Abstract: A method and communication system for selecting a mode for encoding data for transmission in a wireless communication channel between a transmit unit and a receive unit. The data is initially transmitted in an initial mode and the selection of the subsequent mode is based on a selection of first-order and second-order statistical parameters of short-term and long-term quality parameters. Suitable short-term quality parameters include signal-to-interference and noise ratio (SINR), signal-to-noise ratio (SNR), power level and suitable long-term quality parameters include error rates such as bit error rate (BER) and packet error rate (PER). The method of the invention can be employed in Multiple Input Multiple Output (MIMO), Multiple Input Single Output (MISO), Single Input Single Output (SISO) and Single Input Multiple Output (SIMO) communication systems to make subsequent mode selection faster and more efficient.

Abstract: A method for wireless communication combines OFDMA resource allocation and power control policies with cooperative relaying techniques. The techniques are preferably implemented in a dense wireless network of power-limited mobile devices assisted by mobile relay devices having superior power supplies. Preferably, MIMO beamforming techniques are used to further increase energy efficiency and spectral efficiency beyond the increases provided by ODFMA cooperative relaying.

Abstract: The present invention provides methods and apparatus for implementing spatial multiplexing in conjunction with the one or more multiple access protocols during the broadcast of information in a wireless network. A subscriber unit for use in a cellular system is disclosed. The subscriber unit includes: spatially separate receivers, a spatial processor, and a combiner. The spatially separate receivers receive the assigned channel composite signals resulting from the spatially separate transmission of the subscriber downlink datastream(s). The spatial processor is configurable in response to a control signal transmitted by the base station to separate the composite signals into estimated substreams based on information obtained during the transmission of known data patterns from at least one of the base stations. The spatial processor signals the base stations when a change of a spatial transmission configuration is required.

Abstract: The present invention provides methods and apparatus for implementing spatial multiplexing in conjunction with the one or more multiple access protocols during the broadcast of information in a wireless network. A subscriber unit for use in a cellular system is disclosed. The subscriber unit includes a plurality of spatially separate antennas and a transmitter for transmitting a plurality of substreams of a datastream on an assigned channel or slot of a multiple access protocol. The transmitter is arranged to apply each substream to an associated one of the spatially separate antennas.

Abstract: A method and communication system for selecting a mode for encoding data for transmission in a wireless communication channel between a transmit unit and a receive unit. The data is initially transmitted in an initial mode and the selection of the subsequent mode is based on a selection of first-order and second-order statistical parameters of short-term and long-term quality parameters. Suitable short-term quality parameters include signal-to-interference and noise ratio (SINR), signal-to-noise ratio (SNR), power level and suitable long-term quality parameters include error rates such as bit error rate (BER) and packet error rate (PER). The method of the invention can be employed in Multiple Input Multiple Output (MIMO), Multiple Input Single Output (MISO), Single Input Single Output (SISO) and Single Input Multiple Output (SIMO) communication systems to make subsequent mode selection faster and more efficient.

Abstract: A wireless communications adapts its mode of operation between spatial multiplexing and non-spatial multiplexing in response to transmission-specific variables. An embodiment of a wireless communications system for transmitting information between a base transceiver station and a subscriber unit includes mode determination logic. The mode determination logic is in communication with the base transceiver station and the subscriber unit. The mode determination logic determines, in response to a received signal, if a subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing spatial multiplexing or non-spatial multiplexing. In an embodiment, the mode determination logic has an input for receiving a measure of a transmission characteristic related to the received signal.

Abstract: A method, processor and system for linear precoding for a multiple-input communication channel described in terms of an effective mean and an effective correlation is provided. The effective mean and correlation can be the sample mean and correlation of the channel, or they can also include an estimate of the channel and a quality parameter of the estimate. The precode is derived by minimizing a Chernoff bound on the pairwise error probability. It is assumed the channel code is a matrix block code, which includes spatial multiplexing and space-time block codes (STBCs) as special cases. In some cases (e.g., an orthogonal STBC) the codeword separation matrix is a scaled identity matrix. In these cases, the precode that minimizes the Chernoff bound can be determined analytically. It may be necessary to perform a “dynamic water-filling” procedure in order to satisfy constraints on the optimization. In other cases, the codeword separation matrix is not a scaled identity matrix.

Abstract: A wireless communications adapts its mode of operation between spatial multiplexing and non-spatial multiplexing in response to transmission-specific variables. An embodiment of a wireless communications system for transmitting information between a base transceiver station and a subscriber unit includes mode determination logic. The mode determination logic is in communication with the base transceiver station and the subscriber unit. The mode determination logic determines, in response to a received signal, if a subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing spatial multiplexing or non-spatial multiplexing. In an embodiment, the mode determination logic has an input for receiving a measure of a transmission characteristic related to the received signal.

Abstract: The present invention provides methods and apparatus for implementing spatial multiplexing in conjunction with the one or more multiple access protocols during the broadcast of information in a wireless network. A subscriber unit for use in a cellular system is disclosed. The subscriber unit includes a plurality of spatially separate antennas and a transmitter for transmitting a plurality of substreams of a datastream on an assigned channel or slot of a multiple access protocol. The transmitter is arranged to apply each substream to an associated one of the spatially separate antennas.

Abstract: A wireless communications adapts its mode of operation between spatial multiplexing and non-spatial multiplexing in response to transmission-specific variables. An embodiment of a wireless communications system for transmitting information between a base transceiver station and a subscriber unit includes mode determination logic. The mode determination logic is in communication with the base transceiver station and the subscriber unit. The mode determination logic determines, in response to a received signal, if a subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing spatial multiplexing or non-spatial multiplexing. In an embodiment, the mode determination logic has an input for receiving a measure of a transmission characteristic related to the received signal.

Abstract: The invention includes an apparatus and a method for transmitting sub-protocol data units from a plurality of base transceiver stations to a subscriber unit. The method includes estimating time delays required for transferring the sub-protocol data units between a scheduler unit and each of the base transceiver stations. The method further includes the scheduler unit generating a schedule of time slots and frequency blocks in which the sub-protocol data units are to be transmitted from the base transceiver stations to the subscriber unit. The time delays are used to generate the schedule. The time delays can be used to generate a look ahead schedule that compensates for the timing delays of the sub-protocol data units from the scheduler unit to the base transceiver stations. The sub-protocol data units are wirelessly transmitted from the base transceiver stations to the subscriber unit according to the schedule.

Abstract: A method for diversity transmission and reception for channels with intersymbol interference is created. With this method one can transmit from two or more antennas in such a way that a receiver with one or more antennas can benefit from the diversity offered by the difference in channels from the transmit antennas to the receiver antenna(s). The way the transmission and reception is organized makes it relatively simple to in the receiver detect the transmitted symbols despite intersymbol interference in the channel. Due to the increased diversity experienced by the receiver the average power level required at the receiver is reduced which can be used to increase the capacity or coverage of a wireless network and/or reduce the required transmitted power.

Abstract: The present invention provides a diversity transmission system. The diversity transmission system includes a method and system of diversity transmission through a wireless channel formed between multiple transmission antennae of a transceiver and a subscriber unit. The method includes forming a stream of symbols from an incoming data stream. A plurality of the symbols are selected forming a data vector. A maximum delay spread through the wireless channel is determined. The maximum delay spread is generally determined as a multiple of a sample time spacing between elements of the data vector. A plurality of diversity vectors are generated based upon the data vector and the maximum delay spread, each diversity vector includes a plurality of elements. Corresponding elements of the diversity vectors are simultaneously transmitted, each diversity vector transmitted from at least one corresponding antenna of a plurality of spatially separate antennae.

Abstract: Techniques for location-assisted wireless communication use real-time location(s) of wireless transceiver(s) together with stored location-indexed channel information to improve communication over a wireless channel between the transceiver(s). The stored channel information includes channel characteristics (e.g., average power, angle-of-arrival, and time delay of multipath components) that are substantially constant in time but vary gradually as a function of location. Current transceiver location(s) are obtained and used to retrieve stored channel characteristics corresponding to the location(s). The channel information may be used at either or both transceiver(s) to improve reception and/or transmission of signals propagating over the wireless channel. For example, reception may be improved by using path angle information to perform spatially structured reception, or using path delay information to perform temporally structured reception, e.g.

Abstract: A method for diversity transmission and reception for channels with intersymbol interference is created. With this method one can transmit from two or more antennas in such a way that a receiver with one or more antennas can benefit from the diversity offered by the difference in channels from the transmit antennas to the receiver antenna(s). The way the transmission and reception is organized makes it relatively simple to in the receiver detect the transmitted symbols despite intersymbol interference in the channel. Due to the increased diversity experienced by the receiver the average power level required at the receiver is reduced which can be used to increase the capacity or coverage of a wireless network and/or reduce the required transmitted power.

Abstract: The present invention includes a cellular wireless re-use communication system. The communication system includes a base transceiver station cluster. The base transceiver station cluster includes a first plurality of base station transceivers and a plurality of common channel areas. Each common channel area includes a unique set of common assigned channels. Each common channel area further includes at least one subscriber unit. Each subscriber unit within the common channel area receives information signals from a second plurality of base station transceivers through one of the set of common assigned channels that correspond to the common channel area. The common assigned channel includes common transmission characteristics. The common transmission characteristic can include a transmission frequency, a transmission time or a transmission code.

Abstract: The invention includes a MIMO channel emulator that includes a channel emulator matrix. The channel emulator matrix receives N inputs and generating M outputs. The channel emulator matrix includes a plurality of splitters. Each splitter receives at least one of the N inputs, and each splitter generates a plurality of signal paths. The channel emulator matrix further includes at least one phase shifter. Each phase shifter adjustably shifts a phase of at least one signal path. The channel emulator matrix further includes a plurality of combiners. Each combiner receives more than one of the plurality of signal paths. At least one of the combiners receives a phase adjusted signal path, and each combiner generates at least one of the M outputs. The invention can also include a plurality of fading emulators. Each fading emulator receives at least one emulator input. The plurality of emulators generate the N splitter inputs. The fading emulators can include fading delay lines.

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: The present invention includes a wireless communication system. The wireless communication system includes a plurality of transceiver antennae. Each transceiver is spatially separate from at least one other transceiver antenna. Each transceiver antenna includes a transceiver antenna polarization. At least one transceiver antenna has a polarization that is different than at least one other transceiver antenna. Each transceiver antenna transmits a corresponding data stream. The wireless communication system further includes a plurality of receiver antennae. The receiver antennae receive at least one data stream. The transceiver antenna polarization of each transceiver antenna is pre-set to optimize separability of the received data streams. A transmission channel between the transceiver antennae and the receiver antennae can be estimated with a channel matrix. The pre-set transceiver antenna polarization of each transceiver antenna can be determined by minimizing a singular value spread of the channel matrix.

Abstract: The present invention provides a method for controlling a communication parameter in a channel through which data is transmitted between a transmit unit with M transmit antennas and a receive unit with N receive antennas by selecting from among proposed mapping schemes an applied mapping scheme according to which the data is converted into symbols and assigned to transmit signals TSp, p=1 . . . M, which are transmitted from the M transmit antennas. The selection of the mapping scheme is based on a metric; in one embodiment the metric is a minimum Euclidean distance dmin,rx of the symbols when received, in another embodiment the metric is a probability of error P(e) in the symbol when received. The method can be employed in communication systems using multi-antenna transmit and receive units of various types including wireless systems, e.g., cellular communication systems, using multiple access techniques such as TDMA, FDMA, CDMA and OFDMA.