Analysis of the Normalized LMS Optimum Solution in the Context of Channel Equalization

Albeit being presented as an alternative to the classical least-mean-square (LMS) algorithm, the normalized LMS (NLMS) actually deals with a modified mean squared error (MSE) cost function, so that the expected optimum solution may differ from the Wiener solution. In this work, we perform an investigation concerning the question as to whether such difference may arise in the context of the channel equalization problem by considering a representative set of transmitted signal modulations, channel models and signal-to-noise ratio (SNR) conditions. Additionally, we analyze the influence of the potential deviation from the optimal solution on the performance of the equalizer.