Abstract: A wireless link between a first transmitter and a first receiver in a multiple access communications system is evaluated by receiving, at the first transmitter, information that is intended for a second receiver and that is transmitted in a second transmission mode that is different from the current transmission mode and obtaining an error measure for the information that is received at the first receiver and intended for the second receiver. The obtained error measure is then used to determine if the second transmission mode is an acceptable transmission mode. In an embodiment, if the second transmission mode is determined to be acceptable, then the current transmission mode of the first receiver can be replaced by the second transmission mode. In an embodiment, the current transmission mode is replaced by the second transmission mode only if the second transmission mode is a “higher” transmission mode than the current transmission.

Abstract: The invention includes an apparatus and a method for adjusting a power level of a transmission signal for minimal distortion. The method includes modulating the transmission signal. The modulated transmission signal is processed to reduce a peak to average ratio of the modulated transmission signal based upon modulation parameters of the modulated transmission signal. The power level of the modulated transmission signal is adjusted according to the peak to average ratio of the modulated transmission signal. The transmission signal is amplified and transmitted.

Abstract: The invention includes a full duplex transceiver for transmitting and receiving communication signals. The transceiver includes 1 to N sample and hold circuits. Each sample and hold circuit receives a first signal that includes a far-end signal, and in some cases an echo signal, and in some cases alternatively or additionally cross-talk signals. The transceiver additionally includes a plurality of subtraction circuits. Each subtraction circuit receives an output of at least one of the sample and hold circuits. Each subtraction circuit subtracts at least a fraction of a replica signal from at least a fraction of the output of the at least one of the sample and hold circuits. The subtraction circuits generate an output that represent the far-end signal with substantially reduced echo and/or cross-talk interference, and is available for additional receiver processing.

Abstract: The invention includes an Ethernet transceiver. The Ethernet transceiver includes a plurality of digital signal streams, at least one digital signal stream is coupled to another of the digital signal streams. A transform block transforms a plurality of the digital signal streams from an original domain into a lower complexity processing domain. A processor for joint processes the transformed digital signal streams, each joint processed digital signal stream is influenced by other digital signal streams. An inverse transform block inverse transforms the joint processed signal streams back to the original domain. Another embodiment of the invention includes a method of joint processing a plurality of digital signal streams. A first act of the method includes transforming a plurality of the digital signal streams from an original domain into a lower complexity processing domain.

Abstract: Embodiments of an Ethernet transceiver are disclosed. The Ethernet transceiver includes a plurality of digital signal streams, at least one digital signal stream being coupled to another of the digital signal streams. A domain transformer transforms sub-blocks of each of the plurality of the digital signal streams from an original domain into a lower complexity domain. A processor joint processes the transformed sub-blocks of the digital signal streams, each joint processed digital signal stream sub-block is influenced by other digital signal streams sub-blocks. An inverse transformer inverse transforms the joint processed signal streams sub-blocks back to the original domain.

Abstract: A wireless link between a first transmitter and a first receiver in a multiple access communications system is evaluated by receiving, at the first transmitter, information that is intended for a second receiver and that is transmitted in a second transmission mode that is different from the current transmission mode and obtaining an error measure for the information that is received at the first receiver and intended for the second receiver. The obtained error measure is then used to determine if the second transmission mode is an acceptable transmission mode. In an embodiment, if the second transmission mode is determined to be acceptable, then the current transmission mode of the first receiver can be replaced by the second transmission mode. In an embodiment, the current transmission mode is replaced by the second transmission mode only if the second transmission mode is a “higher” transmission mode than the current transmission.

Abstract: The present invention provides a method and system for receiving a plurality of information signals at a receiver. The information signals each traveling through a corresponding transmission channel. The receiver includes a plurality of receiver channels, wherein each receiver channel receives a corresponding information signal. An amplitude of each received information signal associated with each receiver channel is adjusted so the amplitudes of all the received information signals are as great as possible, while still maintaining a target level of signal error of each of the received information signals. The amplitudes of the received information signals can be additionally adjusted so that the signal errors of each of the received information signals are approximately equal. Each receiver channel can be calibrated by measuring a noise reference and a distortion reference for aiding in the estimation of the received information bit stream.

Abstract: A method and wireless communication system for identifying one or more undesired signals at a multiple input receive unit receiving a desired signal or several desired signals and the undesired signal or signals. A separability condition between the desired signal and undesired signal is provided to enable that the undesired signal can be identified at the multiple input receive unit. The separability condition includes the use of substantially coherent reception at the receive unit and the use of separable training patterns for the desired and undesired signals. Zero tones are included in desired and undesired signals to further enhance signal separability. Signal training at the receive unit is used to derive the corresponding channel matrices for the interferers and mitigate their effects.

Abstract: The present invention provides a method and system for synchronizing a receiver. The method includes receiving a plurality of wireless signals that have traveled through at least one of multiple transmitter antennas and multiple receiver antennas. The receiver is time and frequency synchronized to each of the wireless signals based upon joint statistics of the plurality of wireless signals. The joint statistics can be a function of data patterns, time of arrival estimations, frequency offset estimations, phase offset estimations, timing offset estimations, error correction codes, post processing SNR, pre-processing SNR, PER, BER, correlator outputs, delay spread or doppler spread, of each of the plurality of wireless signals.

Abstract: The invention includes an apparatus and a method for adjusting a power level of a transmission signal for minimal distortion. The method includes modulating the transmission signal. The modulated transmission signal is processed to reduce a peak to average ratio of the modulated transmission signal based upon modulation parameters of the modulated transmission signal. The power level of the modulated transmission signal is adjusted according to the peak to average ratio of the modulated transmission signal. The transmission signal is amplified and transmitted.

Abstract: The present invention provides a method and system for biasing a timing phase estimate of data segments of a received wireless signal. The method includes receiving the wireless signal. A timing phase estimate of the data segments of the wireless signal is pre-set depending upon a phase estimator estimate. The timing phase estimate of the data segments of the wireless signal is further biased as a function of a quality parameter of the wireless signal. The data segments are processed generating a receiving data stream.

Abstract: The present inventions provide methods and systems for reducing the peak to average power ratio of a multi-carrier signal. Reducing the peak to average power ratio of a signal ensures that amplifiers and transmitters are not saturated, causing loss of data. Further, reducing peak to average power ratios reduces the consumption of power during transmission. Peak to average power ratios are reduced by applying a peak reduction signal component to one or more of the plurality of information signals that make up the multi-carrier signal. In one embodiment the peak reduction signal is a basis function of the communication system. The information signal is mapped to duplicate constellation points, which may be easily decoded by a receiver by performing a modulo operation. Negation of the peaks may be performed iteratively to remove any peaks produced during prior peak reduction operations.

Abstract: The present inventions provide methods and systems for reducing the peak to average power ratio of a multi-carrier signal. Reducing the peak to average power ratio of a signal ensures that amplifiers and transmitters are not saturated, causing loss of data. Further, reducing peak to average power ratios reduces the consumption of power during transmission. Peak to average power ratios are reduced by selecting a subset of a plurality of frequencies that make up a multi-carrier symbol. Peak reduction signals, carried at the subset of frequencies, are computed to reduce the PAR of the symbol. In one embodiment, a kernel is generated that has components in the subset of frequencies. The kernel is adjusted to negate one or more peaks in the multi-carrier symbol. The adjustment of the kernel creates a subset of signals of a plurality of signals centered at the plurality of frequencies. Negation of the peaks may be performed iteratively to remove any peaks produced during prior peak reduction operations.

Abstract: A wireless link between a first transmitter and a first receiver in a multiple access communications system is evaluated by receiving, at the first transmitter, information that is intended for a second receiver and that is transmitted in a second transmission mode that is different from the current transmission mode and obtaining an error measure for the information that is received at the first receiver and intended for the second receiver. The obtained error measure is then used to determine if the second transmission mode is an acceptable transmission mode. In an embodiment, if the second transmission mode is determined to be acceptable, then the current transmission mode of the first receiver can be replaced by the second transmission mode. In an embodiment, the current transmission mode is replaced by the second transmission mode only if the second transmission mode is a “higher” transmission mode than the current transmission.

Abstract: The invention includes an apparatus and method for scheduling wireless transmission of data blocks between at least one antenna of a base transceiver station and multiple subscriber units. The scheduling can be based on the quality of a transmission link between the base station antennas and the subscriber units, the amount of data requested by the subscriber units, and/or the type of data requested by the subscriber units. The scheduling generally includes assigning frequency blocks and time slots to each of the subscriber units for receiving or transmitting data blocks. The invention includes a method for transmitting data streams between a base transceiver station and a plurality of subscribers.

Abstract: A method for interference mitigation in a wireless communication system having multiple transmitters and receivers by introducing transmission time delays between the transmission of signals from the individual transmitters to ensure coherent reception of the signals at a specific point in the coverage area, such as at a center of distribution of the receivers. To further aid in interference mitigation the signals are assigned training patterns chosen to be distinguishable by the receiver and to optimize interference mitigation. The training patterns can be selected based on a feedback parameter, e.g., a measure of the quality of interference mitigation obtained from the receiver. The present method can be used in wireless communication systems which re-use frequencies including TDMA, CDMA, FDMA, OFDMA or other multiplex communication systems using a multiple access method or a combination of such methods.

Abstract: A method and apparatus for wireless transmission of a digital bit stream. The present method employs diversity techniques to minimize multipath fading. Digital bits are converted into symbols and the symbols are provided to a number of diversity branches. Each diversity branch has its own antenna. The symbols sent to each diversity branch may be multiplied by a different phase factor or amplitude factor. The phase factors and amplitude factors may be randomly selected. Also, wireless channels can be monitored for channel quality. In this case, the channel quality measurements are used to select the phase factors and the amplitude factors. Also, the symbols can be grouped into frames before transmission. In this case, the frames can be multiplied by matrices comprising phase factors and amplitude factors. Also in this case, the frames can undergo cyclic shifting, which provides an additional measure of diversity.

Abstract: A method for interference mitigation in a wireless communication system having multiple transmitters and receivers by introducing transmission time delays between the transmission of signals from the individual transmitters to ensure coherent reception of the signals at a specific point in the coverage area, such as at a center of distribution of the receivers. To further aid in interference mitigation the signals are assigned training patterns chosen to be distinguishable by the receiver and to optimize interference mitigation. The training patterns can be selected based on a feedback parameter, e.g., a measure of the quality of interference mitigation obtained from the receiver. The present method can be used in wireless communication systems which re-use frequencies including TDMA, CDMA, FDMA, OFDMA or other multiplex communication systems using a multiple access method or a combination of such methods.

Abstract: A method of maximizing a communication parameter, such as data capacity, signal quality or throughput of a channel between a transmit unit with M transmit antennas and a receive unit with N receive antennas and a communication system such as a wireless network (including networks with multiple access techniques such as TDMA, FDMA, CDMA, OFDMA) employing the method. The data is first processed to produce parallel spatial-multiplexed streams SMi, where i=1 . . . k, which are converted or mapped to transmit signals TSp, where p=1 . . . M, assigned for transmission from the M transmit antennas. Corresponding receive signals RSj, where j=1 . . . N, are received by the N receive antennas of the receiver and used to assess a quality parameter, such as a statistical signal parameter including SINR, SNR, power level, level crossing rate, level crossing duration of the signal of a predetermined threshold and reception threshold, or a parameter of the data, such as BER or packet error rate.

Abstract: The present inventions provide methods and systems for reducing the peak to average power ratio of a multi-carrier signal. Reducing the peak to average power ratio of a signal ensures that amplifiers and transmitters are not saturated, causing loss of data. Further, reducing peak to average power ratios reduces the consumption of power during transmission. Peak to average power ratios is reduced by clipping an original signal at transmission. A receiver receives the clipped signal and makes an estimate of the clipped portions of the signal. Using iterative estimations an approximation is made of the clipped portions of the signal. The approximation of the clipped portions of the signal is used to estimate the original signal. The clipped signal reduces the peak to average power ratio of the transmitted signal, and estimation avoids the need for sending side information in order to decode the clipped signal.