Method and apparatus for reducing antenna correlation

摘要

The present invention is related to a method and apparatus for reducing antenna correlation between multiple antennas. A transmitter generates at least two beams with a plurality of antennas. The generated beams are spatially separated to point away from each other. Therefore, the transmitted signals travel through different channel conditions and arrive at a receiver mutually uncorrelated. The beams may be generated by antennas having different antenna patterns, or by an array antenna. The beams may be polarized differently. The schemes may be implemented on a subcarrier basis in an orthogonal frequency division multiplexing (OFDM) system. Trellis coded mapping may be utilized for adjacent symbols to be mapped to antennas with low correlation.