Apparatus and method for transmit diversity

摘要

Disclosed is a method and apparatus for enhancing diversity gain without reducing data rate by increasing the number of antenna elements and configuring the antenna elements for improving signal-te-noise ratio at a receiver. The antenna array comprise a first antenna group with at least two antenna elements and a second antenna group with at least one antenna element. The first and second antenna groups are spaced approximately ten carrier wavelengths or more apart from each other, and the antenna elements belonging to the first antenna group are spaced approximately a half carrier wavelength or less apart from each other. A plurality of data streams is generated from a signal and used to produce a first and second plurality of representative data streams. Each of the first plurality of representative data streams is phase-shifted and encoded using different orthogonal codes, and each of the second plurality of representative data streams is encoded using different orthogonal codes, wherein a different orthogonal code is used to encode representative data streams in the first and second plurality of representative data streams generated from a same data stream, and the first and second plurality of representative data streams allow for the plurality of data streams to be recovered at a receiver after encoding. The encoded and phase shifted first plurality of representative data streams being transmitted over the first antenna group, and the encoded second plurality of representative data streams being transmitted over the second antenna group.