Abstract: A method and apparatus for performing uplink transmission in a multiple-input multiple-output (MIMO) single carrier frequency division multiple access (SC-FDMA) system are disclosed. At a wireless transmit/receive unit (WTRU), input data is encoded and parsed into a plurality of data streams. After modulation and Fourier transform, one of transmit beamforming, space time coding (STC) and spatial multiplexing is selectively performed based on channel state information. Symbols are then mapped to subcarriers and transmitted via antennas. The STC may be space frequency block coding (SFBC) or space time block coding (STBC). Per antenna rate control may be performed on each data stream based on the channel state information. At a Node-B, MIMO decoding may be performed based on one of minimum mean square error (MMSE) decoding, MMSE-successive interference cancellation (SIC) decoding and maximum likelihood (ML) decoding. Space time decoding may be performed if STC is performed at the WTRU.

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: The present invention is related to a method and apparatus for automatic frequency correction of a local oscillator. The apparatus receives a carrier signal. The carrier signal includes a code sequence known to the apparatus. The apparatus downconverts the carrier signal to a baseband signal using the local oscillator. The apparatus performs a block correlation of the samples of the baseband signal with the known code sequence to generate a frequency error signal. The frequency error signal is fed back to the local oscillator to correct the frequency error.

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: In a wireless communication system comprising at least one wireless transmit/receive unit (WTRU), a base station, and a radio network controller (RNC), a method for constant envelope orthogonal frequency division multiplexing (CE-OFDM) modulation comprises the WTRU performing an inverse transform on the data. The WTRU next performs constant envelope (CE) modulation on the data and transmits the CE-OFDM data to the base station. The base station receives the data and CE demodulates the data. The base station performs a transform on the demodulated data.

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 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.

Abstract: Data is estimated from a received vector comprising a plurality of communications. A received wireless signal is converted to a baseband signal, which is sampled to produce a received vector. Channel responses are estimated for the received communications. The noise variance is estimated. The noise variance is scaled by a scaling factor. Samples are processed using the estimated channel responses and the scaled noise variance to produce a spread data vector. The spread data vector is despread to recover the data of the received wireless signal.

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: The present invention is for a receiver incorporated into User Equipment (UE) or base stations of a code division multiple access (CDMA) communication system. The UE and base station are in communication with one of the plurality of base stations and receives a communication signal through the receiver. The communication signal is correlated using a delay locked code tracking loop, that estimates and tracks a channel delay. The tracking loop comprises a reference code generator and an interpolator for generating timed signal versions in response to said communication. A timed signal correlator, included in the tracking loop for correlating at least two of the timed signal versions with the code reference signal. The result of the correlation is used for generating an error signal. An automatic power normalization loop (APN), that is responsive to the interpolator, generates a power error signal that normalizes the error signal through a normalization circuit.

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: In a time-division duplex (TDD) system, a reliable initialization scheme that is applicable to an automatic gain controller (AGC) at a base station is implemented in various forms depending on the availability of certain information such as signal-to-interference ratio (SIR), spreading factors and other parameters. A more accurate estimation of the initial control word of a gain-adjustable amplifier for one or more time slots is implemented. The scheme is applicable to AGC initialization for each time slot of the TDD system, but is also applicable to other systems of transmission, without limitation.

Abstract: A code division multiple access communication system transmits a pilot and traffic signal over a shared spectrum. The pilot and traffic signal have an associated code and are received over the shared spectrum. The received signals are sampled and the samples are delayed to produce a window. A weighted value for each despread pilot code window sample is determined using an adaptive algorithm. Each window sample is despread with a traffic code. Each despread traffic code window sample is weighted according to a weight corresponding to its respective pilot code sample.

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: The present invention is for a receiver incorporated into User Equipment (UE) or base stations of a code division multiple access (CDMA) communication system. The UE and base station are in communication with one of the plurality of base stations and receives a communication signal through the receiver. The communication signal is correlated using a delay locked code tracking loop, that estimates and tracks a channel delay. The tracking loop comprises a reference code generator and an interpolator for generating timed signal versions in response to said communication. A timed signal correlator, included in the tracking loop for correlating at least two of the timed signal versions with the code reference signal. The result of the correlation is used for generating an error signal. An automatic power normalization loop (APN), that is responsive to the interpolator, generates a power error signal that normalizes the error signal through a normalization circuit.

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 code division multiple access communication system transmits a pilot and traffic signal over a shared spectrum. The pilot and traffic signal have an associated code and are received over the shared spectrum. The received signals are sampled and the samples are delayed to produce a window. A weighted value for each despread pilot code window sample is determined using an adaptive algorithm. Each window sample is despread with a traffic code. Each despread traffic code window sample is weighted according to a weight corresponding to its respective pilot code sample.

Abstract: A method and system for uplink (UL) synchronization of an uplink transmission from a plurality of wireless transmit/receive units (WTRUs) to a Node-B in a code division multiple access (CDMA) system. A Node-B receives a transmission including a UL synchronization (SYNC_UL) sequence from a WTRU. A sampler samples the transmission at a sampling rate which is higher than a chip rate. The samples are down-sampled and the SYNC_UL sequence is detected at a lower rate. A first significant path location of the detected SYNC_UL sequence is determined, and based on the first significant path location, a final significant path location is determined. The final significant path location is quantized and UpPCHPOS is transmitted to the WTRU to adjust a UL transmission timing.

Abstract: A user equipment (UE) for establishing a communication link comprising a first module for processing a received communication signal and generating an index value associated with a primary synchronization code within said communication signal; a second module for generating a scrambling code group number, a slot offset, and secondary synchronization code based on output provided by the first module; a third module for retrieving a primary scrambling code based on the scrambling code group number and slot offset; and a controller coupled to said first module, second module, and third module for controlling an a search frequency of the UE for establishing a communication link.

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: Data from a plurality of communications is transmitted in a code division multiple access communication system. The transmitted communications are received at a receiver and converted into a baseband signal. The baseband signal is sampled to produce a received vector. An estimating device estimates channel responses as a channel response matrix and estimates a noise variance of the received communications. The noise variance is then scaled using a scaling factor derived from at least one gain factor determined for at least one received communication. The received communications are then equalized using the channel response matrix and the scaled noise variance to produce a spread data vector. The spread data vector is despread in order to detect data transmitted as part of the received communications. In an alternate embodiment, the channel response matrix is scaled instead of the noise variance.