Abstract: A method for decoding tail-biting convolutional codes is disclosed. In the method, all beginning states of a trellis diagram are initialized. Forward Viterbi metrics are calculated for the trellis diagram. A trace-back process is performed from an ending state of the trellis diagram at a first time instance to a first state where all surviving paths converge at a second time instance. Backward Viterbi metrics are calculated for a predetermined period of time from the first state at the second time instance to a second state at a third time instance. A trace-back process is performed from a designated state, which is equal to the second state, at the first time instance to determine a most likely path for the convolutional codes in the trellis diagram.

Abstract: A method for improving a frequency utilization efficiency for a wireless communication system having a plurality of cells includes the following steps. At least one primary channel is allocated for each cell, the primary channel being different from that of its neighboring cell. One or more secondary channels are allocated for each cell, which have the same frequencies as their corresponding primary channels but differ in configuration, the secondary channels being different in frequency from the primary channel of the same cell. The secondary channel of the cell is activated for carrying communication traffic when the primary channel of the same cell has a capacity of being used exceeding a predetermined threshold value.

Abstract: The present invention discloses a method and system for signal communication in a multi-input multi-output network. The method creates beamformed channels by calculating one or more beamforming weighting vectors corresponding to one or more antennas on the receiving wireless station based on the predetermined receiving signals. The transmitting wireless station transmits one or more beamformed transmission signals to the receiving wireless station using the calculated beamforming weighting vectors for targeting at the antennas thereon, thereby creating two or more detectably uncorrelated transmission signals received at the receiving wireless station.

Abstract: Techniques are provided to facilitate the computation of beamforming weights used by a first communication device when sending a transmission via a plurality of antennas to a second communication device where knowledge of the behavior of the channel between the first communication device and the second communication device is limited to a portion of a wide frequency band. A frequency extrapolation beamforming weight computation process is provided to derive knowledge in other frequency subbands based on information contained in the received transmission from the second communication device.

Abstract: Techniques are provided for selecting one or more downlink beamforming vectors for a wireless channel to create beamformed signals between a first wireless communication device, e.g., a base transceiver station (BTS) and a second wireless communication device, e.g., a mobile station (MS). The method comprises estimating a downlink channel covariance matrix from an uplink covariance matrix of the wireless channel, wherein the uplink covariance matrix is computed based on uplink signals received at the first wireless communication device from the second wireless communication device. A plurality of candidate downlink beamforming weighting vectors are generated from the uplink covariance matrix.

Abstract: Techniques are provided herein for generating multiple radiation patterns. An antenna system comprises an antenna array having one or more antennas for providing a first radiation pattern and a second radiation pattern, a transform matrix for transforming one or more inputs into one or more outputs according to a transform function, wherein the outputs of the transform matrix provide signals to the antennas with predetermined phases and magnitudes for generating the first and second radiation patterns, and a transmitter for providing a first set of signals corresponding to the first radiation pattern and a second set of signals corresponding to the second radiation pattern to inputs of the transform matrix.

Abstract: A method and system are provided for improving the performance of a trellis-based decoder. States with reduced uncertainty (SRUs) are defined for one or more predetermined fields in an encoded message. Metrics are set for the SRUs such that candidate paths through a trellis-based decoding process are eliminated for those states that are not SRUs.

Abstract: A method is provided for selecting multiple customer premises equipments (CPEs) to share a channel in a wireless communications network. The method includes calculating a correlation between spatial signatures of every two CPEs subscribing to a base transceiver station (BTS) of the wireless communications network, wherein two CPEs constitute channel-sharing candidates if their correlation is lower than a predetermined threshold, creating a first set of CPEs of all the member of channel-sharing candidates, counting a number of channel-sharing candidates a CPE relates to for every CPE, selecting a first CPE related to the fewest number of channel-sharing candidates, creating a second set of CPEs by identifying all the CPEs that the first CPE relates to, and selecting a second CPE related to the fewest number of channel-sharing candidates from the second set of CPEs, wherein the first and second CPEs become two selected CPEs to share the channel.

Abstract: Techniques are provided herein to configure first and second wireless communication devices in order to perform bi-directional beamformed multiple-input multiple-output (MIMO) communication. Each device uses received signals from the other device to compute beamforming weight vectors for application to a plurality of signal streams to be simultaneously beamformed transmitted to the other device.

Abstract: Techniques are provided for improving hybrid automatic repeat request retransmissions techniques in a beamformed multiple-input multiple-output wireless communication environment. At a first device comprising a first plurality of antennas, a plurality of beamforming weight vectors are applied to a corresponding plurality of signal streams for simultaneous transmission to a second device having a plurality of antennas. A determination is made whether the plurality of signal streams need to be retransmitted from the first device to the second device. When a retransmission needs to be made, an order in which the plurality of beamforming weight vectors are applied to the plurality of signal streams is switched for a retransmission attempt of the plurality of signal streams from the first device to the second device.

Abstract: Techniques are provided to enable computation of beamforming weights for beamforming MIMO wireless communication between first and second wireless communication devices. At the first device comprising a first plurality of antennas, signals are received that are wirelessly transmitted from a different one of a second plurality of antennas of the second device during a corresponding one of a plurality of time slots. The first device computes beamforming weights from the received signals. When signals are to be transmitted from the first device to the second device, the first device applies the beamforming weights to signals to be transmitted from the first plurality of antennas of the first device to the second plurality of antennas of the second device.

Abstract: A method of signal transmission and reception for a cellular wireless network is provided comprising detecting signal strength of signals transmitted or received between a mobile station and a plurality of base transceiver stations; selecting a plurality of candidate serving base transceiver stations based on the detected signal strength; selecting a first group of serving base transceiver stations from the candidate serving base transceiver stations; and sending signals between the mobile station and the first group of serving base transceiver stations using beam forming technology to reduce interference received by the mobile station.

Abstract: Techniques are provided herein to compute beamforming weight vectors for pre-coding broadcast signals. First, system parameters for a device configured to wirelessly transmit one or more broadcast signals via a plurality of antennas are determined. Based on the system parameters a plurality of beamforming weight vectors are computed. The beamforming weight vectors are computed such that they have omni-directional like characteristics and such that correlation between beamforming weight vectors is relatively low. The plurality of beamforming weight vectors are applied to each of the one or more broadcast signals for transmission by the device to produce beamformed transmit signals for transmission via the plurality of antennas.

Abstract: Techniques are provided to compute the carrier to interference-plus-noise ratio (CINR) in a wireless communication system using log-likelihood ratio (LLR) data generated from a received transmission. The LLR data are collected as they are sent from a detector to a forward error correction (FEC) decoder in a wireless communications device. In one embodiment, decision-aided LLR based CINR is computed using the decoded bits output from the FEC decoder as feedback. In another embodiment, blind LLR based CINR is computed without feedback. The CINR may be used to adjust a modulation and/or coding parameters associated with wireless communication between wireless communication devices.

Abstract: Method and system are provided for improving the performance of a trellis-based decoder. States with reduced uncertainty (SRUs) are defined for one or more predetermined fields in an encoded message. Metrics are set for the SRUs such that candidate paths through a trellis-based decoding process are eliminated for those states that are not SRUs.

Abstract: A closed-loop beamforming weight estimation process in which, at a first device, respective ones of a plurality of beamforming weight vectors are applied to subcarriers associated with a pattern of subcarriers assigned to a corresponding subcarrier stream such that the plurality of subcarriers assigned to a subcarrier stream is weighted by a corresponding one of the plurality of beamforming weight vectors to produce a plurality of beamformed streams transmitted from a plurality of antennas of the first device to a second device. The second device estimates and analyzes the channel information for each of the received beamformed streams to identify at least one of the beamformed streams that is preferred over the others. The second device transmits to the first device a feedback signal that contains information identifying the preferred beamformed stream. The first device computes a plurality of new beamforming weight vectors based on the information identifying the preferred beamformed stream.

Abstract: The present invention discloses a low-complexity estimation method for obtaining a weighting vector for an antenna system with adaptive phased arrays. A first matrix is generated from a plurality of statistically independent symbols of the receiving signals. The plurality of statistically independent symbols is received from two or more antennas over some period of time without a prior knowledge of the properties of the symbols. A second matrix, which is the covariance matrix of the first matrix, is calculated. Subsequently, a column or row is selected from the second matrix to be the weighting vector for two or more antennas in an adaptive phased array antenna system.

Abstract: Techniques are provided to compute beamforming weights at a communication device, e.g., a first communication device, based on transmissions received at a plurality of antennas from another communication device, e.g., a second communication device. A plurality of transmissions are received at the plurality of antennas of the first communication device from the second communication device. A covariance matrix associated with reception of a plurality of transmissions at the plurality of antennas of the first communication device is computed. Corresponding elements (e.g., all the rows or all the columns) of the covariance matrix are combined to produce a weighted channel signature vector. A receive beamforming weight vector is computed from the weighted channel signature vector.

Abstract: A Customer-Premises Equipment (CPE) device includes a power supply for generating a first power at a first voltage level; a rechargeable battery for generating a second power at a second voltage level; and a power amplifier coupled to the power supply and the rechargeable battery for receiving the first power and the second power to output a third power at a third voltage level higher than either the first voltage level or the second voltage level, wherein the third power is utilized to transmit signals from the CPE device to a BTS.

Abstract: Techniques are provided to enable wireless communication between first and second wireless communication devices each having a plurality of antennas, where the second device sends the transmissions via less than all of its plurality of antennas. Each transmission may comprise a plurality of time-frequency instances. At the first communication device, data is derived representing parameters of a communication channel between the plurality of antennas of the first device and all of the plurality of antennas of the second device from the transmissions received at the plurality of antennas of the first device. Beamforming weights for transmitting one or more signal streams via the plurality of antennas of the first device to the plurality of antennas of the second device are computed based on the data representing parameters of the communication channel between the plurality of antennas of the first device and the plurality of antennas of the second device.