Characteristics of a simulated fast fading indoor radio channel

The channel characteristics of an indoor radio channel vary very slowly. A simple technique that introduces a fast fading effect on the channel is presented. This scheme requires two or more antennas at the transmitter and has to be used with a suitable channel code. Slow time varying phase offsets are provided to each transmit antenna. Because of the resulting fast fading effect, with this scheme, time diversity can be employed usefully in a coded system. The indoor radio channel is represented by a slow fading Rayleigh channel model, and analytical expressions are provided for the correlation of the received signal in the presence of this simulated fast fading scheme. Expressions are derived for the level crossing rate and the average fade duration of the envelope of the received signal.