Estimating transmit symbol vectors transmitted in an overloaded communication channel includes receiving a signal represented by a received signal vector, the received signal vector corresponding to a superposition of signals representing transmitted symbols selected from a constellation of symbols and transmitted from one or more transmitters.

A processing method in a wireless telecommunications receiver receiving a digitally modulated single-carrier signal includes, between a matched filter, in the time domain, operating at a frequency drx×B and a frequency equalizer, operating at the frequency B, a decimation step comprising: i/extracting, from a filtered signal frame, a first sequence of samples for aiding the decimation and having the same power; and a second sequence of payload samples intended to be equalized; ii/estimating the variance in the power of each of the drx decimation phases of the first sequence and identifying the n.sup.th decimation phase associated with the minimum variance; iii/decimating the second sequence by selecting the n.sup.th decimation phase of the second sequence and supplying the decimation phase at the input of the frequency equalizer.

A relay device relaying, to a reception device, a signal stream transmitted by a transmission device through MIMO transmission, the relay device including a lattice base reduction processing unit transforming bases of the signal stream transmitted by the transmission device through MIMO transmission, to increase orthogonality of a lattice of the signal stream, a MIMO equalization unit detecting, by equalization, reception symbols in the signal stream with the bases transformed by the lattice base reduction processing unit, a symbol quantization unit performing quantization by mapping the reception symbols detected by the MIMO equalization unit, to a region on a complex plane delimited by quantization threshold values, and a transmission unit transmitting, to the reception device, at least a signal quantized by the symbol quantization unit.

A computer-implemented method of estimating transmit symbol vectors transmitted in an overloaded communication channel includes receiving a signal represented by a received signal vector, the received signal vector corresponding to a superposition of signals representing transmitted symbols selected from a constellation of symbols and transmitted from one or more transmitters. Continuous first and second functions in a search space in a convex domain are defined. The first function and the second function are combined into a third function, and a fractional programming algorithm is applied to the third function, targeted to finding an input vector that minimizes the third function. A mapping rule translates the found input vector into an estimated transmit symbol vector, and the estimated transmit symbol vector is output to a decoder for decoding into an estimated transmit symbol from the constellation.

A method for estimating a signal-to-interference-plus-noise ratio at a receiver of a wireless communication system OFDM signals may include: determining an estimate ŝ.sub.serving of the signal power of a serving cell of the communication system based on the channel impulse response estimated for the serving cell, determining an estimate ŝ.sub.interfering of the signal power of one or more interfering cells of the communication system based on the channel impulse response estimated for the one or more interfering cells, and determining an estimate of the SINR based on the determined estimate of the signal power of the serving cell and the determined estimate of the signal power of the one or more interfering cells. A Method for equalization of received symbols at a receiver of a wireless communication system using OFDM signals may include: determining an equalizer filter and applying the equalizer filter onto the received signal for equalization of the signal, wherein the equalizer filter is determined in the time domain based on an estimated channel impulse response, an estimated noise covariance and an estimated received symbol covariance.

The present disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as a long term evolution (LTE). A method for receiving data includes selecting one of reception schemes, and receiving data based on the selected reception scheme, wherein the reception schemes includes a scheme of determining an integer matrix based on channel values estimated for channels, and decoding symbols received through the channels based on the determined integer matrix, and a scheme of detecting, for each channel, a sum of symbols received from each of the channels during a preset time based on integer matrixes which are determined based on each of the channel values, retransforming the sum of the symbols detected for each channel based on at least one of the integer matrixes, and decoding the retransformed sum of the symbols for each channel.

A transmitter may comprise a symbol mapper circuit and operate in at least two modes. In a first mode, the number of symbols output by the mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter may be greater than the number of data-carrying subcarriers used to transmit the OFDM symbol. In a second mode, the number of symbols output by said mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter is less than or equal to the number of data-carrying subcarriers used to transmit said OFDM symbol. The symbols output by the symbol mapper circuit may be N-QAM symbols. While the circuitry operates in the first mode, the symbols output by the mapper may be converted to physical subcarrier values via filtering and decimation prior to being input to an IFFT circuit.

Methods, systems, and computer program products for decoding a received data signal in a communication system by iteratively constructing a decoding tree, each node of said decoding tree corresponding to a component of a symbol of said data signal, and being associated with a metric, the construction of the decoding tree implementing at least one iteration of the following steps, for a current node of the tree stored in the top of a stack: generating (102) a reference child node of said current node from said vector representing the received data signal, from the reference child node, generating (106) a first neighbor child node by subtracting a positive integer parameter from the value of the reference node, and a second neighbor child node by adding said positive integer parameter to the value of the reference child node; storing (108) in said stack three child nodes deriving from the reference child node and from said first and second neighbor child nodes, each child node being stored in the stack in association with node information comprising a predetermined metric, the nodes in the stack being ordered by increasing values of metrics; removing (109) the current node from said stack; selecting (111) the top node of said stack as the new current node;
wherein said method further comprises determining an estimation of said data signal from the node information stored in said stack.

A decoder for determining an estimate of a vector of information symbols carried by a signal received through a transmission channel represented by a channel matrix is provided. The decoder includes a block division unit configured to divide the vector of information symbols into two or more sub-vectors, each sub-vector being associated with a block level; two or more processors configured to determine, in parallel, candidate sub-vectors and to store the candidate sub-vectors in a first stack. Each processor is configured to determine at least a candidate sub-vector by applying a symbol estimation algorithm and to store each candidate sub-vector with a decoding metric and the block level associated with the candidate sub-vector. The decoding metric is lower than or equal to a decoding metric threshold. A processor among the two or more processors is configured to determine at least a candidate vector from candidate sub-vectors stored in the first stack, the candidate vector being associated with a cumulated decoding metric and to update the decoding metric threshold from the cumulated decoding metric.

The present disclosure relates to a demodulation method, apparatus, and device. Some embodiments of the present disclosure are beneficial to improving demodulation performance.