In a multiuser (MU) multiple antenna system (MAS), a central processing unit is communicatively coupled to multiple distributed wireless terminals (WTs) via a network. The central processing unit processes channel measurements indicative of channel conditions between the multiple distributed WTs and a plurality of user devices and selects a plurality of WTs from the multiple distributed WTs to enhance channel space diversity within the MU-MAS. The central processing unit calculates (Multiple Input, Multiple Output) MIMO weights from the channel measurements for precoding a plurality of data streams that are transmitted concurrently from the plurality of WTs to the plurality of users, wherein the MIMO weights provide for a plurality of independent MIMO channels.

An attenuator is configured to attenuate and phase-shift a radiofrequency signal according to a control signal, having a plurality of first attenuation cells (A.sub.1, A.sub.N−1), configured to attenuate said radiofrequency signal by a predetermined value and activated according to a particular bit of the control signal, and implementing a combinatorial logic on the bits of the control signal that are used to control the first attenuation cells, and at least one second attenuation cell (B.sub.1, B.sub.M) configured to attenuate said radiofrequency signal by a predetermined value and activated according to a particular output implementing the combinatorial logic. A control node is also provided for an array antenna having such an attenuator, and an array antenna having an array of such control node and a satellite.

Embodiments of the present disclosure provide a MIMO communication method and system, and a receiver node. The method includes: receiving, by a number of optical detection modules of a receiver node, optical signals transmitted by a number of optical transmission modules of a transmitter node. Different optical detection modules of the receiver node have different orientations, and different optical transmission modules of the transmitter node have different orientations.

The wireless communications system comprises: a plurality of remote units, wherein each remote unit is configured to convert a respective RF signal into a plurality of time and frequency samples, perform a noise estimation corresponding to the plurality of time and frequency samples, compute a plurality of coefficients corresponding to the plurality of time and frequency samples that have an amplitude greater than at least a predefined threshold value, and multiply each of the plurality of coefficients by its corresponding time and frequency sample to create a plurality of weighted time and frequency samples; at least an intelligent switching unit, coupled to the plurality of remote units, wherein the intelligent switching unit is configured to receive the plurality of weighted time and frequency samples from each of the plurality of remote units, temporally align the pluralities of weighted time and frequency samples, compute a set of weighted sums of time and frequency samples and transmit the set of weighted sums of time and frequency samples; and a baseband processing unit coupled to the intelligent switching unit and configured to receive the set of weighted sums of time and frequency samples, and compute a remaining portion of baseband protocol stack processing on the set of weighted sums of time and frequency samples.

An N-element baseband (BB) time-domain spatial signal processor system and methodology for large modulated bandwidth multi-antenna receivers are provided. Such a processor generally includes a pipeline converter configured as an asynchronous time-to-digital converter, wherein the asynchronous time-to-digital converter arrangement generates a residue value and an asynchronous pulse and is further arranged to amplify the residue value so as to result in an amplified residue value; and a 2-bit flash time-to-digital-converter configured to quantize the amplified residue value. Thus, a true-time delay spatial signal processing system and technique in the time-domain that enables beamforming, beam-nulling and multiple independent interference cancellation after time-alignment of signals using cascaded voltage-to-time converters and quantization using relaxed pipeline time-to-digital converters is presented.

The wireless communications system comprises: a plurality of remote units, wherein each remote unit is configured to convert a respective RF signal into a plurality of time and frequency samples, perform a noise estimation corresponding to the plurality of time and frequency samples, compute a plurality of coefficients corresponding to the plurality of time and frequency samples that have an amplitude greater than at least a predefined threshold value, and multiply each of the plurality of coefficients by its corresponding time and frequency sample to create a plurality of weighted time and frequency samples; at least an intelligent switching unit, coupled to the plurality of remote units, wherein the intelligent switching unit is configured to receive the plurality of weighted time and frequency samples from each of the plurality of remote units, temporally align the pluralities of weighted time and frequency samples, compute a set of weighted sums of time and frequency samples and transmit the set of weighted sums of time and frequency samples; and a baseband processing unit coupled to the intelligent switching unit and configured to receive the set of weighted sums of time and frequency samples, and compute a remaining portion of baseband protocol stack processing on the set of weighted sums of time and frequency samples.

An antenna array decoupling method, apparatus and system, and a non-transitory computer-readable storage medium are disclosed. The method may include: receiving predetermined digital domain signals of a plurality of channels, each of the plurality of channels being a data channel corresponding to a respective one of array elements in an antenna array (S110); determining decoupling factors of channels involved in decoupling corresponding to each channel, the decoupling factors being factors which have been solved for beforehand according to measured in-array pattern information of each array element in the antenna array (S120); and processing the predetermined digital domain signals of the channels involved in decoupling corresponding to each channel according to the decoupling factors to obtain a decoupled predetermined digital domain signal of each channel (S130).

In one implementation, a wireless communications terminal includes a multi-element antenna. In addition, the terminal includes preliminary signal combiners to combine received signals output by corresponding pairs of antenna elements. For each preliminary signal combiner, the signal output by a first of the pair of elements provides a model of interference present in the received signal output by the second of the pair of elements. The preliminary signal combiner is configured to combine the signal output by the first element with the signal output by the second element to produce an initial interference-mitigated signal. The terminal also includes phase shifters to apply complex weights to interference-mitigated signals to produce complex-weighted versions of the interference-mitigated signals and effectively steer a main beam of the antenna to facilitate reception of a desired signal and another signal combiner to combine the complex-weighted versions of the interference-mitigated signals to produce an interference-mitigated output signal.

An antenna system includes a module that is electrically coupled to a front-end electronic circuit layer configured to process one or more beams. The module includes a radiation layer including one or more radiating elements configured to at least one of transmit and receive the one or more beams and a feed layer including one or more feed elements, where the one or more feed elements are configured to excite the radiation layer, transmit the one or more beams, receive the one or more beams, or a combination thereof. The module further includes a distribution network layer including a wave distribution device, where the wave distribution device is configured to distribute the one or more beams from the front-end circuit layer to the feed layer.

A method is provided for using an antenna array to create two beams (a first beam and a second beam). In one aspect, the method uses dual polarization beam forming, which allows for many degrees of freedom in designing a desired power pattern. The method is well suited for systems with multiple radio chains (e.g., systems with active antennas). The method is also well suited for multi-port systems such as TD-SCDMA. In some embodiments, the method produces two beams where (a) the shape of the power beam pattern for the first beam and the shape of the power beam pattern for the second beam are the same (or substantially the same) in a plurality of directions of interest and (b) the beams have orthogonal (or substantially orthogonal) polarizations in the coverage area.