Abstract: The disclosure provides a channel decoding method and a tail biting convolutional decoder. The method comprises: the tail biting convolutional decoder performs add-compare-select processing on metric values of 2N states according to input data to be decoded and N zeros input after the data to obtain final cumulative metric values of the 2N states, and stores selection result of add-compare-select processing, wherein N is the constraint length of tail biting convolutional coding; the tail biting convolutional decoder starts to backtrack from one state of the 2N states according to the selection result to obtain intermediate decoding result after the add-compare-select processing is finished; the tail biting convolutional decoder outputs the bits except the last N bits of the intermediate decoding result as decoded result of the data to be decoded. The tail biting convolutional decoder comprises an add-compare-select module, a backtracking module and an outputting module.

Abstract: Demodulation methods and apparatus for a multi-stage SLI demodulator are disclosed. Residual signals from each demodulation stage are modeled as finite sets of unresolved signals and a new metric is introduced for use in search of best candidate symbol estimates. The metric may be evaluated based on a probability distribution function of the residual signals or a probability mass function of the unresolved signals. The metric may also be approximated by the sum of a conventional Euclidean metric and a correction metric. The best candidate symbol estimates generated from each stage of the multi-stage SLI demodulator are summed to form cumulative symbol estimates.

Abstract: According to one embodiment, a scaling decision device includes a first decision unit and a second decision unit. The first decision unit decides, based on a plurality of input signals, a K-th smallest signal of the plurality of input signals or a range to which the K-th smallest signal belongs of a plurality of ranges which classify the plurality of input signals by intensities. The second decision unit decides, based on a decision result of the first decision unit, a scaling value which prevents the K-th smallest signal from being submerged in quantization errors by normalization.

Abstract: A blanking scheme for mitigating impulsive noise in wireless networks is based on the signal-to-noise ratio (SNR) of symbols. To fully gain the benefits of the SNR-based blanking scheme, two methods are developed, namely a multi-level thresholding scheme in the time-, spatial- and frequency-domains, and a weighted-input error-correction decoding. The symbols are conditioned as a function of the estimated SNR in time-, frequency-, or spatial-domains or combinations therefore, and the conditioning is applied to an amplitude, phase, or energy level, or combinations thereof.

Abstract: A receiving device according to the present invention includes: a receiver for receiving an OFDM symbol that is modulated by phase shift keying; an FFT processor for applying an FFT process to the received OFDM symbol to obtain a subcarrier signal; a demapping unit for demapping the subcarrier signal to generate a bit string; a norm calculator for calculating the norm of the subcarrier; a weighting factor generator for generating a weighting factor by taking the statistics of the calculated norm; and a weighting unit for obtaining a soft decision value by weighting the bit string after demapping, based on the particular weighting factor. Thus, the receiving device can obtain a soft decision value to achieve good decoding performance with a small number of known signals and processes.

Abstract: A method of estimating log-likelihood ratios for first and second streams of samples of a received S-FSK signal demodulated using first and second carriers includes estimating channel and noise parameters associated with first and second transmitted values for the first and second streams of samples obtained from the received S-FSK modulated signal. Current signal-to-noise ratios are estimated for current samples of the first and second streams of samples obtained from the received S-FSK modulated signal using the channel and noise parameters. The estimated current signal-to-noise ratios are compared with values of a discrete ordered set and respective pairs of consecutive values of the discrete ordered set between which the estimated current signal-to-noise ratios are comprised are identified. Log-likelihood ratios are estimated for the current samples of the first and second streams.

Abstract: An improved mapping policy, signal mapper, transmitter, receiver, and communication system are introduced. The improved signal mapping policy alternates between standard and inverted bit mapping functions at selected phase states to reduce the error coefficient of MSK and other types of CPFSK signals. The proposed policy can more generally be applied to other types of signals with memory as well. Simulations show that the mapping policy can significantly improve performance particularly at lower to moderate SNR values.

Abstract: A signal demultiplexing method and apparatus are provided, for determining a likelihood of each bit included in a second signal, which is spatially multiplexed with and received with a first signal, based on a maximum likelihood detection (MLD) method using QR decomposition, wherein the first signal excludes the second signal to be calculated only in a final stage of the MLD method.

Abstract: A receiver system and method for recovering information from a symbol data sequence Y. The symbol data sequence Y corresponds to a symbol data sequence X that is transmitted onto the channel by a transmitter. The symbol data sequence X is generated by the transmitter based on associated information bits. At the receiver, a set of two or more processors operate in parallel on two or more overlapping subsequences of the symbol data sequence Y, where each of the two or more overlapping subsequences of the symbol data sequence Y corresponds to a respective portion of a trellis. The trellis describes redundancy in the symbol data sequence Y. The action of operating in parallel generates soft estimates for the associated information bits. The soft estimates are useable to form a receive message corresponding to the associated information bits.

Abstract: Time filtering channel estimates in a wireless communication system, such as an Orthogonal Frequency Division Multiplex (OFDM) system, can be used to improve the quality of channel estimates. The characteristics of an optimal channel estimate time filter can depend on the manner in which the channel estimate is determined as well as the time correlation of channel estimates. A receiver can implement an adaptive time filter for channel estimates in which the time filter response can vary based on channel estimate parameters. The channel estimate parameters can include the manner of determining channel estimates, a time correlation of channel estimates, and an estimated Doppler frequency. The time filter response can be varied continuously over a range of responses or can be varied discretely over a predetermined number of time filter responses.

Abstract: Two decoding algorithms are introduced for the decoding of multi-level coded modulation and other types of coded modulation involving component codes and interleaving operations. An improved hard iterative decoding (IHID) algorithm is presented that improves upon a hard iteration decoding technique by adding a stopping criterion. Also, a list Viterbi hard iteration decoding (LV-IHID) algorithm is presented that employs list decoding in conjunction with the IHID algorithm. Both of these decoding algorithms improve upon conventional multi-stage decoding by reducing the effective error multiplicity that is observed at the lowest coding level. It is demonstrated that the LV-IHID algorithm performs close to soft iterative decoding. The computational and delay complexity of the proposed decoding algorithms compare favorably with soft iterative decoding strategies. Also, a novel labeling strategy for MLC design is presented.

Abstract: A method for QR-maximum likelihood detection (QR-MLD) demodulation is provided. The method includes determining a transmission reception mode, receiving symbols represented by a received symbol vector, generating a channel matrix, and performing QR decomposition on the channel matrix to compute a unitary matrix and an upper triangular matrix. The method further includes the steps of processing the received symbol vector by multiplying the received symbol vector by the Hermitian of the unitary matrix, determining whether a conjugate calculation will be required to set a conjugate flag, computing a first distance metric by performing a conjugate or non-conjugate first distance metric calculation depending on the conjugate flag, and computing an estimated symbol by performing a conjugate or non-conjugate estimated symbol calculation depending on the conjugate flag.

Abstract: A technique for decoding a signal in a communication network is provided. A method implementation of the technique comprises the steps of receiving a signal; identifying a position in the signal; initializing a Viterbi state metric; and decoding the encoded signal by means of a wrap-around Viterbi algorithm. The received signal comprises information, wherein the signal is encoded by a tail-biting convolutional code. The identified position relates to a known portion of the information. The initialized Viterbi state metric is consistent with the known portion of the information. The decoding uses the initial Viterbi state metric, wherein the decoding starts at a decoding step following the identified position.

Abstract: Interference in a received orthogonal frequency division multiplexing (OFDM) symbol, modulated according to selected constellation points Sk, is reduced. The symbol includes a set of pilot signals and a set of data signals yk, where k is a number of consecutive subcarriers used for the pilot and the data signals. The pilot signals are thresholded to detect interfering pilot signals, which are then erased. Channels ?k are estimated using remaining pilot signals. The set of data signals are decoded based on the estimated channels ?k, and, for each bit bi in the set of data signals, a logarithmic likely ratio (LLR) log ? ? s k : b i = 0 ? 1 ? y k - H ^ k ? s k ? 2 ? s k : b i = 1 ? 1 ? y k - H ^ k ? s k ? 2 is determined. The LLR is an indicator of the likely interference.

Abstract: A method is provided for soft-decision sphere decoding for softbit computation which can be applied to all sphere decoding algorithms, in particular sphere decoding algorithms in any MIMO OFDM receiver implementations. Complexity reduction is achieved by using an approximate of linear Euclidean distances during the sphere decoding search. The method can be used in conjunction with MIMO OFDM communication systems like LTE, WiMax and WLAN.

Abstract: A plurality of received data symbols is received, and a first received data symbol is selected from the plurality of received data symbols. A plurality of global optimum candidate values of a first estimated transmitted data symbol corresponding to the first received data symbol is determined for different given candidate values of second estimated transmitted data symbols corresponding to second received data symbols. Likelihood values for bits corresponding to the second estimated transmitted data symbols are calculated using the plurality of global optimum candidate values. All possible values of the first estimated transmitted data symbol are grouped into two or more bit groups, and a plurality of local optimum candidate values are determined for different bit groups. Likelihood values for bits corresponding to the first estimated transmitted data symbol are calculated using the plurality of global optimum candidate values and the plurality of local optimum candidate values.

Abstract: A system includes a channel estimator configured to receive a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols via a plurality of respective antennas, and generate estimates of a channel based on the plurality of OFDM symbols. A demodulator is configured to generate a plurality of demodulated symbols based on the plurality of OFDM symbols and the estimates of the channel. A decoder is configured to receive the estimates of the channel from the channel estimator, receive the plurality of demodulated symbols from the demodulator, and calculate decision metrics for the plurality of OFDM symbols using both the estimates of the channel and the plurality of demodulated symbols.

Abstract: A technique for processing information in a wireless communication network is described. In a method in accordance with the technique, a signal encoded with a convolution code is received. The encoded signal comprises information and a check value. The encoded signal is decoded using a Viterbi algorithm to derive the information and the check value. The decoding includes computing a Viterbi state metric. A reliability parameter is then determined based on the Viterbi state metric. The information is selectively processed depending on both the check value and the reliability parameter.

Abstract: A receiver includes a constellation processing module and a multi-stage demodulator having a plurality of non-final demodulation stages and a final demodulation stage. The constellation processing module derives a set of centroid-based values from subsets of constellation points associated with a plurality of transmitted signals for input to each of the non-final demodulation stages. Each of the non-final demodulation stages demodulates a group of signals input to the non-final demodulation stage using the set of centroid-based values as constellation points and suppresses residual interference associated with using the set of centroid-based values as constellation points for signal demodulation. The final demodulation stage demodulates a group of modified signals input to the final demodulation stage using the subset of constellation points input to the final demodulation stage to determine a final symbol decision for the plurality of transmitted signals.

Abstract: A process for computing Log-Likelihood-ratios (LLR) in a detector of a wireless communication receiver, said LLR being used by a channel decoder. The process comprises the steps of:—receiving a signal from a telecom front end, said signal corresponding to data belonging to a finite set of constellation symbols, each constellation symbol being arranged in a lattice constellation impaired by an additive noise and also by a multiplicative channel; —computing a limited set of distances representative of the Euclidian distances between the received signal and a finite set of predetermined constellation symbols, possibly multiplied by the channel; —deriving a set of soft decisions or LLR from said computed set of distances under the constraint of a limited length of the list of distances, and —completing said derived LLR by clipping values read from a look-up table which is simultaneously addressed by the values of the SNR and the bit index.

Abstract: In various aspects, the disclosure describes systems and methods for decoding of convolutionally encoded signals representing, for example, telecommunications signals such as command or content signals used in digital telecommunications. In various embodiments such aspects of the disclosure provide systems and methods for improving the efficiency, speed, and power consumption of such processes by providing architectures and methods for processing various parts of the encoded data records in parallel, using multiple and optionally specially-designed, dedicated memory registers and multiplexers.

Abstract: An embodiment of the present invention is a technique to process signals in a communication system. A channel impulse response (CIR) generator generates a time-domain windowed CIR from a received signal using a window function. A thresholder thresholds the time-domain windowed CIR. A compensator compensates window effect for the thresholded time-domain windowed CIR to provide an enhanced channel estimate in frequency domain.

Abstract: A method applies channel status information (CSI) to a soft-decided signal. The method performs adjustment suitable for a soft-decided and received signal in applying pre-estimated CSI to a decoder, thereby enhancing performance and enabling adaptive application. The method includes calculating a second value CSINEW for enhancing reliability of a received first CSI CSIRECEIVED, and applying a weight value to the calculated second CSI value CSINEW to calculate a third CSI value CSIWEIGHTED; applying the third CSI value CSIWEIGHTED to a first soft-decision value SSOFTDECISION of an actually-received signal to calculate a second soft-decision value SSOFTDECISION+CSI adjusted; and restrictedly controlling an output range of the calculated second soft-decision value SSOFTDECISION+CSI to obtain a third soft-decision value SSOFTDECISION+CSI—Bounded.

Abstract: Provided is an encoding device which divides an input signal into a low-range component and a high-range component and encodes the components in separate encoding units. The encoding device can improve quality of a decoded signal.

Abstract: Disclosed is a phase error estimating an apparatus and a method which provides improved convergence speed and tracking speed even in mobile channel environment by variably applying the step size for phase error estimation according to channel status. The apparatus for estimating a phase error includes: a posterior probability (APP) average calculating unit for calculating an APP average value from a soft decision result of a currently received symbol; a step size determining unit for determining a step size variably according to channel status; and a phase error estimating unit for estimating a phase error of the currently received symbol from a phase error of a previously received symbol and the APP average value by using the variably determined step size.

Abstract: Provided is a multi-antenna transmission device (400) which can perform MLD by using a simple configuration of a reception device in a MIMO-AMC system. The multi-antenna transmission device (400) includes common signal point mapping units (401, 402) for mapping data transmitted from different antennas (111, 112) in transmission scheme using MIMO spatial multiplexing, to common signal points shared by respective modulation methods. Thus, the arrangement of baseband signal points obtained by mapping a code word after channel encoding onto an IQ plane can be shared as common signal points shared by modulation methods. Accordingly, the reception device need not prepare a particular circuit for performing MLD calculation in accordance with a combination of the methods for modulating the signals which have been MIMO-space multiplexed. This can reduce the circuit size of the MLD calculation circuit.

Abstract: A discrete cosine transform (DCT)-based orthogonal frequency-division multiplexing (OFDM) system is provided with a zero-padding guard interval and MMSE reception. The performance of the DCT-OFDM system with the zero-padding guard interval scheme and the minimum mean-square error (MMSE) receiver over time-varying multipath Rayleigh fading channels is investigated. The results show that employing the proposed DCT-OFDM system rather than the conventional DFT-OFDM system can provide better bit error rate performance in practical systems, by as much as 6 dB in signal-to-noise ratio.

Abstract: The present invention is directed to a transmitter and method for transmitting data in a digital communication system, the method comprising generating an original symbol by mapping the bits of the original bit sequence using a modulation constellation, generating at least one counter part symbol from the original symbol or from at least one counter part bit sequence generated from the original bit sequence where a combination of the original symbol and the at least one counter part symbol forms a quasi pilot symbol.

Abstract: A method of demodulating a modified dual carrier modulation (MDCM) signal using hard decision includes generating real symbol vector candidates and imaginary symbol vector candidates which correspond to an MDCM signal pair; calculating a first norm between a real part of the MDCM signal pair and each of the real symbol vector candidates and determining as a real symbol vector a real symbol vector candidate that has the minimum first norm among the real symbol vector candidates; and calculating a second norm between an imaginary part of the MDCM signal pair and each of the imaginary symbol vector candidates and determining as an imaginary symbol vector an imaginary symbol vector candidate that has the minimum second norm among the imaginary symbol vector candidates.

Abstract: In one embodiment, a wireless device for a wireless data communication system including the wireless device and a base station. The base station includes a plurality of first groups and a signal-processing unit. Each first group includes a receiver and at least one antenna connected to the receiver. The signal-processing unit includes memory and a processor adapted to process signals received by the first groups using a Maximum Likelihood Detection (MLD) method. The wireless device includes a plurality of second groups, each second group adapted to transmit a wireless signal to at least one first group via a corresponding communication channel. Each second group further includes a transmitter and at least one antenna connected to the transmitter.

Abstract: An iterative detection and decoding device includes a signal detector, an error-correction decoder and an SI selector. The signal detector is utilized for generating a set of soft information (SI). The error-correction decoder is coupled to the signal detector, for iteratively decoding the set of SI and accordingly updating the set of SI to generate a set of updated SI. The SI selector is coupled between the signal detector and the error-correction decoder, for selecting at least one SI from the set of updated SI when each SI satisfies at least one predetermined constraint rule. The signal detector further selectively generates a new set of SI according to a selection result generated from the SI selector.

Abstract: Methods for coherent and non-coherent demodulation are disclosed. Embodiments herein relate to wireless communication systems, and more particularly, to demodulating block orthogonal codes in wireless communication systems. Coherent detection of signals provides improved performance at higher complexity of implementation, but it can be difficult to keep the frequency errors in a wireless communications receiver within the required limits for coherent detection. Embodiments disclosed enable means of using coherent demodulation for block orthogonal codes in the presence of high frequency errors, through the use of techniques of frequency prediction, estimation and correction. Further, it enables a low complexity frequency estimator which provides high estimation range and accuracy.

Abstract: An information reproduction apparatus includes a generator of a channel clock synchronized to input data, an analog/digital converter for converting the input data with an 1/N clock which is in frequency one Nth (N: a positive real number) of the channel clock, and a Viterbi decoder including a unit for calculating a branch metric based on a difference between an output of the converter and a reference value, an ACS unit responsive to input of data corresponding to one time point of the 1/N clock, for adding the branch metric for one time point to an old path metric, comparing addition results, selecting a smaller result, and outputting a new path metric and a path selection signal, according to state transitions with N bits as a unit, a unit for determining a maximum likelihood path based on the selection signal, and a decoder for outputting a decoding result.

Abstract: A base station includes a reference signal generator, a boost selector, and a transmitter. The reference signal generator provides a dedicated reference signal to be transmitted over a plurality of antennas to a dedicated user device. The boost selector selects a dedicated boost level that is specific for the dedicated reference signal. The boost selector applies the dedicated boost level to the dedicated reference signal and not to a data signal to be transmitted to the dedicated user device. The boost selector generates a boosted dedicated reference signal. The transmitter transmits the boosted dedicated reference signal and the data signal to the dedicated user device after beamforming weights are applied to the boosted dedicated reference signal and to the data signal.

Abstract: A system and method for the quantization of channel state vectors is provided. A method for communications node operation includes 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 tail-biting trellis decoding, and the transmission makes use of the channel state information transmitted by the communications node.

Abstract: In a method for decoding plurality of information streams corresponding to a plurality of layers, where the plurality of information streams have been transmitted via a multiple input multiple output (MIMO) communication channel, a plurality of received signals are processed to decode information corresponding to a first layer. A plurality of modified received signals are generated using the decoded information corresponding to the first layer and the plurality of received signals. Bit metric values are generated for a second layer using MIMO maximum likelihood (ML) demodulation and using the plurality of modified received signals and channel and modulation information for interfering signals. Information corresponding to the second layer is decoded using the generated bit metric values.

Abstract: A method and an apparatus for modulation recognition in communication system are provided. First, a plurality of constellation corresponding different modulation types are provided, wherein each constellation has a plurality of points. An input signal is de-mapped to find out a nearest point located nearest to a position of the input signal in each constellation. The distances from the nearest points to the position of the input signal are respectively counted to obtain a plurality of distance statistics values corresponding to different modulation types. The apparatus compares the distance statistics values for recognizing the modulation type of the input signal.

Abstract: A Tu delay section (110) delays an analog-to-digital converted OFDM signal S01 by a time corresponding to an effective symbol period Tu. A correlation signal of an output of the Tu delay section (110) and OFDM signal S01 is obtained using a correlation calculating section (120). A delay section (130) outputs at least one delayed correlation signal obtained by delaying a correlation signal S02. Next, an adding section (140) performs addition of the correlation signal S02 and the delayed correlation signal, and then an interval integration section (150) performs transfer integration over a definite interval on a result of the addition. Then, a symbol period smoothing section (160) smoothes a result of the transfer integration for an interval of the effective symbol period of the OFDM signal S01, and then a window position detection section (170) calculates window position information from an output of the symbol period smoothing section (160).

Abstract: A channel decoder including an amplifier configured to amplify a signal; a first summer configured to generate an output signal based on the signal amplified by the amplifier; and a Viterbi detector module configured to, based on the output signal, generate a first estimate signal and a second estimate signal, wherein the first estimate signal and the second estimate signal respectively indicate an estimate of data in the signal. The channel decoder further includes a second summer configured to generate a first error signal indicating a first gradient based on the first estimate signal; and a third summer configured to generate a second error signal indicating a second error gradient based on the second estimate signal. The first summer is configured to generate the output signal based on (i) the first error signal and (ii) the second error signal.

Abstract: A mobile station (MS) includes an estimation module, a filter module, and a filter selection module. The estimation module receives an input signal having subcarriers and generates first channel estimates based on the input signal. The subcarriers are selectively used by a base station (BS) to transmit preamble sequences when communicating with the MS. The filter module includes first and second filters. One of the first and second filters selectively filters the first channel estimates and generates second channel estimates. The filter selection module selects the one of the first and second filters based on a number of the subcarriers used to transmit the preamble sequences.

Abstract: Schemes for creating a surplus of decoding iterations in a decoder are described. The surplus can be used to augment the decoding of signal blocks. The option of using an idle decoder to decode blocks marked as unproductive for decoding is also described.

Abstract: Flexible rate matching. No constraints or restrictions are placed on a sending communication device when effectuating rate matching. The receiving communication device is able to accommodate received transmissions of essentially any size (e.g., up to an entire turbo codeword that includes all systematic bits and all parity bits). The receiving communication device employs a relatively small-sized memory to ensure a lower cost, smaller sized communication device (e.g., handset or user equipment such as a personal wireless communication device). Moreover, incremental redundancy is achieved in which successive transmissions need not include repeated information therein (e.g., a second transmission need not include any repeated information from a first transmission). Only when reaching an end of a block of bits or codeword to be transmitted, and when wrap around at the end of such block of bits or codeword occurs, would any repeat of bits be incurred within a later transmission.

Abstract: Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors based on the same transmitted vector. The symbols of the received signal vectors are combined, forming a combined received signal vector that may be treated as a single received signal vector. The combined received signal vector may be equalized by, for example, a zero-forcing or minimum-mean-squared error equalizer or another suitable linear equalizer. Following equalization, the equalized signal vector may be decoded using a simple, linear decoder.

Abstract: In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. The receiver performs code-averaged equalization and chip chip-level code-specific interference over-cancellation on the received signals. This can result in a unified interference cancellation processing, and can avoid cumbersome calculations of code cross correlations that is required in symbol-level interference cancellation. A symbol-level code-averaged desired signal add-back is performed to address the over-cancellation of some desired signals.

Abstract: A transmitted signal estimate based on signals received in a layer i within a multiple input, multiple output transmission system and based upon selected constellation points for other, previously processed layers is quantized to a nearest constellation point. A list of candidates headed by the nearest constellation point and with remaining candidates presorted by proximity to the head is selected, for each such quantized estimate based on constellation point selections for previously processed layers. To select K best candidates for the transmitted signal estimates of the current layer i, the proximity of the candidates at the head of each list to the signal estimate for the current layer are compared, and the closest candidate is selected. The list containing the selected candidate is advanced, and proximity of the transmitted signal estimate to all list heads is again evaluated and the closest candidate selected.

Abstract: A method and system for processing LLRs, in a receiver, of transmissions over a wireless telecommunication system, the method including receiving multiple soft symbols, selecting a set of appropriate instructions for LLR calculation for the soft symbols, arranging the soft symbols in a register of a processor according to the selected instructions, selecting an appropriate single instruction from the set of instructions to be implemented by the processor using the soft symbols in the register as operands, and calculating, by a computation unit, multiple LLR values for the multiple soft symbols, in parallel, by means of the selected instruction.

Abstract: Systems and methods for performing joint demodulation using a Viterbi equalizer having an adaptive total number of states are disclosed. Generally, a method includes joint demodulating a desired signal and one or more interfering signals with a Viterbi equalizer having an adaptive total number of states based on channel impulse response (CIR) coefficients associated with a desired signal and the one or more interfering signals.

Abstract: A method and device for compensating for undesirable signal characteristics such as baseline wander that includes a linear equalization filter responsive to receive an input, a combiner responsive to an output of the linear equalization filter, and a decision feedback equalization filter responsive to an output of the combiner, where the combiner is further responsive to an output of the decision feedback equalizer. Additionally, an error feedback circuit is responsive to the output of the combiner, and the combiner is further responsive to an output of the error feedback circuit to form a compensated signal having reduced distortion relative to the distorted signal.

Abstract: Provided is a method and apparatus for receiving a signal for a MIMO system. The receiving apparatus includes: a QR decomposer for calculating a unitary matrix Q, an upper triangle matrix R, and a vector size for a received signal; a multiple dimension detector for calculating a first LLR for an output of the QR decomposer through multiple dimension detection; an inverse matrix and weight calculator for calculating an inverse matrix for the upper triangle matrix R and a weight; an interference remover for regenerating a symbol for a demodulated data stream using the fist LLR and removing interference from an output vector of the QR decomposer using the regenerated symbol; and a weight zero forcing unit for performing zero forcing on the interference removed output vector from the interference remover using the inverse matrix of the upper triangle matrix R and the weight and calculating a second LLR.

Abstract: A Viterbi decoder includes a survival memory unit, for storing a plurality of survivor metric into a writing column of a writing bank of a plurality of banks in alternating intervals of a clock according to a writing bank order and a writing column order, and a trace back unit, for reading a reading column of each bank not performing storing operations according to a reading bank order and a reading column order in every interval of the clock.