SER Analysis and Power Allocation of OSTBC-OFDM With Channel Estimation Error

Abstract

In this paper we consider a MIMO-OFDM system, with orthogonal space time block code (OSTBC), under the condition of channel estimation error. First we derive a simple closed-form formula for the symbol error rate, assuming a Gaussian channel estimation error. Then, we present an adaptive power allocation, across both the time slots and subcarriers, to minimize the symbol error rate. Our analysis is based on number of transmit and receive antenna, the code rate of OSTBC, number of subcarriers and a parameter determining Gaussian channel estimation error. Simulation results confirm the accuracy of our SER expression and its improvement by our proposed adaptive power allocation method.