Maximum Likelihood bounds for linear precoded OFDM systems

Classes of channel independent linear precoded OFDM systems are finding application in modern wireless communication protocols such as LTE. There is a need to provide accurate and simple Maximum Likelihood (ML) error rate bounds for the evaluation of these systems. In this paper we extend our previous work in this area by providing some limiting cases which become simple closed expressions facilitating ease of use. We also argue that these closed expressions are sufficiently accurate for modest system sizes and show that they provide an insight into the operation of linear precoding. To complement and strengthen our previous work we also present some additional simulation results illustrating the tightness of the ML bounds when using 16-QAM.