Abstract: A method and system for beamforming in a multiple user multiple input multiple output (MIMO) communication system using a codebook may include a processor in a node B that enables generation of an interference cancellation matrix (WR). The interference cancellation matrix, also referred to as a matched filter, may enable a composite signal (Y) to be represented as a plurality of subsidiary signals (yi), each of which is transmitted by the node B for reception at a corresponding ith UE station. Each of the subsidiary signals yi may be generated based on a corresponding one of a plurality of data stream signals (xi). The processor may enable generation of a precoding matrix (WT) based on the interference cancellation matrix. A transmitter within the node B may enable generation of a plurality of signals based on the precoding matrix. The signals may be transmitted via a wireless communication medium.

Abstract: In transmit pre-coding, a bandwidth and a feedback period to one or more CQI reporting units and a bandwidth and a feedback period to one or more PMI reporting units are assigned, respectively. Sub-divisions in time and/or frequency corresponding to the assigned bandwidths and the assigned feedback periods are dynamically adjusted based at least on uplink channel state information corresponding to the bandwidth and the feedback period assigned to the CQI reporting units, and the bandwidth and the feedback period assigned to the PMI reporting units. One or more feedback messages are generated based at least on the channel state information over the adjusted sub-divisions in time and/or frequency corresponding to the CQI reporting units and to the PMI reporting units, respectively. The bandwidth and/or the feedback period may be assigned based on the channel state information or as a function of a feedback rate.

Abstract: A method and system for beamforming in a multiple user multiple input multiple output (MIMO) communication system using a codebook may include a processor in a node B that enables generation of an interference cancellation matrix (WR). The interference cancellation matrix, also referred to as a matched filter, may enable a composite signal (Y) to be represented as a plurality of subsidiary signals (yi), each of which is transmitted by the node B for reception at a corresponding ith UE station. Each of the subsidiary signals yi may be generated based on a corresponding one of a plurality of data stream signals (xi). The processor may enable generation of a precoding matrix (WT) based on the interference cancellation matrix. A transmitter within the node B may enable generation of a plurality of signals based on the preceding matrix. The signals may be transmitted via a wireless communication medium.

Abstract: Aspects of a method and system for adaptive allocation of feedback resources for CQI and transmit pre-coding may include assigning a bandwidth and a feedback period to one or more CQI reporting units and a bandwidth and a feedback period to one or more PMI reporting units. One or more feedback messages may be generated based at least on channel state information associated with the bandwidth and the feedback period assigned to the one or more CQI reporting units and with the bandwidth and the feedback period assigned to the one or more PMI reporting units. The bandwidth and the feedback period of the CQI reporting units and/or the PMI reporting units may be adjusted dynamically and/or adaptively. Based on the channel state information or as a function of a feedback rate, the bandwidth and/or the feedback period may be assigned.

Abstract: A method and system for communicating feedback information in a multiple user multiple input multiple output (MU-MIMO) communication system are presented. In one aspect of the method and system, a beamformer station may communicate a feedback information request to a plurality of beamformee stations. The feedback information request may request feedback data for a plurality of RF channel bands. The RF channel bands may form a multichannel. The beamformer may subsequently transmit a plurality of signals utilizing the RF channel bands within the multichannel. Each of the beamformees may receive the plurality of subsequently transmitted signals. A beamformee may generate the requested feedback data for each RF channel band within the multichannel. The beamformee may generate a beamforming report, which comprises the feedback data, which is generated across the plurality of RF channel bands in the multichannel. The beamformee may transmit the beamforming report to the beamformer.

Abstract: Aspects of a method and system for reconfigurable SFBC/STBC in a diversity transmission system are presented. Exemplary aspects of the system may include one or more circuits that enable generation of a plurality of codeword sequences based on a data sequence. In a diversity transmission system, the plurality of codeword sequences may be concurrently transmitted via at least a portion of a plurality of transmitting antennas. The concurrently transmitted codeword sequences may enable a diversity receiver to generate the data sequence. In a single input single output transmission system, one or more circuits may enable transmission of one of the plurality of codeword sequences via one of the plurality of transmitting antennas. The transmitted codeword sequence may enable a receiver to generate the data sequence.

Abstract: Aspects of a method and system for predicting CQI values for ML detection in a 2×2 MIMO system are presented. In one aspect of the system, a CQI value for a MIMO communication system may be computed based on a computed channel realization by reverse mapping the computed channel realization to a corresponding CQI value. Based on the computed CQI value, a coding rate may be selected. The coding rate may be selected from a lookup table, wherein the computed CQI value is utilized as an index to the lookup table. The reverse mapping may utilize a function, which is computed using radial basis function networks. In another aspect of the system, a joint mutual information value may be computed for the MIMO communication system. The joint mutual information value may be computed based on a Shannon mutual information value and a matched filter mutual information value.

Abstract: Aspects of a method and system for predicting CQI values for ML detection in a K×K MIMO system are presented. In one aspect of the system, a CQI value for a K×K MIMO communication system may be computed by decomposing the K×K MIMO system into a series of 2×2 MIMO systems. For each 2×2 MIMO system a CQI value may be computed by reverse mapping a PER computed for the 2×2 MIMO system and an SNR value for a SISO communication system. By summing CQI values among the series of 2×2 MIMO systems a CQI value for the K×K MIMO system may be computed. Based on the computed CQI value for the K×K MIMO system, a coding rate may be selected. The selected coding rate may be selected to maximize a computed information throughput rate at a MIMO receiver that utilizes ML detection.

Abstract: Aspects of a system for subspace beamforming for near capacity MIMO performance may include a MIMO transmitter that computes one or more rotation angle values (?f) based on a channel estimate matrix (H). In instances when each rotation angle is computed based on a Euclidean distance criterion, each value ?f may also be computed based on a computed Euclidean distance. Alternatively, in instances when each rotation angle is computed based on a bit error rate (BER) criterion, each value ?f may also be computed based on a signal noise power level (N0). A plurality of spatial stream signals (xi) may be generated utilizing one or more constellation types. The constellation map for each constellation type may be rotated based on a corresponding value ?f. A plurality of transmit chain signals (txi) may be generated based on the signals xi and transmitted via a communication medium characterized by matrix H.

Abstract: Aspects of a method and system for approximate maximum likelihood (ML) detection in a multiple input multiple output (MIMO) receiver may comprise computing soft decision values for bits that may be decoded from a received signal vector by utilizing approximate ML detection. The soft decision values may be computed for at least a portion bits carried within a received signal vector by decomposing a candidate constellation vector into segments, with each dimension representing a spatial stream signal. After decomposition, soft decision values for at least a portion of the bits may be computed by selecting values in a search dimension and computing values in a plurality of slice dimensions. Values within the search dimension may be determined by selecting constellation points within a constellation map for the search dimension. Values within each slice dimension may be computed for each selected constellation point.

Abstract: A method and system for beamforming in a multiple user multiple input multiple output (MIMO) communication system using a codebook may include a processor in a node B that enables generation of an interference cancellation matrix (WR). The interference cancellation matrix, also referred to as a matched filter, may enable a composite signal (Y) to be represented as a plurality of subsidiary signals (yi), each of which is transmitted by the node B for reception at a corresponding ith UE station. Each of the subsidiary signals yi may be generated based on a corresponding one of a plurality of data stream signals (xi). The processor may enable generation of a precoding matrix (WT) based on the interference cancellation matrix. A transmitter within the node B may enable generation of a plurality of signals based on the preceding matrix. The signals may be transmitted via a wireless communication medium.

Abstract: Aspects of a method and system for SFBC and/or STBC using interference cancellation are presented. Aspects of an exemplary system may enable rate 5 4 coding in diversity communication systems that utilize SFBC and/or STBC. A transmitting station may utilize SFBC or STBC to generate and/or concurrently transmit a plurality of signals symbols, which are encoded to enable rate 5 4 transmission. A receiving station may decode rate 5 4 encoded signals utilizing various methods to achieve interference cancellation. The interference cancellation may cancel at least a portion of intersymbol interference, which may occur among symbols in the received rate 5 4 encoded signals. Various methods may be utilized to compute estimated values for at least a portion of the symbols. These methods may include the class of linear estimation methods, such as minimum mean squared error (MMSE) estimation.

Abstract: Aspects of a system for STBC/SFBC in a communication system using angle feedback may include a receiver, which enables reception of signals via a plurality of receiving antennas. The receiver may enable computation of a rotation factor value based on the received signals and utilization of the computed rotation factor value to receive subsequent signals via the plurality of receiving antennas. The received signals may comprise preamble data. The receiver may enable computation of channel estimate values based on the received preamble data. A rotation angle value may be computed based on the computed channel estimate values. The rotation factor value may be computed based on the computed rotation angle value. The receiver may enable transmission of feedback information comprising the computed rotation factor and/or the computed rotation angle.

Abstract: Aspects of a method and system for CQI/PMI feedback for precoded MIMO systems utilizing differential codebooks may include generating one or more feedback messages for one or more Channel Quality Indicator (CQI) reporting units based on at least channel state information associated with the one or more CQI reporting units. One or more differential feedback messages may be generated for one or more Pre-coding Matrix Index (PMI) reporting units based on at least channel state information associated with the one or more PMI reporting units, wherein the one or more PMI reporting units span a useable bandwidth. A bandwidth and a feedback period may be assigned to each of the one or more CQI reporting units and the one or more PMI reporting units to define the one or more CQI reporting units and the one or more PMI reporting units.

Abstract: Aspects of a method and system for reconfigurable SFBC/STBC in a diversity transmission system are presented. Exemplary aspects of the system may include one or more circuits that enable generation of a plurality of codeword sequences based on a data sequence. In a diversity transmission system, the plurality of codeword sequences may be concurrently transmitted via at least a portion of a plurality of transmitting antennas. The concurrently transmitted codeword sequences may enable a diversity receiver to generate the data sequence. In a single input single output transmission system, one or more circuits may enable transmission of one of the plurality of codeword sequences via one of the plurality of transmitting antennas. The transmitted codeword sequence may enable a receiver to generate the data sequence.

Abstract: Aspects of a method and system for adaptive allocation of feedback resources for CQI and transmit pre-coding may include assigning a bandwidth and a feedback period to one or more CQI reporting units and a bandwidth and a feedback period to one or more PMI reporting units. One or more feedback messages may be generated based at least on channel state information associated with the bandwidth and the feedback period assigned to the one or more CQI reporting units and with the bandwidth and the feedback period assigned to the one or more PMI reporting units. The bandwidth and the feedback period of the CQI reporting units and/or the PMI reporting units may be adjusted dynamically and/or adaptively. Based on the channel state information or as a function of a feedback rate, the bandwidth and/or the feedback period may be assigned.

Abstract: Aspects of a method and system for reordered QRV-LST (layered space time) detection for efficient processing for multiple input multiple output (MIMO) communication systems are presented. The method may include receiving an ordered plurality of signals wherein each of the ordered plurality of received signals comprises information contained in an ordered plurality of spatial streams. Each spatial stream may comprise one or more frequency carriers, or tones. Information, or data, contained in a corresponding one of the ordered plurality of spatial streams may be detected. The order in which the information is detected may be determined for each individual frequency carrier.

Abstract: A spatial diversity receiver and method for determining a multichannel combined symbol timing marker that identifies an energy concentration for a combination of channel delay spreads in order to reduce the complexity of equalization. The receiver includes two or more receiver chains having spatially diverse antennas; a multichannel combined timer; and a multichannel combined equalizer for receiving wireless signals through two or more signal channels. The multichannel combined timer combines energies corresponding to the channel impulse response coefficients for all the channels for determining a series of multichannel combined metrics having associated index cursors, and then determines the multichannel combined symbol timing marker from the index cursor for the largest of the metrics. The symbol timing marker synchronizes the received symbols issued to the equalizer jointly to the energy concentration for the delay spreads combined for all the channels.

Abstract: A decision feedback equalizer receiver that assigns a number F of feedforward filter taps and optimizes digital receiver performance in multipath channel environments, where F is an integer less than a memory length of a radio channel. The feedforward filter taps are assigned to delay times corresponding to an optimum burst timing parameter delay time, d(0), and to F-1 time delays based on "tap SNR indices." For an Uncorrelated Inter-Symbol-Interference (UISI) case, the F-1 time delays are the first F-1 rank ordered time delays are selected as the feedforward tap delay times. For a general case, a combination of the UISI case and an analytical two cluster case is obtained by selecting the first F-2 rank ordered time delays and a 2D time delay, where D is the delay time corresponding to the largest estimated tap SNR index.

Abstract: A transmission system for backhauling CDMA signals from remote antennas to the centralized base station of a wireless communication system includes a laser transmitter and an optical receiver coupled to an optical fiber. Wireless signals are backhauled to the central base station without degrading signal quality, and with minimal signal processing performed at the remote antenna site. The RF drive current driving the laser transmitter is kept above a predetermined level to prevent noise caused by optical feedback into the laser transmitter caused by Rayleigh backscatter in the optical fiber. A method of testing the optical link is presented which avoids the expense of using a real CDMA system to test each link. The testing method enables the dynamic range of inexpensive, unisolated, uncooled lasers in the optical link to be increased so the optical link can cost-effectively backhaul the CDMA signals.