Abstract: The apparatus of the present invention comprises a group classification part for classifying the entire channels of the FHSS system into a certain number of groups according to the channel bandwidth unit of an FS interference signal; an FS interference elimination part for eliminating a group in which an FS interference exists from said certain number of groups based on the packet error rate (PER) of said certain number of groups that have been classified; and an FD interference avoidance part for avoiding interference by transmitting a packet only if an interference signal does not exist by estimating the existence of said FD interference signal based on a time sequence with respect to the channel to be used for the next frequency hopping (FH), when transmitting a signal by utilizing FH using channels wherein said FS interference signal does not exist.

Abstract: Systems and methodologies are described that facilitate constructing unitary matrices that may be utilized in linear precoding for multiple-input multiple-output (MIMO) wireless communication systems. Each unitary matrix may be generated by combining (e.g., multiplying) a diagonal matrix with a Discrete Fourier Transform (DFT) matrix. The unitary matrices may be utilized to provide feedback related to a channel and/or control transmission over a channel based upon obtained feedback.

Abstract: A receiver produces optimal weights for cancelling multipath interference. An SINR measurement module generates SINR measurements corresponding to soft symbol estimates produced by a baseband receiver from a received multipath signal. Each soft symbol estimate is replaced with either a hard estimate or a weighted soft estimate based on how each corresponding SINR measurement compares to a predetermined threshold. The received multipath signal and estimated interference signals generated from the hard symbol estimates and/or the weighted soft symbol estimates are combined to produce interference cancelled signals that may be combined via maximum ratio combining to produce an interference-cancelled MRC signal.

Abstract: A method of reporting channel state information (CSI) with reduced feedback overhead in a MIMO-OFDM system is provided. A receiver first estimates CSI of a multiple-input multiple-output (MIMO) channel based on a sounding signal transmitted from a transmitter. The CSI comprises L channel response matrices, and each matrix corresponds to an OFDM tone in the MIMO channel. Each channel response matrix is then decomposed into a first CSI component and a second CSI component. The receiver selects a first subset of the first CSI component based on a first tone group size and a second subset of the second CSI component based on a second tone group size. Finally, the receiver transmits the selected subsets of the first and the second CSI components to the transmitter. The reduced feedback does not have significant loss in the information content of CSI because of the coherent bandwidth in typical OFDM systems.

Abstract: In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. After each stage of interference cancellation, interference characteristics change. An adaptive strategy is used in which after each stage of interference cancellation, impairment covariance is parametrically updated and combining weights of the receiver are adapted to reflect the updated impairment covariance.

Abstract: Techniques are provided to allow for implicit determination of the full spatial signature of a wireless channel between first and second wireless devices for multiple-input multiple-output (MIMO) wireless communication between the first and second wireless devices. The first wireless device receives uplink signals at a plurality of antennas of the first wireless device that are transmitted via a plurality of antennas of a second wireless device. Values at a plurality of subcarriers of the received signals across the plurality of antennas of the first wireless device are derived. Using a sliding window for groups of adjacent subcarriers, downlink beamforming weights are computed for each group of subcarriers using channel information of one or more proximate groups of subcarriers. The downlink beamforming weights for the respective groups of subcarriers are applied to a number of spatial streams in a downlink transmission to be transmitted to the second wireless device.

Abstract: Techniques are described herein that receive communications transmitted according to different operation modes at a multi-mode, programmable receiver system. The multi-mode, programmable receiver system may receive communication signals from transmit antennas in “cells” (e.g., base station transceivers and/or the like) according to one or more operation modes, using receive antennas. The received signals may be converted and processed by various modules of the multi-mode, programmable receiver system to produce an output signal. The multi-mode, programmable receiver system includes modules that are programmable to be selectively enabled or disabled according to an operation mode in accordance with which the multi-mode, programmable receiver system operates.

Abstract: All data symbols used in data transmission of a modulated signal are precoded by switching between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol along the frequency axis and the time axis all differ. A modulated signal with such data symbols arranged therein is transmitted.

Abstract: To realize quick adaptation to a communication link between a transmitter and a receiver by using two different frequency carriers. A receiver detects a preamble from a transmission bit string. When determining that a total sum of the number of modified bits exceeds a certain threshold in a range of a payload following the preamble (when detecting that a reception state of a communication link has been degraded), the receiver issues, to a transmitter, a request for changing a transmission parameter (four parameters may be used for enhancement/lowering) for the transmission bit string by using a communication link, which is a relatively-low-frequency carrier. On the other hand, the transmitter receives the request for change, and executes the request for changing the transmission parameter for the transmission bit string while maintaining transmission of a payload in the transmission bit string.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for antenna switching diversity comprising: identifying the start of an OFDM symbol period; switching from an original antenna to an alternative antenna; calculating a signal quality metric associated with the original antenna and the alternative antenna; and selecting either the original antenna or the alternative antenna for demodulation of a current OFDM symbol based on the calculated signal quality metric. In one aspect, the antenna switching diversity is based on either symbol rate switching or block rate switching, and a selection of one or the other is made.

Abstract: A radio access network (RAN) may receive signals with a plurality of antennas. Each antenna may receive a respective incoming signal. Based on the received signals, the RAN may determine an interference factor that relates to interference across the various respective incoming signals received by each antenna. The RAN may also use various criteria and formulas to calculate the interference factor. Once the RAN determines the interference factor, the RAN may determine to operate the receiver in one of two modes. The RAN may operate either in a Maximal Ratio Combining mode or in an Interference Rejection Combining mode. The RAN may periodically re-determine the interference factor and responsively re-determine the operation mode.

Abstract: Transmitter apparatus to broadcast coded orthogonal frequency-division multiplexed (COFDM) radio-frequency carriers conveying digital television (DTV) signals encoded using Bose-Chaudhuri-Hocquenghem (BCH) coding concatenated with subsequent low-density parity-check coding (LPDC) transmits the same coded DTV signals twice some time apart. The coded DTV signals are mapped to quadrature amplitude modulation (QAM) of the COFDM carriers. Preferably, the circular Fourier transforms of COFDM symbols in the earlier transmissions are rotated one half revolution respective to the circular Fourier transforms of corresponding COFDM symbols in the later transmissions. Receiver apparatus combines the earlier and later transmissions of twice-transmitted COFDM signals as part of iterative procedures for de-mapping QAM and decoding the concatenated BCH-LDPC coding of the DTV signals.

Abstract: A receiving apparatus includes: a transmission path characteristics estimating section obtaining pre-interpolation transmission path characteristic data as estimate values for transmission path characteristics as characteristics of a transmission path of an OFDM signal for transmission symbols of pilot signals by using the pilot signals contained in the OFDM signal, and filtering the pre-interpolation transmission path characteristic data by using an interpolation filter, thereby obtaining transmission path characteristic data as estimate values for transmission path characteristics for transmission symbols of the OFDM signal; a distortion correcting section performing distortion correction for the OFDM signal by using the transmission path characteristic data; and a filter controlling section controlling a pass band of the interpolation filter.

Abstract: A mobile device comprises multiple receive antennas to receive spatially independent multipath signals from multiple transmit antennas located on a single base station. The mobile device concurrently generates a RAKE-based equivalent single path signal (RAKE ESPS) and an equalizer-based equivalent single path signal (equalizer ESPS) for the multipath signals received via each receive antenna. The generated RAKE ESPS or the generated equalizer ESPS is selected for channel decoding. Reference signal components are extracted from the multipath signals received to determine noise components, which is used to determine signal quality information of the generated RAKE ESPS and the generated equalizer ESPS. A final ESPS is selected from the generated RAKE ESPS and the generated equalizer ESPS based on the corresponding determined signal quality information. The selected final ESPS is diversity processed by combining signal components over the transmit/receive antennas.

Abstract: A method for improving multiple-input multiple-output MIMO downlink transmissions includes obtaining a channel state information CSI report including preferred matrix index PMI for precoding, channel quality index CQI and rank index RI at a base station from user terminals through a channel feedback; applying selectively a signal-to-interference-plus-noise-ratio SINR offset to a SINR of said CSI report; applying selectively a rate matching responsive to SINR offset or the CSI report; and controlling or adjusting the SINR offset.

Abstract: Provided is a sequential transmission multi-beamforming apparatus and method with a low complexity based on a Hadamard matrix. A simple codebook may be generated based on the Hadamard matrix and thus, a number of weighted-vectors is reduced and a complexity of hardware is decreased. A diversity gain may be maximized based on a spatial diversity processing apparatus and a beamforming weighted vector may be systematically generated.

Abstract: A method includes receiving at a receiver a signal including reference symbols that is sent over a communication channel from a transmitter to the receiver. A response of the communication channel is estimated by applying one or more weighting values to the reference symbols. A noise correction factor is computed based on the weighting values. An estimate of a noise level in the received signal is computed based on the estimated response of the communication channel and the noise correction factor. The received signal is decoded based on the estimate of the noise level.

Abstract: A method and apparatus are provided for feedback for closed-loop transmitting with multiple transmit antenna elements and multiple receive antenna elements. A base station includes a codebook containing sets of weightings for the multiple transmit antenna elements, with each set of weightings identified by an index and the codebook known to the base station and a served mobile station (MS). The base station pre-codes pilot signals using a precoding matrix, preferably a unitary matrix, to produce pre-coded pilot signals, which precoding matrix may or may not be known to the MS and which precoding matrix may or may not be included in the codebook. The base station then transmits the pre-coded pilot signals to the MS via the multiple transmit antenna elements and, in response, receives an index to a set of weightings in the codebook for use in a subsequent transmission of a data stream.

Abstract: A process and receiver for canceling interference generated by a set interference base stations in a synchronized OFDM communication system and receiver in a User Equipment comprising a set of Nrx antennas. The process and receiver that cancels interference generated by a set of base stations performs OFDM demodulation on a receiver signal for each antenna of a user equipment (UE). The process and receiver also monitors each UE antenna for pilot signals generated by nearby base stations. Then the process or receiver extracts the pilot signals and establishes a list of existing base station antennas. The channel power of any interfering antennas is measured and then the Nrx-N most powerful antenna is selected. The process or receiver then performs a joint detection of the N useful Data Symbols (UDS), together with the (Nrx-N) Interfering Data Symbols (IDS) that are demodulated by demodulation blocks.

Abstract: A multi-antenna codebook selection modulation method for solving weak scattering is provided by the present invention. The method obtains higher diversity gain from a combination of multi-antenna codebook pre-coding and a rotation modulation solution by designing a new codebook selection rule. The present invention employs a design solution of designing a higher-order modulation diversity and space interleaver to obtain the higher diversity gain. In addition, the number of transmission antennas and the number of rotation modulation dimension can be set arbitrarily. However, the present invention takes the number Nt of transmission antennas to be equal to the number D of rotation modulation dimension in order to obtain higher diversity gain. In this way, the method evenly disperses signals of each dimension after D-dimensional rotation to each antenna through space interleaving technique, so that the signals of each dimension suffer different fading, thus enabling space diversity gain.

Abstract: The invention describes a method for predicting the performance of the MLD receiver in MIMO channels. The method is based on the iterative principle where the performance of the MLD decoder is derived from that of an iterative receiver architecture with similar performance. The described Iterative MIMO Effective SNR (IMES) technique maps the performance of each MIMO channel realization into a set of effective SNR values for the different streams. This set of effective SNR values can then be used to provide link adaptation feedback to the transmitter so that the most suitable transmission format can be selected according to the characteristics of the propagation channel. Alternatively, this information can be used to adapt the receiver processing to the channel conditions, thereby making it possible, for example, to reduce the receiver power consumption in good signal conditions.

Abstract: The method is based on a signal interval (DB) which comprises a first part (ET) (which is modulated using a first modulation method (GFSK)) of the signal interval and a second part (which is modulated using a second modulation method (DMPSK)) of the signal interval. The channel parameters (c(i)) relating to the second part (which is modulated using the second modulation method) of the signal interval are determined using a received data signal (a(i); p(i)) from the first part (ET) of the signal interval (DB).

Abstract: Techniques to calibrate downlink and uplink channels to account for differences in the frequency responses of transmit and receive chains are described. In one embodiment, pilots are transmitted on downlink and uplink channels and used to derive estimates of the downlink and uplink channel responses, respectively. Sets of correction factors are then determined based on estimates of downlink and uplink channel responses. A calibrated downlink channel is formed using a first set of correction factors for the downlink channel, and a calibrated uplink channel is formed using a second set of correction factors for the uplink channel. The first and second sets of correction factors may be determined using a matrix-ratio computation or a minimum mean square error computation. The calibration may be performed in real-time based on over-the-air transmission. Other aspects, embodiments, and features are also claimed and described.

Abstract: Provided are a device and method for estimating carrier frequency offset of OFDM signals transmitted and received through a plurality of polarized antennas that may accurately estimate carrier frequency offset used for carrier frequency synchronization acquisition when there is interference between polarized waves.

Abstract: A system including a diversity module and an antenna selection module. The diversity module is configured to measure (i) a first signal-to-noise ratio and a first error rate associated with a first antenna, and (ii) a second signal-to-noise ratio and a second error rate associated with a second antenna. The antenna selection module is configured to select the first antenna or the second antenna by comparing (i) the first signal-to-noise ratio to the second signal-to-noise ratio, and (ii) the first error rate to the second error rate.

Abstract: A method of detecting a desired signal within a composite signal provides for suppression of interfering signal(s). The method, implemented in a wireless communication apparatus, for example, includes receiving the composite signal and obtaining sample values therefrom. At least some of the sample values include desired and interfering signal components. The method further includes generating an interfering signal channel estimate by: forming sample pairs for some or all of the sample values; identifying sample pairs of interest as those sample pairs in which the interfering signal component is the same; and calculating the interfering signal channel estimate as an average value determined from one or more of the sample pairs of interest. The method further includes detecting desired signal symbols from the composite signal in a joint detection process that functionally depends on the interfering signal channel estimate.

Abstract: A base station is provided. The base station includes a transmit path circuitry configured to transmit downlink control information in a downlink control information (DCI) format to a subscriber station, and a receive path circuitry configured to receive multiple-input multiple-output (MIMO) feedback from the subscriber station in response to the downlink control information. The MIMO feedback from the subscriber station is determined by two or more codepoints in the DCI format. One of the two or more codepoints indicates a rank-limited single user multiple-input multiple-output (SU-MIMO) feedback corresponding to a rank up to a maximum rank.

Abstract: A multiple-input multiple-output (MIMO) system for demapping uses a single stream system of iterative passes in a preferred order using the latest soft-information for better interference cancellation and the minimum mean square error (MMSE) criterion.

Abstract: In a MIMO system using a cross-polarized antenna structure, even if no ideal XPD can be obtained, the interference between different polarized waves can be reduced to allow an effective precoding to be executed. When a MIMO communication is performed between a transmitter (250) and a receiver (260) each using a cross-polarized antenna structure, a channel estimating and precoding selection section (214) of the receiver (260) performs a channel estimation of MIMO channels from the transmitter to the receiver, decides a precoding matrix (P) of a projection matrix for mutually orthogonalizing or substantially orthogonalizing the channel response matrixes for respective different polarized waves, and feeds the determined precoding matrix (P) back to the transmitter (250).

Abstract: A receive signal processor jointly detects a signal-of-interest with one or more other signals. The signal-to-interference-plus-noise ratio for the signal-of-interest is determined by computing per-subcarrier signal-to-interference-plus-noise ratios for a plurality of subcarriers carrying the signal-of-interest, computing per-subcarrier capacities for the subcarriers based on the per subcarrier signal to interference ratios, and computing a total signal-to-interference-plus-noise ratio for the subcarriers based on the per-subcarrier capacities of the subcarriers.

Abstract: Provided is a decoding apparatus capable of reducing the error rate of the decoding results and also the circuit scale. A computing unit computes a plurality of distances only for a number of code word candidates of code words from demodulated data, the number being smaller than a number of values the code words can express, the code words having a possibility of being transmitted. A decoding unit decodes the code words from the plurality of computed distances. This invention is applicable to a decoding apparatus for Long Term Evolution (LTE).

Abstract: Methods and systems for mitigating interference or estimating a covariance matrix in a communication system are disclosed. In some embodiments, a method of demodulating a received signal in a communication system includes receiving a first plurality of waveforms, estimating a covariance matrix based on the first plurality of waveforms, determining a spatial filter based on the estimated covariance matrix, receiving a second plurality of waveforms, generating at least one filtered waveform by applying the spatial filter to the second plurality of waveforms, and demodulating the at least one filtered waveform.

Abstract: In the communications system of the present invention, a communications terminal determines a precoding matrix index in a pilot signal received through a specific downlink channel, examines channel quality information of the downlink channel according to the determined precoding matrix index, and transmits feedback information to a serving base station, which determines a priority factor by using the examined channel quality information, and compares the priority factor with other priority factors. The comparison is used such that a base station having a high priority suggests the use of the precoding matrix to the neighboring base station.

Abstract: Techniques for transmitting data from multiple transmit antennas using space orthogonal resource transmit diversity (SORTD) are described. For the SORTD scheme, a different orthogonal resource may be assigned to each transmit antenna. Data may be sent from the multiple transmit antennas using multiple orthogonal resources. In one design, a UE may process at least one information bit (e.g., with joint or independent coding) to obtain first and second sets of at least one modulation symbol. The UE may process the first set of modulation symbol(s) for transmission from the first transmit antenna using a first orthogonal resource. The UE may process the second set of modulation symbol(s) for transmission from the second transmit antenna using a second orthogonal resource. Each orthogonal resource may include a different reference signal sequence or a different set of reference signal sequence and orthogonal sequence.

Abstract: A roulette table, including an electronic system having at least one electronic circuit, a number of M antennas, a Code Division Multiple Access (CDMA) transmitter for sending a number of M orthogonal code sequences via the antennas, and a contactless communication interface for receiving the position from an electronic memory of the electronic circuit, in which the antennas are arranged below stake fields of the roulette table, and having chips, in which each chip is equipped with an electronic circuit.

Abstract: A method and system for wireless communication in a wireless station including a transceiver with multiple antennas, is provided. In one implementation, the wireless station performs multiple modulation communication by multiplexing different signal carrier modulation formats by antenna cross polarization multiplexing, including mapping the modulation formats to multiple antenna cross polarization branches. Communication power is allocated for each polarization branch by selectively distributing power to each of the polarized antennas based on at least one of: application data rate requirements, communication link quality indication (LQI) and delay spread of cross polarized channels. Data is transmitted utilizing the modulation formats simultaneously at the same frequency over multiple cross polarized antennas.

Abstract: A method and apparatus for transmitting a downlink signal in a multiple input multiple output (MIMO) wireless communication system is disclosed. A method for receiving a downlink signal from a base station to a user equipment in a multiple input multiple output (MIMO) system, which supports dual layer transmission based on first and second antenna ports, comprises receiving downlink control information (DCI) through a downlink control channel; and receiving downlink data through a downlink data channel, the downlink data including one or more of a first transport block and a second transport block, wherein the downlink control information includes a new data indicator (NDI) for each of the first and second transport blocks, and if the first transport block is disabled and the second transport block is enabled, the new data indicator for the first transport block indicates an antenna port through which the second transport block is received.

Abstract: An estimate of a multiple input, multiple output (MIMO) channel is computed, and an equalizer to be applied to signals received via the MIMO channel is computed. The equalizer is initialized based on the estimate of the MIMO channel. The equalizer is applied to a received signal, and the received signal is demodulated to generate a demodulated signal. The demodulated signal is decoded according to an error correction code to generate decoded data, and the decoded data is re-encoded according to the error correction code to generate re-encoded data. The re-encoded data is re-modulated to generate a re-modulated signal. The received signal is compared to the re-modulated signal, and the equalizer is updated based on the comparison. After updating the equalizer, the equalizer is applied to the received signal.

Abstract: A transmitter includes multiple transmit antennas, a conversion unit configured to generate multiple signal sequences corresponding to a predefined frequency bandwidth from one or more transmission streams associated with any of the transmit antennas, a precoding unit configured to weight the signal sequences with a precoding matrix selected from a codebook including multiple predefined precoding matrices, and a transmitting unit configured to convert an output signal from the precoding unit into a number of signals corresponding to the number of transmit antennas and transmit the converted signals from the transmit antennas. The precoding unit applies distinct precoding matrices to different signal sequences, and an association between the distinct precoding matrices and the different signal sequences is determined through open-loop control being independent of a feedback from a receiver.

Abstract: A wireless communication system is disclosed. The system performs data transmission from a first terminal including N antennas to a second terminal including M antennas using spatially multiplexed streams (N and M are integers larger than or equal to 2).

Abstract: In addition, to pilot tones which may be existent within an orthogonal frequency division multiplexing (OFDM) signal, one or more data tones within that same signal may be employed to assist with channel estimation (alternatively, detection). Once a data tone qualifies as a pseudo-pilot tone, it may be used with the pilot tones for channel estimation. A qualifier considers slicer error associated with hard decisions for a data tone to determine if it is a candidate for assistance within channel estimation. A frame within an OFDM signal may, in one situation, include no pilot tones at all, and a previously calculated channel estimate may be used to process that frame. In addition, fewer pilot tones than needed to perform accurate channel estimation (based on the channel delay spread) may be employed by using one or more pseudo-pilot tones (e.g., qualified data tones).

Abstract: A method of uplink transmission from a mobile device having multiple antennas to a base station having multiple antennas includes transmitting in an open-loop single-user MIMO mode when the mobile device is at high speed, transmitting in a closed-loop single-user MIMO mode when the mobile device is at low speed, and, upon request, transmitting in a multi-user collaborative MIMO mode. The method also includes controlling uplink transmissions in a selected one of the open-loop single-user MIMO, the closed-loop single-user MIMO and the multi-user collaborative MIMO modes. Uplink transmissions from the mobile device may be transmitted using multiple antennas of the mobile device. Upon request, the mobile device may switch to transmitting in multi-user collaborative MIMO mode with a subset of the multiple antennas.

Abstract: Provided is a spectrum sensor for cognitive wireless communication whereby it is possible to improve communication efficiency. In a cognitive wireless communication system, a spectrum sensor senses spectra in multiple frequency bands. A spectrum sensor is configured to be able to operate in one operation mode selected from among a spectrum sensing mode for sensing spectra, and a communication mode for communicating with a wireless communication device. Further, the spectrum sensor is provided with a controller for controlling the operation mode. The controller switches between the above-mentioned operation modes during the symbol period of an ultra-wideband physical layer (UWB PHY).

Abstract: Provided is a method of generating an adaptive codebook and a multiple input multiple output (MIMO) communication system using the adaptive codebook. A transmitter and a receiver may generate, from a base codebook based on a matrix associated with statistics of a channel matrix, the adaptive codebook maintaining a unitary characteristic. The transmitter may perform scheduling, transmit filter design, and precoding using adaptive codebook based feedback information.

Abstract: A noise thresholder of a baseband modem integrated circuit (BMIC) compares measured noise variances on corresponding receiver paths to a pre-established threshold minimum value. The noise thresholder assigns as a noise variance value for a corresponding receiver path either (a) a measured noise variance value for each receiver path having a measured noise variance that is larger than the pre-established threshold minimum, and (b) the pre-established threshold minimum value for each receiver path having a measured noise variance that is less than or equal to the pre-established threshold minimum value. A noise balancer performs noise balancing to provide a same signal to noise ratio (SNR) across all receiver paths, based on the assigned noise variances provided at the noise thresholder. A detection engine utilizes a lowest assigned noise variance value and outputs yielded by the noise balancer to simplify equalization computations while providing a high performance symbol detection capability.

Abstract: The current application is directed to maintaining the correct number of symbols in a protocol frame in a digital communications receiver, to prevent catastrophic failure due to dynamic multipath or cycle slips. Timing recovery and framing are coherent, facilitated by placing channel estimation directly into a larger timing recovery loop.

Abstract: An apparatus for calculating receive parameters for an MIMO system including a plurality of individual transmission sections, a transmission section having a transmit circuit adjustable by a transmit parameter, and a plurality of individual users, a user having a receive circuit being adjustable by a receive parameter, includes a calculator for calculating a receive parameter for a first selected data stream for a first user of the plurality of users using a channel information for a transmission channel between the user and a first individual transmit section, to which the user is associated, and for calculating a receive parameter for a second selected data stream for a second user of the plurality of users associated with a second different individual transmission section using channel information between the first user and the second transmission section the second user is associated with, or using the calculated receive parameter for the first user.

Abstract: A wireless communication terminal includes an antenna selecting unit that selects, for each packet, an antenna for use in receiving signals from among a plurality of a plurality of antennas; a packet-destination judging unit that judges whether a packet obtained by demodulating a signal received by the receiving antenna selected by the antenna selecting unit is destined for the wireless communication terminal; and a stand-by-antenna determining unit that determines a stand-by antenna for use in receiving a packet to be received next based on a result of selection made by the antenna selecting unit and a result of judgment made by the packet-destination judging unit.

Abstract: Soft decision sections provisionally decide each modulated signal separated using an inverse matrix calculation of a channel fluctuation matrix at separation section. Signal point reduction sections reduce candidate signal points of a multiplexed modulated signal using the provisional decision results. Soft decision sections make a correct decision using the reduced candidate signal points and obtain received data of each modulated signal. This allows received data RA, RB with a good error rate characteristic to be obtained with a relatively small number of calculations without reducing data transmission efficiency.

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.