Method and apparatus for antenna selection in a mimo system

Abstract

Transmission schemes that can flexibly achieve the desired spatial multiplexing order, spatial diversity order, and channel estimation overhead order are described. For data transmission, the assigned subcarriers and spatial multiplexing order (M) for a receiver are determined, where M = 1. For each assigned subcarrier, M virtual antennas are selected from among V virtual antennas formed with V columns of an orthonormal matrix, where V = M. V may be selected to achieve the desired spatial diversity order and channel estimation overhead order. Output symbols are mapped to the M virtual antennas selected for each assigned subcarrier by applying the orthonormal matrix. Pilot symbols are also mapped to the V virtual antennas. The mapped symbols are provided for transmission from T transmit antennas, where T = V. Transmission symbols are generated for the mapped symbols, e.g., based on OFDM or SC-FDMA. Different cyclic delays may be applied for the T transmit antennas to improve diversity.

Description

Method and apparatus for antenna selection in a multiple-input multiple-output system Related Application Cross Reference This application claims priority over U.S. Provisional Patent Application No. 60 / 710,408 and U.S. Provisional Patent Application No. 60 entitled "Method and Apparatus for Antenna Diversity in Multi-input Multi-Output Communication Systems" filed on August 24, 2005 / 711,144, both assigned to the assignee of the present invention and incorporated herein by reference. This application is further related to commonly assigned US patent application entitled "Adaptive Sectorization in Cellular Systems," pending on the same date herewith, and incorporated herein by reference. technical field The present disclosure relates generally to communications, and more particularly to transmission schemes for wireless communications. Background technique In a wireless communication system, a transmitter (eg, a base station or a terminal) may utilize multiple (T) tra...

AI Technical Summary

Problems solved by technology

The main disadvantage of using multiple transmit antennas for data transmission is that it is usually necessary to estimate the channel response between each pair of transmit and receive antennas (or each propagation path) in order to correctly receive the data transmission

First, in order to transmit pilots for channel estimation, a large amount of link resources may be consumed, which in turn reduces the link resources available for transmitting data

Second, channel estimation for all T-R transmit and receive antenna pairs increases processing overhead at the receiver

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