A multiple antenna system (MAS) with multiuser (MU) transmissions (MU-MAS) exploiting inter-cell multiplexing gain via spatial processing to increase capacity in wireless communications networks.

A network unit includes a non-linear precoder for jointly pre-processing transmit samples to be transmitted over respective communication channels for crosstalk mitigation. The non-linear precoder includes a first non-linear precoding stage configured to operate according to a first triangular precoding matrix and including a modulo function, followed by a second linear precoding stage configured to operate according to a second precoding matrix. The network unit further includes a first pilot signal generator configured to generate first pilot signals for pre-processing by the second precoding stage only to yield partially-precoded pilot signals for further transmission over the respective communication channels, and a controller configured to update the second precoding matrix based on first error measurements performed during the transmission of the partially-precoded pilot signals over the respective communication channels while keeping the first precoding matrix unaltered.

A base station having an input module for receiving a probe signal sent from a terminal device, and a data processor for generating a signature waveform that is based on channel information derived from the probe signal, identifying data symbols intended to be transmitted to the terminal device, and modifying the data symbols based on the channel information. The modification of the data symbols is designed to reduce inter-symbol interference when the data symbols are received by the terminal device. The data processor generates a downlink signal based on the modified data symbols and the signature waveform. The base station generates a wide-band a radio frequency signal based on the downlink signal and transmits the radio frequency signal to the terminal device through a multipath channel such that a portion of the radio frequency signal intended for the terminal device focuses at the terminal device.

In one example embodiment, a method for reducing an effect of an interference signal on data being transmitted over a communication channel includes determining, by a processor, a code word based on at least an information vector and an interference vector, the information vector representing the data, the interference vector representing the interference signal. The method further includes determining, by the processor, a code vector based on the determined code word. The method further includes generating, by the processor, a transmit vector based on the code vector and the interference vector.

Embodiments of the present disclosure provide a precoding method, a base station and a user equipment. The precoding method comprises: a base station acquires predetermined parameter(s) of at least one user equipment; calculates the acquired predetermined parameter(s) to obtain a calculation performance index; selects a target precoding solution according to the calculation performance index; precodes data information of all the user equipment(s) according to the target precoding solution; if the target precoding solution is a nonlinear precoding solution, sends the data information and indication signaling indicating information of the nonlinear precoding solution to each user equipment; and the user equipment receives the data information and the indication signaling which are sent by the base station; selects a receiver according to a receiver type obtained according to the indication signaling; and detects the received data information using the selected receiver.

A network unit includes a non-linear precoder for jointly pre-processing transmit samples to be transmitted over respective communication channels for crosstalk mitigation. The non-linear precoder includes a first non-linear precoding stage configured to operate according to a first triangular precoding matrix and including a modulo function, followed by a second linear precoding stage configured to operate according to a second precoding matrix. The network unit further includes a first pilot signal generator configured to generate first pilot signals for pre-processing by the second precoding stage only to yield partially-precoded pilot signals for further transmission over the respective communication channels, and a controller configured to update the second precoding matrix based on first error measurements performed during the transmission of the partially-precoded pilot signals over the respective communication channels while keeping the first precoding matrix unaltered.

Sampling circuitry for receiving an analog signal from photodetector circuitry and generating a sample analog signal. Equalization circuitry for generating an equalized signal comprising first and second sample values corresponding with a cursor tap and a first postcursor tap, and one or more third sample values corresponding with taps other than the cursor tap and the first postcursor tap. In the equalized signal, amplitudes of the first and second sample values are substantially equal while the third sample values are attenuated relative to the first and second sample values. The first and second sample values correspond with two or more first symbols of a first alphabet. Data slicer and modulo circuitry to generate a data signal based on the equalized signal and perform a modulo operation on the two or more first symbols and to generate one or more second symbols. The second symbols are according to a second alphabet.