Post-Processing Noise of ZF Detector with Varying Channel Condition

Spatial multiplexing increases the efficiency of a multiple input multiple output (MIMO) system by effectively using the available spectrum without the need of an additional power. Among the linear detector, ZF (zero forcing) is the most simple and effective, that regains multiple transmitted data at the receiver. Usually, in a service area, user may experience different channel type from highly scattered environment to less scattered one and hence the post processing noise will vary. Here, we present the mathematical derivation of post-processing SINR and hence the post-processing noise of ZF receiver with imperfect channel estimates for a seven cluster cellular network. We investigate the noise variation with channel condition at the output of MIMO ZF receiver when the channel varies from Rayleigh to Nakagami-m fading for different `m' values in the cellular service area. We find that post processing noise with Rayleigh channel is higher than with Nakagami-m as expected at the ZF receiver output for MIMO system.