Post detection weighted vector combining diversity receivers using phase metrics for mobile and indoor radio channels

摘要

A digital radio communications system employs a digital information source for providing digital information such as message bits, a transmitter for transmitting encoded digital information into data symbols in a radio-frequency (RF) signal to a plurality of antennae which sense the transmitted RF signal. A post detection measure of signal quality, the signal-to-impairment ratio, (SIR), is utilized by the receiver to perform post detection combining of signals received by a plurality of antennae. The antennae are coupled to a receiver which for each received signal: digitizes the signal, determines phase angles of the digitized signal, converts the signal to unit vectors, determines a signal-to-impairment ratio (SIR) estimates &ggr;.sup.j of the digitized signals. The SIR estimate &ggr;.sup.j is weighted by combining weight computation element and multiplied by each unit vector to provide an in- phase is component and a quadrature component for each signal. The in- phase components are combined into a in-phase composite signal I.sub.c (n) . The quadrature-phase components are combined into a quadrature-phase composite signal Q.sub.c (n). The composite signal (I.sub.c (n), Q.sub.c (n) is then decoded into phase angles which are reversed mapped to message bits which are utilized by an output device resulting in a radio communication system exhibiting improved performance during radio "fade" periods.