Application of Receive Diversity to Rapidly Time Varying Channels with Partial Knowledge at the Receiver

Abstract

For coherent detection accurate channel knowledge is required at the receiver. But in rapidly time varying channels this leads to poor spectral efficiency. A possible compromise is to use partial channel knowledge at the receiver. However as can be seen from [4], partial channel knowledge degrades the BER performance over rapidly time varying channels in Single Input Single Output (SISO) systems. In this paper we consider multiple antennas at the receiver with Maximal Ratio Combining (MRC) and Equal Gain Combining (EGC) over rapidly time varying channels with partial knowledge at the receiver. We derive expressions for BER and match them with simulations, and show that it is possible to significantly enhance the BER performance along with simultaneous reduction in channel estimation rate.