Abstract: Techniques are provided herein to adaptively and independently disable use of subchannels in transmission sent from a first wireless communication device to a second wireless communication device. The first wireless communication device receives transmission sent to it by the second wireless communication device. The transmissions occupy some or all of a plurality of subchannels within a frequency band that are available for use in the transmission. The transmissions received at the first wireless communication device are evaluated in each subchannel for an over-the-air wireless link between the first wireless communication device and the second wireless communication device. Based on the evaluation, zero or more of the plurality of subchannels are independently disabled in transmissions that are sent by the first wireless communication device to the second wireless communication device.

Abstract: The present invention discloses a base transceiver station (BTS) equipped with a plurality of antennas for improving the robustness of spatial division multiple access via nulling. The BTS comprises of a first matrix module receiving a plurality of signals from one or more customer premises equipments (CPEs) through the plurality of antennas and producing correspondingly a first plurality of covariance matrices representing the plurality of signals, a second matrix module receiving the first plurality of covariance matrices and generating correspondingly a set of derivative spatial signature matrices representing the CPEs respectively, a third matrix module receiving the derivative spatial signature matrices and producing correspondingly a second plurality of covariance matrices representing interferences of the CPEs, and an eigenvector module generating a plurality of beamforming vectors for the CPEs from the plurality of derivative spatial signature matrices and the second plurality of covariance matrices.

Abstract: Techniques are provided to pre-distort a signal that is transmitted by a transmitter of a wireless communication device, e.g., a device configured for wireless radio frequency communication. The transmitter of the device inherently introduces distortion to the baseband signal to be transmitted. In at least one frame of a baseband signal to be transmitted, at least one subcarrier in a preamble of the frame is shifted in frequency such that the at least one subcarrier is offset from a normal subcarrier frequency position. The at least one frame of the baseband signal is supplied to the transmitter that is configured to produce a transmit signal for transmission. The transmit signal at an output of the transmitter is sampled or detected and inter-modulation distortion in the transmit signal is determined at one or more frequencies as a result of shifting of the frequency of the at least one subcarrier in the preamble of the at least one frame.

Abstract: A method is disclosed for optimizing up-link transmit powers of a wireless broadband terminal operating in a predetermined frequency band in a multi-carrier system, the method comprising assigning a transmit signal to one or more sub-carriers of predetermined frequencies, and capping the output powers of the transmit signal to a predetermined level based on the predetermined frequencies, wherein the output power of the transmit signal is lower if frequencies of the transmit signal have less guard band to the edge of the predetermined frequency band.

Abstract: Described herein is a method for obtaining a downlink beamforming weighting vector in a wireless communications system based on channel information about an uplink channel. The method comprises obtaining the channel information about the uplink channel by a means selected from the group comprising of training signals, pilot signals, and data signals, wherein the uplink channel comprises a set of uplink sub-channels, calculating a spatial signature of the uplink channel with the channel information, and computing a downlink beamforming weighting vector of a downlink channel with the spatial signature of the uplink channel, wherein the downlink channel comprises a set of downlink sub-channels that share few or no sub-carriers with the set of uplink sub-channels.

Abstract: In one embodiment, an apparatus includes a receiver configured to receive a transmission from a wireless communication device, the transmission associated with resource units, a detector configured to generate log-likelihood ratio data from the received transmission, and a controller configured to calculate noise and interference for each of the resource units and modify the generated log-likelihood ratio data based on the calculated noise and interference.

Abstract: Techniques are provided herein to enable collaborative spatial multiplexing in a wireless communication system. At M plurality of antennas of a first wireless communication device, N plurality of spatially multiplexed transmissions are received from corresponding ones of N plurality of second wireless communication devices. The first wireless communication device produces M receive signals from the transmissions received at the M plurality of antennas. The first wireless communication device applies beamforming weight vectors to the M receive signals and in so doing produces N signals or signal streams, where N is less than or equal to M. The first wireless communication device then recovers the modulated data for each of the transmissions from the N signals.

Abstract: Techniques are provided to performing beamforming on a wireless communication link that employs multi-carrier code division multiple access (MC-CDMA) signal formatting techniques. At a first wireless communication device, a waveform is received at each of a plurality of antennas, where the waveform comprises a multi-carrier code division multiple access ranging transmission from each of one or more of a plurality of second wireless communication devices such that MC-CDMA ranging transmissions from two or more second wireless communication devices overlap in time and frequency. All codes in a set of possible codes that may be used by the second wireless communication devices are searched to determine whether which codes in the set are present in the one or more MC-CDMA ranging transmissions contained in the received waveform.

Abstract: Techniques are provided herein to segment subcarriers for broadcast transmission to one or more mobile stations. A broadcast message to be transmitted from a first device is generated. The broadcast message comprises a plurality of symbols and each symbol is to be transmitted at a different one of a plurality of frequency subcarriers. The plurality of subcarriers is divided into groups and each group of subcarriers is assigned to a corresponding one of a plurality of antennas of the first device. The groups of subcarriers are transmitted from corresponding ones of the plurality of antennas.

Abstract: A wireless communications system is provided with reduced sideband noise and carrier leakage. In the system, at least one transmitter modulates at least one input signal with a first carrier to generate a modulated output signal, and at least one receiver receives the modulated output signal and demodulates the same with a second carrier to generate at least one demodulated output signal. The first and second carriers are at different frequencies, such that the sideband noise and carrier leakage generated by different sources can be distinguished.

Abstract: An offset direct conversion receiver apparatus and corresponding receiving method are provided. A received wireless signal is directly downconverted and demodulated to a baseband offset frequency that is offset from zero frequency to produce an in-phase (I) baseband offset signal centered at the baseband offset frequency and a quadrature-phase (Q) baseband offset signal centered at the baseband offset frequency. The I baseband offset signal and Q baseband offset signal are bandpass filtered to produce an I bandpass signal and a Q bandpass signal, respectively. The I bandpass signal and the Q bandpass signal are downconverted from the baseband offset frequency to zero frequency to produce an I baseband receive signal and a Q baseband receive signal. A technique and logic are also provided to select the best baseband offset frequency used in an offset direct conversion receiver.

Abstract: A dynamically adaptive channel estimation process is provided for use in a wireless communication device. At a first device, a wireless transmission is received from a second device. The transmission comprises a plurality of successive symbols each of which comprises a plurality of subcarriers. The first device is configured to compute channel characterizing information for a wireless channel between the first device and the second device based on the received values at subcarriers of the successive symbols. The first device is configured to select one of a plurality of channel estimation schemes based on the channel characterizing information, and to compute an estimate of channel information for the wireless channel using the selected one of the plurality of channel estimation schemes.

Abstract: A system and method are provided for detecting locations of a customer premises equipment in a wireless communication system with one or more base transceiver stations and one is efficient. A plurality of antennas in a base transceiver station (BTS) receives signals transmitted from a customer premises equipment (CPE). A timing detection module extracts the timing offset from the receiving signals and a first calculation module calculates the distance between the BTS and the CPE based on the timing offset. A signal detection module detects magnitudes and phases of the receiving signals and a second calculation module determines a dominant beam according to the antenna pattern and calculates the direction of arrival of the dominant beam. A third calculation module calculates the location of the CPE relative to the BTS based on the distance and the direction of arrival.

Abstract: Techniques are provided to determine a more realistic measure of a physical carrier-to-interference plus noise radio (pCINR) associated with a wireless channel between first and second wireless communication devices. Channel conditions are used to derive a channel margin quantity that is in turn used “discount” the pCINR. The discounted pCINR is then used to determine a modulation and encoding scheme that can be used on the wireless channel for communications between the first and second wireless communication devices.

Abstract: The present invention discloses a method for wireless communications network performance in transmitting a message. The method comprises creating a first beamformed virtual antenna for the serving BTS and one or more second beamformed virtual antennas for the one or more target BTSs when one or more predetermined conditions are met, establishing a first beamformed channel by using the first beamformed virtual antenna, establishing one or more second beamformed channels by using the one or more second beamformed virtual antennas, and transmitting a plurality of signals comprising the message via the first and the one or more second beamformed channels.

Abstract: A method is provided for reducing interferences in a wireless communication system. First, in one or more cells, a plurality of frequency-time frames are generated each having at least one predetermined frequency-time open window unused for desired wireless communications. The interference information is derived from the predetermined open windows of the frames. The interference for incoming signals is reduced by calculating beamforming weights using the observed interference information.

Abstract: A method and system are provided for computing beamforming weighting vectors with collaborated uplink sounding in a wireless communications network. The method comprises selecting a designated uplink sounding region and a signal sequence from a set of orthogonal signal sequences; exchanging collaborated uplink sounding information between a base transceiver station (BTS) in a cell and one or more BTSs in its neighboring cells; receiving one or more first sounding signals in the designated uplink sounding region from a first CPE in the cell, which are considered as desired signals; confirming channel-sharing among the first CPE and one or more second CPEs in the neighboring cells; detecting one or more second sounding signals from the one or more second CPEs, which are considered as interference signals; and calculating the beamforming weighting vector using the first one or more sounding signals and the one or more second sounding signals.

Abstract: A method and system are provided to compensate for the nonlinearity of a wireless transmitter. The method includes sending a predetermined input bit stream to the power amplifier, calculating the coefficients of the polynomial representing the response curve of the power amplifier and generating the predistortion coefficients of the polynomial representing the response curve of the predistortor. The method linearizes the response curve of the transmitter chain in a communication device.

Abstract: Techniques are provided for computing beamforming weight vectors useful for multiple-input multiple-output (MIMO) wireless transmission of multiple signals streams from a first device to a second device. The techniques involve computing a plurality of candidate beamforming weight vectors based on the one or more signals received at the plurality of antennas of the first device. A sequence of orthogonal/partially orthogonal beamforming weight vectors are computed from the plurality of candidate beamforming weight vectors. The sequence of orthogonal/partially orthogonal beamforming weight vectors are applied to multiple signal streams for simultaneous transmission to the second device via the plurality of antennas of the first device.

Abstract: Techniques are provided for wireless communication between a first wireless communication device and a second wireless communication device. At a plurality of antennas of the first wireless communication device, one or more signals transmitted by a second wireless communication device in a first frequency band are received. Beamforming weights are computed from information derived from the signals received at the plurality of antennas using one or more of a plurality of methods without feedback information from the second wireless communication device about a wireless link from the first wireless communication device to the second wireless communication device. The beamforming weights are applied to at least one transmit signal to beamform the at least one transmit signal for transmission to the second wireless communication device in a second frequency band.