Abstract: A method of and system for determining cross-polarization isolation is described. In one embodiment, a modulated signal is obtained from a communication link. The modulated signal includes a modulated co-polarized signal component and a modulated cross-polarized signal component. Cross-polarization isolation is determined using the modulated co-polarized signal component and the modulated cross-polarized signal component. The determined cross-polarization isolation can be used to adjust an antenna.

Abstract: A method and apparatus for communicating wirelessly comprising creating a plurality of sub-carrier signals by quadrature amplitude modulating data onto a plurality of sub-carrier frequencies spaced apart by a sub-carrier frequency spacing interval, frequency shifting the sub-carrier signals by one half of the sub-carrier frequency spacing interval, and modulating the sub-carrier signals onto a radio frequency carrier wave for wireless transmission.

Abstract: The computation of code-specific channel matrices for an Assisted Maximum Likelihood Detection (AMLD) receiver comprises separately computing high rate matrices that change each symbol period, and a low rate matrix that is substantially constant over a plurality of symbol periods. The high and low rate matrices are combined to generate a code-specific channel matrix for each receiver stage. The high rate matrices include scrambling and spreading code information, and the low rate matrices include information on the net channel response and combining weights. The low rate matrices are efficiently computed by a linear convolution in the frequency domain of the net channel response and combining weights (with zero padding to avoid circular convolution), then transforming the convolution to the time domain and extracting matrix elements. Where the combining weights are constant across stages, a common code-specific channel matrix may be computed and used in multiple AMLD receiver stages.

Abstract: A receiver for discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM) based systems, including a prefilter for received signal codeword(s); and a log-likelihood ratio LLR module responsive to the prefilter; wherein the prefilter includes a pairing and whitening module that based on channel estimates and data rate enables the LLR module to perform either a Serial-In-Serial-Out (SISO) based log likelihood ratio processing of an output from the paring and whitening module or a two-symbol max-log soft output demodulator (MLSD) based log likelihood ratio processing of an output from the pairing and whitening module.

Abstract: A Software Defined Radio (SDR) subsystem capable of supporting a multiple communication standards and platforms for modulation, demodulation and trans-modulation of an input signal is provided. The SDR subsystem includes a Signal Conditioning Cluster (SCC) unit that includes a signal conditioning CPU adapted for sample based signal processing, a Signal Processing Cluster (SPC) unit that includes a signal processing CPU adapted for block based signal processing, and a Channel Codec Cluster (CCC) unit that performs a channel encoding or a channel decoding operation.

Abstract: A set of one or more receiver parameters is adjusted. It is determined whether to adjust the set of receiver parameters. In the event it is determined to adjust the set of receiver parameters, a new set of values is generated for the set of receiver parameters using a cost function (where the cost function does not assume a noise signal in a receive signal to have a particular statistical distribution) and the set of receiver parameters is changed to have the new set of values.

Abstract: A receiver receives an inter-symbol correlated (ISC) signal with information symbols and a corresponding parity symbol. Values of information symbols are estimated utilizing parity samples that are generated from the parity symbols. One or more maximum likelihood (ML) decoding metrics are generated for the information symbols. One or more estimations are generated for the information symbols based on the one or more ML decoding metrics. A parity metric is generated for each of the one or more generated estimations of the information symbols. The parity metric is generated by summing a plurality of values of one of the generated estimations to generate a sum, and wrapping the sum to obtain a parity check value that is within the boundaries of a symbol constellation utilized in generating the information symbols.

Abstract: According to one embodiment, a method of transmitting a broadcast signal includes: encoding physical layer pipe (PLP) data for delivering a service; mapping the encoded PLP data to symbols; building a signal frame based on the mapped symbols; modulating the signal frame according to an orthogonal frequency division multiplexing (OFDM) scheme; inserting a pilot symbol into a beginning part of the modulated signal frame; and transmitting the broadcast signal including the signal frame and the inserted pilot symbol. The pilot symbol comprises an effective portion, a cyclic prefix obtained by frequency-shifting a first portion of the effective portion, and a cyclic suffix obtained by frequency-shifting a second portion of the effective portion.

Abstract: A communication apparatus for executing half-duplex data communication conforming to V.

Abstract: An apparatus including an adder, a delay line, and a first detector. The adder may be configured to generate an input signal in response to a received signal and a feedback signal. The feedback signal may include a contribution from each of a plurality of delayed versions of the input signal. The contribution from each of the plurality of delayed versions of the input signal may be determined by a respective weight value. The delay line may be configured to generate the plurality of delayed versions of the input signal. The first detector may be configured to recover a data sample from the input signal in response to a clock signal.

Abstract: A likelihood value calculation device includes: likelihood value calculation unit 201 that takes as input an equalization signal of a modulated signal, and that, in accordance with a first control signal, calculates from the equalization signal a provisional likelihood value for which the bit value of each signal point is “0” for each bit position; arithmetic inversion unit 202 that, in accordance with a second control signal, supplies for each bit position the provisional likelihood value without alteration or subjects the provisional likelihood value to arithmetic inversion and supplies the likelihood value following inversion; and operation control unit 200 that holds, for each combination of a radio mode and a modulation mode, a control pattern used to control the likelihood value calculation unit 201 and arithmetic inversion unit 202 and that generates the first and second control signals in accordance with the control pattern designated from among these control patterns.

Abstract: This disclosure relates a method and apparatus for generating pre-coding matrix codebook. The method for generating pre-coding matrix codebook, comprising: acquiring a universal set of pre-coding matrixes in a first format; acquiring a universal set of pre-coding matrixes in a second format; selecting a first predetermined number of pre-coding matrixes in the first format from the universal set of pre-coding matrixes in the first format; and selecting a second predetermined number of pre-coding matrixes in the second format from the universal set of pre-coding matrixes in the second format, according to the selected first predetermined number of pre-coding matrixes in the first format.

Abstract: A method and an apparatus for obtaining a precoding matrix indicator is disclosed, which relates to the field of communication technologies. The method includes: obtaining a first rotation matrix according to first channel information; obtaining a first differential matrix according to the first rotation matrix and a currently-obtained instantaneous beam forming matrix/precoding matrix; and quantizing, according to a first differential codebook, a pre-acquired first rank indicator, and preset quantization criteria, the first differential matrix to obtain a differential precoding matrix indicator. The apparatus includes: a first rotation matrix obtaining module, a first differential matrix obtaining module, and a differential precoding matrix indicator obtaining module. The differential PMI is obtained according to the channel information, and the differential PMI is used for feedback.

Abstract: To feedback MIMO channel conditions, a codeword from a codebook is selected. To reduce signalling, the codewords are organized into codeword subsets. The receiver signals an index of a codeword into a current codeword subset previously made known to the transmitter. The current codeword subset is adaptively selected based on a threshold criterion. For example, if the best codeword from the current codeword subset is not sufficiently similar to the best codeword in the full codebook, a switch in the codeword subset is made.

Abstract: Disclosed are a method and apparatus of adaptive transmission signal detection based on a signal-to-noise ratio and a Chi-squared distribution for decoding a reception signal in the form of multi-streams into a transmission signal, the method comprising: receiving a reception signal vector; estimating a channel matrix of a channel that the reception signal vector experienced; performing QR decomposition based on the estimated channel matrix; calculating dimensions of divisional spaces adaptively on the basis of a signal-to-noise ratio (SNR) or a signal-to-interference noise ratio (SINR); detecting a maximum likelihood point having a maximum likelihood value among lattice points within each divisional space obtained on the basis of results from performing the QR decomposition and calculating dimension of the divisional spaces; and recovering a transmission signal vector based on the detected maximum likelihood points.

Abstract: In accordance with a method for diversity combining in an orthogonal frequency division multiple access (OFDMA) system, repetition diversity equalization and combining may be performed with respect to received OFDMA signals. In addition, receiver antenna diversity equalization and combining may be performed with respect to the received OFDMA signals. The repetition diversity equalization and combining and the receiver antenna diversity equalization and combining may be performed in accordance with a maximum ratio combining (MRC) scheme.

Abstract: A closed-loop multi-antenna system and method thereof are provided. A transmitter includes a feedback information processor and a first transmit unit. A receiver includes a channel estimator, a feedback information generator and a second transmit unit. The feedback information processor receives feedback information from the receiver, calculates each of a sum rate in a multi-user mode and a sum rate in a single-user mode using the feedback information, and selects one of the single-user mode and the multi-user mode as a transmission mode depending on a comparison result between the sum rate in the multi-user mode and the sum rate in the single-user mode. The channel estimator acquires channel quality information (CQI) for each data stream transmitted individually via each antenna group. The feedback information generator determines the CQI associated information from the CQI acquired individually for each antenna group corresponding to the transmission mode.

Abstract: A full-rate distributed space-time (ST) code design is provided for amplify-and-forward cooperative wireless channels. A signal space diversity technique is employed at the source node and a unique signature vector at each relay node. The distributed space-time (ST) codes can achieve full cooperative diversity and full rate. The achievable diversity gain is M+1, where M is the number of relay nodes. Optimal power allocation can be used to maximize the coding gain under a total power constraint.

Abstract: In a symbol mapping method, transmission data is encoded to generate information bits and redundancy bits. An average LLR value of bits on which the information bits are mapped is different from an average LLR value of bits on which the redundancy bits are mapped.

Abstract: A plurality of wireless channels link a transmitter and a receiver, each channel corresponding to a different transmit-receive antenna pair. Channel state information is estimated for the plurality of wireless channels by grouping the plurality of channels into one or more groups, each group including the channels associated with two or more collocated transmit and/or receive antennas. A set of delay tap values is iteratively estimated in the time domain for each group of channels so that the channels included in the same group are associated with the same delay tap values. A frequency domain channel response of each of the channels included in the same group of channels is estimated based on the set of delay tap values estimated for the group.

Abstract: The invention relates to a EHF wireless communication receiver comprising a phased array radio arranged for receiving a beam of signals in a predetermined frequency band. The phased array radio comprises a plurality of antenna paths, each arranged for handling one of the incoming signals and forming a differential I/Q output signal, each antenna path comprises a downconversion part and a phase shifting part for applying a controllable phase shift; a signal combination circuitry is connected to the antenna paths and is arranged for combining the differential I/Q output signals; and a control circuitry is connected to the phase shifting parts of the antenna paths and is arranged for controlling the controllable phase shift. In each antenna path, the phase shifting part is a baseband part downstream from the downconversion part and the phase shifting part comprises a set of variable gain amplifiers arranged for applying controllable gains to the respective downconverted incoming signals in the I/Q branches.

Abstract: A method and apparatus for generating soft-decision output values for a set of transmitted spatial streams in a multiple-input multiple-output (MIMO) communication system are described. The apparatus includes a processor and memory with executable instructions. A plurality of constellation points for respective transmitted spatial streams are looped over to estimate values for other transmitted streams based at least in part on Reduced List Detection (RLD). The plurality of constellation points is a subset of all possible constellation points determined around a spatial stream where more constellation points are assigned to spatial streams with a weaker signal strength than for spatial streams with a stronger signal strength. A set of distance metrics as values of the plurality of constellation points for the respective transmitted spatial streams are determined. Soft-decision outputs for the respective transmitted streams based at least in part on the set of distance metrics are generated.

Abstract: In accordance with a method for identifying a preamble sequence and for estimating an integer carrier frequency offset, a signal that comprises a preamble sequence from a set of possible preamble sequences is received. A reduced set of integer carrier frequency offset (CFO) candidates may be determined. Cross-correlation operations may be performed with respect to the received signal and multiple candidate transmitted signals. Each candidate transmitted signal may include one of the set of possible preamble sequences. In addition, each candidate transmitted signal may correspond to one of the reduced set of integer CFO candidates. Multiple correlation values may be determined as a result of the cross-correlation operations. The correlation values may be used to identify the preamble sequence and to estimate the integer CFO.

Abstract: Disclosed is a BSLM method of generating U independent alternative symbol sequences by changing a phase of symbol sequences by phase sequences and transmitting the alternative symbol sequences with a PAPR to lower the PARR of a transmission signal of a transmitter in an OFDM system. The transmitter uses m-sequences as the phase sequence and a receiver uses an ML decoder to distinguish the phase sequence. The BSLM method includes rotating phases in blocks according to the m-sequences used in the respective symbol sequences, selecting a signal sequence with a minimum PAPR among U alternative signal sequences generated by the m-sequences in the transmitter, and partitioning U alternative symbol sequences into U/2 blocks in the transmitter. Block partitioning and predetermined phase rotation are used to embed side information in an alternative signal sequence, and the BSLM scheme may be extended to a BPTS.

Abstract: This disclosure relates a method and apparatus for generating pre-coding matrix codebook. The method for generating pre-coding matrix codebook, comprising: acquiring a universal set of pre-coding matrixes in a first format; acquiring a universal set of pre-coding matrixes in a second format; selecting a first predetermined number of pre-coding matrixes in the first format from the universal set of pre-coding matrixes in the first format; and selecting a second predetermined number of pre-coding matrixes in the second format from the universal set of pre-coding matrixes in the second format, according to the selected first predetermined number of pre-coding matrixes in the first format.

Abstract: Disclosed herein is a reception apparatus, including: a reception section adapted to receive an OFDM (Orthogonal Frequency Division Multiplexing) signal obtained by modulating a first frame configured so as to include packets of a common packet sequence configured from a packet common to a plurality of streams and a second frame configured so as to include packets of a data packet sequence configured from packets individually unique to the plural streams; an acquisition section adapted to acquire specification information for specifying a combination of a first frame and a second frame obtained by demodulating the received OFDM signal; and a detection section adapted to detect a combination of a packet of the common packet sequence which configures the first frame and a packet of the data packet sequence which configures the second frame, whose combination is specified based on the acquired specification information.

Abstract: Methods, apparatuses, and computer program products are disclosed for facilitating decoding a communication received from a wireless terminal. Encoded bits are received from the wireless terminal via a shared uplink channel, and a plurality of acknowledgment tones are identified within the encoded bits. A correlation value is ascertained corresponding to a correlation between detected bits within the plurality of acknowledgment tones and valid bits corresponding to any of a plurality of valid acknowledgment codewords. A determination is then made as to whether the plurality of acknowledgment tones includes information corresponding to a discontinuous transmission by comparing the correlation value to a threshold value.

Abstract: The invention provides a method for frequency offset estimation according to a filtered signal with destroyed phase information. In one embodiment, a filter filters an original signal according to a series of first filter coefficients to obtain a first-channel component of the filtered signal, and filters the original signal according to a series of second filter coefficients to obtain a second-channel component of the filtered signal. A series of third filter coefficients are first derived from the first filter coefficients. The original signal is then filtered according to the third filter coefficients to obtain a reference signal. A first frequency offset value is estimated according to the first-channel component of the filtered signal and the reference signal, wherein the first-channel component of the filtered signal is a first-channel component of an artificial signal, and the reference signal is a second-channel component of the artificial signal.

Abstract: A wireless transmitter can include a plurality of bandwidth modules, each bandwidth module processing data based on a predetermined frequency band. In one embodiment, such a wireless transmitter can include encoding components for receiving transmit data and generating encoded data. A multiple-input multiple-output (MIMO) stream parser can receive the encoded data and generate a plurality of MIMO streams. A first module parser coupled to a first MIMO stream can generate a first plurality of partial MIMO streams. A first bandwidth module can include a first interleaver that interleaves bits of the first partial MIMO stream and generates first interleaved data. A second bandwidth module can include a second interleaver that interleaves bits of the second partial MIMO stream and generates second interleaved data. A first inverse fast Fourier transform (IFFT) unit can combine and process the first and second interleaved data and generate a first transmission MIMO stream.

Abstract: Embodiments of the present invention provide a system, method, and apparatus of adjusting a wireless communication signal. In some demonstrative embodiments the method may include, for example, allocating a plurality of spectral components to an adjustment signal based on a spectral range of the wireless communication signal to be adjusted by the adjustment signal, wherein one or more of the spectral components are included in the spectral range. Other embodiments are described and claimed.

Abstract: A multi-channel sequential Viterbi decoder includes: an input buffer, a “Read Data from Input Buffer” signal driver, a processing unit selector, a decoder channel parameters registers unit, a processing unit for a “Reset Path Metrics” command, a processing unit for a “Set Path Metric Value for the Given Path Number” command, a processing unit for a “Get Single Bit from the Path with Given Number” command, a processing unit for a “Process Input Samples” command, a memory for storing decoding paths and path metrics, a unit for generating an address for the memory, and data buffers for decoder channels output.

Abstract: The device is used for decoding convolution-encoded reception symbols. In this context, transmission data are modulated with a modulation scheme to form symbols, which are encoded with a transmission filter to form convolution-encoded transmission symbols. A convolution-encoded transmission symbol contains components of several symbols arranged in time succession. These transmission symbols are transmitted via a transmission channel and received as reception symbols. The Viterbi decoder decodes the reception symbols by use of a modified Viterbi algorithm. Before running through the Viterbi decoder, the reception symbols are processed by a state-reduction device, which determines additional items of information relating to possible consequential states of the decoding independently of the decoding through the Viterbi decoder in every state of the decoding. The state-reduction device uses the additional items of information to restrict the decoding through the Viterbi decoder to given consequential states.

Abstract: A system and method for non-uniform bit allocation in the quantization of channel state vectors is provided. A method for communications node operation includes receiving a bit-allocation profile for use in quantizing channel state information, measuring a communications channel between the communications node and a controller, generating channel state information based on the measurement, computing a bit representation of the channel state information, transmitting the bit representation to the controller, and receiving a transmission from the controller. The computing makes use of quasi-tail-biting trellis decoding, and the computing is based on the bit-allocation policy. The transmission makes use of the channel state information transmitted by the communications node.

Abstract: A method for suppressing interference in a wireless communication is provided. The method comprises receiving a burst of symbols, generating a plurality of timing hypotheses for the burst of symbols, and calculating, for each timing hypothesis, a plurality of weights for an interference suppression filter based upon a subset of the burst of symbols. The method further comprises, for each timing hypothesis, filtering the subset of the burst of symbols using the interference suppression filter with the corresponding plurality of weights, and selecting one of the plurality of timing hypotheses corresponding to a selection criteria. The method further comprises equalizing and decoding the filtered burst of symbols based upon the selected one of the plurality of timing hypotheses.

Abstract: An integrated circuit includes logic configured to encode pilot signals in a first set of subcarriers of an orthogonal frequency division multiplexing (“OFDM”) symbol and in a second set of subcarriers of a consecutive OFDM symbol. The symbol and the consecutive symbol are in the same smart-utility-network packet.

Abstract: A multiple antenna communication method and a multiple antenna communication system are provided. The multiple antenna communication method includes: determining a weighting vector with respect to a plurality of transmit antennas, using a spread spectrum code; determining a target transmission rate of each of the transmit antennas using the determined weighting vector; transmitting information associated with the target transmission rate to a multiple antenna reception apparatus; receiving, from the multiple antenna reception apparatus, channel information including information regarding whether to accept the transmitted target transmission rate information; and transmitting data to the multiple antenna reception apparatus using the received channel information.

Abstract: A method of detecting received data in a communication system includes the steps of: performing a QR decomposition on a received input vector as a function of one or more characteristics of a communication channel over which the input vector was transmitted; generating a subset of best symbol candidates from a symbol constellation by comparing an input sample (corresponding to an element of the input vector) with one or more prescribed thresholds; identifying at least one symbol satisfying prescribed minimum Euclidian distance criteria among multiple ambiguity symbols in the subset of best symbol candidates; and generating a subset of best symbols including a prescribed number of symbols from the symbol constellation determined to be closest to the input sample. The subset of best symbols is used in a subsequent iteration of the steps of generating the subset of best symbol candidates and identifying at least one symbol satisfying the prescribed minimum Euclidian distance criteria.

Abstract: A forward error correction encoding method includes: separating a first header section from an inputted packet stream; generating a second payload section by encoding a first payload section of the packet stream, from which the first header section is separated, according to a preset code rate; generating a second header section according to the code rate; and combining the first header section, the second header section, and the second payload section.

Abstract: A multi-tone transceiver with a components forming a transmit path and a receive path configured to couple via a subscriber line to an opposing multi-tone transceiver for frequency division multiplexed multi-tone modulated communications therewith is disclosed. A noise margin channel identifier is configured to identify within a received tone set, discrete tones each associated with a corresponding one of at least two channels differing from one another in a relative noise margin of associated tones. A Viterbi decoder is responsive to the channel identification provided by the noise margin channel identifier to discretely decode each of the at least two channels; thereby improving the fidelity of the error correction provided by the Viterbi decoder by discretely processing the identified channels within the received set of tones.

Abstract: An apparatus and method for transmitting digital broadcast signal are provided. The apparatus includes a group formatter to format a data group including mobile service data, where the group formatter further maps the mobile service data into a data group of interleaved format, adds N training sequences into a corresponding location of the data group of interleaved format, adds signaling data into the data group of interleaved format, inserts place holder bytes for MPEG header and non-systematic Reed-Solomon (RS) parity into the data group of interleaved format, and deinterleaves the mobile service data in the data group of interleaved format, a non-systematic RS encoder to non-systematic RS encode the mobile service data in the formatted data group and insert non-systematic RS parity obtained from the non-systematic RS encoding into the formatted data group.

Abstract: Methods, apparatuses, systems, and architectures for providing fast, independent, and reliable retrieval of system data (e.g., metadata) from a storage system, which enables minimal degradation in the reliability of user data. Methods generally include encoding the system data at least twice, at least once independently and at least once jointly along with user data. Methods can also include decoding the system data first, and upon a decoding failure, jointly decoding the system data and the user data.

Abstract: Methods and systems are disclosed for channel estimation and frequency tracking in mobile communication systems. Particularly, various ways of using the time domain impulse channel response based on the staggered frequency domain pilot tones are presented that enable rapid frequency error estimation and frequency tracking control. A mathematical model is developed that provides a convenient metric for evaluating tolerable frequency error, as well as modes for switching between channel impulse response (CIR)-based and secondary synchronization channel (SSC)-based frequency tracking.

Abstract: The present invention relates to a multi-antenna subsystem for a SDR (software defined radio) capable of supporting a multi-antenna technique to an antenna system using a multi-antenna subsystem. The multi-antenna subsystem of a multi-antenna system includes an algorithm executing unit for carrying out an algorithm for a multi-antenna technique to be required in the multi-antenna system, a frame synchronization unit for a synchronization acquisition, and a control unit for controlling the algorithm executing unit and the frame synchronization. The algorithm executing unit has a plurality of functional blocks and the functional block has state information, which can be referred by other functional blocks, for supporting SDR system.

Abstract: A method of estimating a channel response of a channel is provided that includes transforming a frequency domain signal received via the channel into a time domain signal and searching the time domain signal for a location of minimum energy. The method also includes padding the time domain signal with zeroes at the location of minimum energy and transforming the padded time domain signal to a second frequency domain signal. The second frequency domain signal is used as an estimated channel response for the channel.

Abstract: A receiving apparatus for receiving an orthogonal frequency division multiplexing (OFDM) signal including a frame having one frame length of a plurality of patterns. The apparatus comprises an acquiring section to acquire information regarding a preamble signal from an OFDM signal from a transmitting apparatus; a frame determining section to determine whether the one frame length is short in the frame based on the information regarding the acquired preamble signal; and a time interpolating section to obtain transmission path characteristics by comparing a pilot contained in the preamble signal with a known pilot corresponding to the pilot in a phase of transmission, when the frame determining section determines that the one frame length is short in the frame, and to interpolate a data portion in a time direction based on transmission path characteristics.

Abstract: A closed-form parametric approach to channel-estimation is provided. In one aspect, a specific parametric expression is presented for the received signal pdf that accurately models the behavior of the received signal in IM/DD optical channels. The corresponding parametric channel-estimation approach simplifies the design of MLSE receivers. The general technique lends itself well to the estimation of the signal pdf in situations where there are multiple sources of noise with different distributions, such as ASE noise, together with Gaussian and quantization noise, and signal-dependent noise, for example.

Abstract: In cable modem termination systems (CMTS) and other information transmission systems, a method for changing the interleave depth associated with each data stream is provided. This may be done dynamically, and for any subset of downstream devices such as modems. The interleave depth may be set on an individual device level. Embodiments may decrease data receiving latency on devices that do not suffer from error rates, such as caused by burst noise, while maintaining throughput on devices with high error rates.

Abstract: In one embodiment, a method to generate a set of tone frequencies within an operating frequency range for use in a timing acquisition process in a wireless communication system comprises selecting a system frequency resolution generating a set of frequency tones which are relatively prime integers with respect to the frequency resolution and within an operating frequency range of the wireless communication system. Other embodiments may be described.

Abstract: A soft symbol decoder for use in a multiple input multiple output (MIMO) and OFDM (orthogonal frequency division multiplexing) system. The decoder generates soft symbol values for a digital signal that represents a number of source bits. The source bits are transmitted as symbols in corresponding to points in a signaling constellation. Soft metrics are determined by searching for all possible multi-dimensional symbols that could have been transmitted. The method includes transmitting a sample of the multi-dimensional symbol using K transmit antennas. The multi-dimensional symbol is represent-able as a complex, K-dimensional vector x. Each vector component of vector x represents a signal transmitted with one of the K transmit antennas. After transmission through a communication channel, a sample corresponding to the transmitted sample is received. The received sample is represented by a complex, N-dimensional vector y, where N is the number of receive antennas in the MIMO system.

Abstract: There is provided a wireless apparatus in which a distortion compensation loop is formed so as to compensate nonlinear distortion of a transmission amplifier, being used on a time division duplex system on which a wireless signal is transmitted in a transmission time period with same frequency as being received, the wireless apparatus used on the time division duplex system including a combining section to combine a feedback signal into which a return signal generated by reflection of a transmission signal at a antenna leaks and the return signal processed by a reception unit to process a reception signal from the antenna in the transmission time period so as to cancel the return signal leaked into the feedback signal.