Abstract: The present invention is a method and system for controlling downlink transmission power levels in a spread spectrum time division communication system having frames with time slots for communication, which receives at a user equipment (UE) a downlink communication from a base station and determines an error rate of the received communication. The UE then produces power level adjustments for each of the time slots based in part on the error rate and transmits an uplink communication to the base station which includes the power level. In response to the power level adjustments and (or) other information, transmission power level is set for each time slot in the downlink communication.

Abstract: One out of sixteen preamble signatures is selected. A code is produced based on the selected preamble signature. The produced code is phase rotated to produce a processed preamble signature signal. The processed preamble signature signal is used in processing the CDMA RACH signal and the CDMA RACH signal is used to access a CDMA system.

Abstract: A weighted open loop power control transmitter for controlling transmission power levels using a spread spectrum time division duplex (TDD) technique having frames with timeslots for communication includes a demodulator configured to receive a transmitted signal from the receiver, a channel estimation device, a data estimation device, and a weighted open loop power controller. The weighted open loop power controller includes a power measurement device, a pathloss estimation device configured to receive an interpreted power level from the data estimation device and estimate the pathloss and update a long term average of the pathloss, a quality measurement device, and a transmit power calculation device for determining the transmitter's power level and to control the receiver's amplifier.

Abstract: A plurality of communication bursts are transmitted substantially simultaneously in a time slot of a time division duplex/code division multiple access communication system. The communication system has a maximum number of K midamble shifts. Each burst has an assigned midamble. Each midamble is a shifted version of a basic midamble code having a period of P. A combined signal is received. The combined signal includes a received version of each of the communication burst's midambles. A P by P square circulant matrix is constructed including the K midamble shifts. A channel response is determined for each of the K midamble shifts using a prime factor algorithm (PFA) discrete Fourier transform (DFT) algorithm, the received combined signal and the P by P square circulant matrix. The PFA DFT algorithm has a plurality of stages. Each stage has P inputs.

Abstract: A wireless digital communication system includes a base station in communication with a plurality of user equipment mobile terminals (UEs). The system prioritizes the forwarding of blocks of downlink data to designated ones of the UEs. The system employs adaptive modulation and coding (AM&C) to achieve improved radio resource utilization and provides optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink (DL) channel quality measurements only from those mobile terminals (UEs) with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs.

Abstract: A weighted open loop power control transmitter for controlling transmission power levels using a spread spectrum time division duplex (TDD) technique having frames with timeslots for communication includes a demodulator configured to receive a transmitted signal from the receiver, a channel estimation device, a data estimation device, and a weighted open loop power controller. The weighted open loop power controller includes a power measurement device, a pathloss estimation device configured to receive an interpreted power level from the data estimation device and estimate the pathloss and update a long term average of the pathloss, a quality measurement device, and a transmit power calculation device for determining the transmitter's power level and to control the receiver's amplifier.

Abstract: A wireless digital communication system includes a base station in communication with a plurality of user equipment mobile terminals (UEs). The system prioritizes the forwarding of blocks of downlink data to designated ones of the UEs. The system employs adaptive modulation and coding (AM&C) to achieve improved radio resource utilization and provides optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink (DL) channel quality measurements only from those mobile terminals (UEs) with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs.

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). 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 code division multiple access base station receives K data signals over a shared spectrum. The base station receives and samples a combined signal having the K transmitted data signals. A combined channel response matrix is produced. A block column of a cross correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. A fourier transform of a complex conjugate transpose of the combined channel response matrix multiplied to the combined signal samples is taken. An inverse of a fourier transform of each block entry is multiplied to a result of the fourier transform to produce a fourier transform of the data vector. An inverse fourier transform of the data vector fourier transform is taken to produce data of the K signals.

Abstract: A transmitter site transmits a plurality of different data signals at a chip rate over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A spread data vector is determined using the combined signal samples and the estimated channel response. The data of the different data signals is determined using the spread data vector.

Abstract: One out of sixteen preamble signatures is selected. A code is produced based on the selected preamble signature. The produced code is phase rotated to produce a processed preamble signature signal. The processed preamble signature signal is used in processing the CDMA RACH signal and the CDMA RACH signal is used to access a CDMA system.

Abstract: A multiuser detector method and receiver that detects and decodes synchronous or asynchronous CDMA subchannels having different spreading factors with reduced computational complexity. The multiuser receiver is compatible with ZF-BLE, MMSE, decorrelating detectors and the like using Cholesky decomposition to minimize numeric operations. The receiver and method arranges the columns of system transmission response matrices representing the response characteristics of individual users into a total system transmission response matrix which represents a plurality of matched-filter responses for a given block of received data. The invention when used in conjunction with Cholesky decomposition reduces the number of required mathematic operations prior to parallel matched filtering.

Abstract: A transmitter site transmits a plurality of different data signals at a chip rate over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A spread data vector is determined using the combined signal samples and the estimated channel response. The data of the different data signals is determined using the spread data vector.

Abstract: A method implemented by a user equipment includes selecting a first estimate of a signal-to-noise (SNR) ratio, calculating a first amplitude and first noise variance, calculating a second amplitude and a second noise variance, calculating a second SNR, calculating a resolution value, adjusting the first SNR, and performing estimation iterations until the resolution value is equal to a predetermined value.

Abstract: The present invention is a receiver which includes a blind code detection device for determining the identity of a plurality of channels over which information is to be transmitted when the identity of all channels is not known by the receiver. The blind code detection device generates a candidate channel list filled with the identify of selected channels out of the plurality of channels. A multi-user detection device, responsive to the blind code detection device, processes those channels in the candidate code list.

Abstract: A method of using a mobile unit in a multi-cell communication system to determine whether to commence handover of the mobile unit from a serving base station located in a first cell of the communication system to a target base station located in a second cell of the communication system. The mobile unit determines the serving base station received signal code power (RSCPser), the first cell interference signal code power (ISCPser), the target base station received signal code power (RSCPtar) and the second cell interference signal code power (ISCPtar). If the ratio RSCPser/ISCPser is less than the ratio RSCPtar/ISCPtar, the mobile unit commences handover to the target base station. The multi-cell communication system may be a time division duplex (TDD) system. The mobile unit may send a message to a radio network controller (RNC) in communication with the serving and target base stations to initiate the handover.

Abstract: A method of recovering data for use in a receiver that simultaneously receives a plurality of code division multiple access data signals, each data signal experiencing a similar channel response. A combined signal over the shared spectrum in a time slot is received and sampled. The combined signal comprises the plurality of data signals. The sampled signal is used to estimate the similar channel response, and a channel response matrix is constructed. A channel correlation matrix is constructed based in part on the estimated channel response matrix. A fast Fourier transform (FFT) decomposition of a circulant matrix approximation of the channel correlation matrix, and the sampled data signals, are used to determine a spread data vector. The spread data vector is despread to recover data from the matrix.

Abstract: A time division duplex/code division multiple access user equipment receives a plurality of communication bursts transmitted in a time slot. A midamble code included in a received communication burst is determined. A channelization code of a determined midamble's communication burst is determined. A mapping between channelization codes and midamble codes exists such that each midamble being mapped to at least one channelization code and at least one midamble code being mapped to at least two channelization codes which may be received in communication bursts simultaneously.

Abstract: Data is transferred in a wireless communication system, such as a wireless spread spectrum communication system. A plurality of transmitting antennas are provided. Data is encoded to produce a plurality of data streams for each of the plurality of codes. The plurality of data streams are spread with the plurality of spreading codes, and for each transmitting antenna, one of the spread data streams of each code together is combined to produce a spread data vector. Each transmitting antenna transmits its spread data vector. The transmitted spread data vectors are received by each of a plurality of receiving antennas as a received version, and the data is recovered using the received versions.

Abstract: A wireless digital communication system includes a base station in communication with a plurality of user equipment mobile terminals (UEs). The system prioritizes the forwarding of blocks of downlink data to designated ones of the UEs. The system employs adaptive modulation and coding (AM&C) to achieve improved radio resource utilization and provides optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink (DL) channel quality measurements only from those mobile terminals (UEs) with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs.