Mimo systems with active scatters and their performance evaluation

Abstract

A communications system includes at least one receiver having receiving elements and a transmitter having transmitting elements to transmit signals to the receiving elements via wireless propagation channels. The transmitter includes a beam-forming network and a channel measurement unit. The beam-forming network receives input signal streams at its input ports and outputs one or more signals as shaped beams based on a set of composited transfer functions. The channel measurement unit performs measurements of components of channel status information to generate a set of point-to-point transfer functions and generates the composited transfer functions by computing linear combinations of the point-to-point transfer functions. Each of the point-to-point transfer functions characterizes propagation paths from one of the transmitting elements to one of the receiving elements. The composited transfer functions are point-to-multipoint transfer functions characterizing propagation paths from the input ports of the beam-forming network to one or more of the receiving elements.