Embodiments of the invention provide a decoder for decoding a signal received through a transmission channel in a communication system, said signal comprising a vector of information symbols, wherein the decoder comprises: a processing unit (307) configured to determine at least one candidate set of division parameters and to perform a division of said vector of information symbols into a set of sub-vectors in association with each candidate set of division parameters, each pair of sub-vectors being associated with a division metric; a selection unit (309) configured to select one of said candidate sets of division parameters according to a selection criterion depending on said division metric; and a decoding unit (311) configured to determine at least one estimate of each sub-vector associated with said selected set of division parameters by applying a symbol estimation algorithm,
wherein the decoder is configured to determine at least one estimate of the vector of information symbols from said at least one estimate of each sub-vector of information symbols.

A wireless system, and particularly, a multiple-input multiple-output (MIMO) wireless communication system is disclosed. The wireless system includes a plurality of (re)configurable antennas and a rate-two space coding design for a MIMO system. The MIMO wireless communication system generally includes M (re)configurable antennas configured to independently transmit or broadcast wireless electromagnetic signals having a frequency in the microwave and/or optical ranges, a controller configured to control the (re)configurable antennas, and an encoder configured to encode information onto the wireless electromagnetic signals. The information comprises codewords having N symbols, and the codewords are expressed in an NM matrix having a non-zero determinant and in which at least one symbol is associated with a coefficient configured to maximize diversity, maximize coding gain and/or reduce channel fading in the MIMO wireless communication system. M and N are each independently an integer of at least 2.

Apparatuses, methods, and systems for precoding multi-carrier signals are disclosed. One method includes obtaining a transmission channel matrix between a terminal and a plurality of separate users, wherein the transmission channel matrix includes channel estimates for a plurality of subcarriers of the multi-carrier signal, wherein the terminal is one of a plurality of terminals interfaced with a central processing unit, and wherein the terminal communicates with the plurality of spatially separate user with the multi-carrier signals. The method further comprises determining a precoding for the terminal based on a distribution of user signal power across the transmission channel between the terminal and the plurality of spatially separate user, and determining a precoding for the central processing unit based on the precoding for the terminal and based on the transmission channel matrix, wherein a precoding matrix for the central processing unit is multi-carrier signal dependent.

A method and apparatus for transmitting using beam are disclosed. A wireless transmit/receive unit (WTRU) may transmit a first physical random access channel (PRACH) preamble to a base station using a first beam at a first power level. The WTRU may receive an indication that the first PRACH preamble was received by the base station. If the indication was received, the WTRU may transmit data. If the indication was not received, the WTRU may select the first beam or a second beam to use for a second PRACH preamble. Further, the first and second beams may be different beams. If the first beam is selected, the WTRU may increase a transmission power level of the second PRACH preamble by a first power ramp step. If the second beam is selected, the WTRU may not increase the transmission power level of the second PRACH preamble by the first power ramp step.

A method for transmitting a signal in a communication system includes transmitting a signal using pre-generated matrix, wherein the pre-generated matrix is generated by repeating one matrix including zero elements by a predetermined number of times and a particular sequence is allocated to non-zero elements included in the pre-generated matrix. An apparatus for receiving a signal in a communication system includes at least one processor configured to make a control to receive a transmitted signal based on a pre-generated matrix and to receive the signal, wherein the pre-generated matrix is generated by repeating one matrix including zero elements by a predetermined number of times and a particular sequence is allocated to non-zero elements included in the pre-generated matrix.

Apparatuses, methods, and systems for precoding multi-carrier signals are disclosed. One method includes obtaining a transmission channel matrix between a terminal and a plurality of separate users, wherein the transmission channel matrix includes channel estimates for a plurality of subcarriers of the multi-carrier signal. A channel dimension reduction matrix is determined based upon a composite of the channel estimates for the plurality of subcarriers, wherein dimensions of the channel dimension reduction matrix are less than dimensions of the transmission channel matrix. The method further includes determining a precoding matrix for the terminal based on the channel dimension reduction matrix, wherein the precoding matrix is multi-carrier signal independent, determining an effective channel based on a channel estimate of the transmission channel and based on the precoding matrix of the terminal, and determining a precoding matrix for the central processing unit based on the effective channel.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). According to various embodiments, in a multiple-input multiple-output wireless communication system, a receiving apparatus may include at least one processor and at least one transceiver. The at least one transceiver may be configured to receive a signal including a plurality of symbols, perform Successive Interference Cancellation (SIC) related to a first symbol of the plurality of symbols on the received signal to obtain a processed signal, determine symbol-sums by applying an equalization matrix for integer forcing to the processed signal, and determine information words corresponding to the plurality of symbols based on the symbol-sums.

The present invention discloses an adaptive parameter adjustment method for a hybrid precoding millimeter-wave transmission system. The method includes the following step: interacting between a transmitter and a receiver for a number of radio frequency chains that need to be established. The receiver calculates, according to a received signal power at the time of established a different number of radio frequency chains and a total power consumption at the time of established the different number of radio frequency chains, the number of the radio frequency chains that need to be established. According to the present invention, under a condition of balancing power consumption and a rate, a number of radio frequency chains that need to be established is adaptively selected, so as to optimally configure power consumption and a transmission rate in a millimeter-wave transmission system.

A system for acquiring channel knowledge and a method thereof are provided. At least one transmitter generates multiple directional beams in different directions, next modulates the directional beams in the different directions with at least one spreading sequence, so as to enlarge the beam range of each directional beam in the different directions and use the modulated directional beams as training-specific beams in the different directions, and sweeps the multiple training-specific beams in the different directions by using a plurality of antennas, so that at least one receiver measures at least one training-specific beam, and determines the channel knowledge according to the measurement result and beam-related information associated with the at least one training-specific beam, so as to achieve a technical effect of reducing training overhead.

Embodiments of the invention provide a decoder for decoding a signal received through a transmission channel in a communication system, said signal comprising a vector of information symbols, wherein the decoder comprises: a processing unit (307) configured to determine at least one candidate set of division parameters and to perform a division of said vector of information symbols into a set of sub-vectors in association with each candidate set of division parameters, each pair of sub-vectors being associated with a division metric; a selection unit (309) configured to select one of said candidate sets of division parameters according to a selection criterion depending on said division metric; and a decoding unit (311) configured to determine at least one estimate of each sub-vector associated with said selected set of division parameters by applying a symbol estimation algorithm,
wherein the decoder is configured to determine at least one estimate of the vector of information symbols from said at least one estimate of each sub-vector of information symbols.