Abstract: A method and an apparatus are provided for receiving a transport block that is segmented into a plurality of code blocks (CBs), each CB having an attached cyclic redundancy check (CRC), decoding each of the plurality of CBs with attached CRC, determining whether each CRC fails, and in response to a determination that a CRC has failed, transmitting a CB index number of the CB attached to the CRC that has failed. Also provided are a method and an apparatus for a transmitter receiving an index number of a CB for retransmission (CBSIRT) attached with a CRC that has failed, determining the CB that correspond to the CRC that has failed based on the CBSIRT, and retransmitting the failed CB in a subsequent transmission time interval (TTI).

Abstract: A wireless transmit receive unit (WTRU) provides facilitation of cell search. In one embodiment, received samples are split into a plurality of sample sets for processing. Each of the sets is processed and an accumulated result is divided by an estimated noise value. In another embodiment, a code correlator correlates the received signal with a primary synchronization code and an auxiliary code correlator having a same length as the code correlator correlates the received signal with a code having a low cross correlation with the primary synchronization code. In another embodiment, a division of an accumulated result with a noise estimate is performed using indexes of the most significant bits.

Abstract: A method and apparatus is disclosed for reducing multi-user processing at the receiver in wireless communication systems. Detected codes are grouped according to channel impulse response and a parent code is identified for each group of detected codes. A matrix A is constructed and joint detection is performed using the identified parent codes. Data symbols of the detected codes are obtained from the data symbols of the identified parent codes.

Abstract: A wireless transmit/receive unit (WTRU) is configure to receive and sample wireless signals in a shared spectrum where the wireless signal comprise encoded symbols. The WTRU has a channel estimation device configured to process received signal samples to produce an estimate of a channel response of the received signals corresponding to a matrix H. The channel estimation device is preferably configured to process the received signal samples to produce an estimate of noise variance of the received signals. The WTRU preferably has a two stage data estimator that includes a channel equalizer and a despreader. The channel equalizer is configured to process received signal samples using the estimated channel response matrix H and the estimate of noise variance to produce a spread signal estimate of the received signals. The despreader is configured to process the spread signal estimate of the received signals produced by said channel equalizer to recover encoded symbols of the received signals.