First user equipment (UE) exchanges at least a portion of data to be transmitted to a communication network with a second UE on a side channel. The UEs then send the data to the network at increased transmission power by using transmit antennas of both the first and second UEs, instead of just those of the first UE. In some cases, the second UE may transmit a variation of the data sent by the first UE to perform transmit diversity and improve signal-to-noise ratio. To avoid unintended beamforming of the transmissions, the network may mix signals (e.g., having a same symbol) received at the same time period but at different sub-carriers, or mix the signals received at different time periods but at the same sub-carrier. The network may notify the UEs of a phase correction value based on the signals, and the UEs may adjust using the phase correction value.

Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal over the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a baseband signal after a first mapping and a baseband signal after a second mapping by a precoding weight and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

The object of the present invention can be achieved by providing a method of transmitting broadcast signals including encoding Data Pipe, DP, data, wherein the encoding further includes Forward Error Correction, FEC, encoding the DP data, Bit interleaving the FEC encoded DP data and mapping the bit interleaved DP data onto constellations; building at least one signal frame by mapping the encoded DP data; and modulating data in the at least one built signal frame by an Orthogonal Frequency Division Multiplexing, OFDM, method and transmitting the broadcast signals having the modulated data, wherein each of the at least one signal frame includes at least one preamble having repeated at least one signaling information.

A wireless communication device serving as an NG60 WiGig device includes a PPDU generator that generates an MF control PHY PPDU (physical layer protocol data unit) including a legacy preamble, a legacy header, an NG60 header (a non-legacy header), a data field, and identification information indicating that the non-legacy header is included in the PPDU and a transmitter that transmits the generated MF control PHY PPDU.

A method of operating a network node of a communication network includes receiving, by a first decoder of the network node, a first upstream-processed signal associated with an original signal. The method further includes receiving, by a second decoder of the network node, a second upstream-processed signal associated with the original signal. The method further includes determining, by the first decoder, a first downstream-processed signal based on the first upstream-processed signal and outputting, by the first decoder, the first downstream-processed signal. The method further includes responsive to the first decoder outputting the first downstream-processed signal, determining, by the second decoder, a second downstream-processed signal based on the second upstream-processed signal and the first downstream-processed signal and outputting, by the second decoder, the second downstream-processed signal. The method further includes determining a decoded received signal based on outputs from the first decoder and the second decoder.

Methods, systems, and devices for wireless communications are described. A base station may associate a first and second port with a set of antenna elements based on a first and second linear precoding vector. The base station may generate coefficients indicating a first combination and a second combination of a first data set for a first user equipment (UE) and a second data set for a second UE. The base station may apply the first and second linear precoding vectors to the first and second combinations, respectively, transmit a first demodulation reference signal (DMRS) and a second DMRS using a first comb corresponding to the first and second ports, and transmit at least a third DMRS indicating the coefficients using a second comb. The UEs may extract data from the precoded combinations by applying the coefficients and estimating channels associated with the first and second DMRS.

A method of reception of signals transmitted by a FBMC transmitter using a block Alamouti coding. After demodulation in a base band, the received signal is sampled, with the sample blocks undergoing a sliding FFT before being de-multiplexed towards a first path during a first use of the channel and a second path during a second use of the channel. The vectors received on the first path are multiplied by a first and a second transfer matrix, conjugated to provide first and second vectors. The vectors received on a second path undergo time-reversal and complex conjugation and, if appropriate, multiplication by an imaginary factor, depending on the size of the blocks. The vectors thus obtained are multiplied by first and second transfer matrices to provide third and fourth vectors. The first and fourth (second and third vectors) are then combined and the combined vector is filtered and spectrally de-spread to give an estimate of the block transmitted by the first (second) antenna of the transmitter during the first use of the channel.

A method and apparatus for implementing spatial processing with unequal modulation and coding schemes (MCSs) or stream-dependent MCSs are disclosed. Input data may be parsed into a plurality of data streams, and spatial processing is performed on the data streams to generate a plurality of spatial streams. An MCS for each data stream is selected independently. The spatial streams are transmitted via multiple transmit antennas. At least one of the techniques of space time block coding (STBC), space frequency block coding (SFBC), quasi-orthogonal Alamouti coding, time reversed space time block coding, linear spatial processing and cyclic delay diversity (CDD) may be performed on the data/spatial streams. An antennal mapping matrix may then be applied to the spatial streams. The spatial streams are transmitted via multiple transmit antennas. The MCS for each data stream may be determined based on a signal-to-noise ratio of each spatial stream associated with the data stream.

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, said transmission channel being represented by a channel matrix comprising column vectors, said information symbols carrying information bits, wherein the decoder comprises: a transformation unit (401) configured to determine a set of auxiliary channel matrices, each auxiliary channel matrix being determined by performing a linear combination of at least one of the column vectors of said channel matrix; a decomposition unit (407) configured to determine a decomposition of each auxiliary channel matrix into an upper triangular matrix and an orthogonal matrix; a matrix selection unit (409) configured to select at least one auxiliary channel matrix among said set of auxiliary channel matrices depending on a selection criterion related to the components of said upper triangular matrices.

The decoder being configured to determine an auxiliary signal by multiplying the transpose of the orthogonal matrix corresponding to said selected auxiliary channel matrix by said received signal, the decoder being configured to determine at least one estimate of said vector of information symbols from said auxiliary signal and from the upper triangular matrix corresponding to said selected auxiliary channel matrix by applying a decoding algorithm.

An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.