Waveform-level precoding with simple energy detector receiver for wideband communication

Wideband waveform-level precoding with simple energy detector receiver is investigated in this paper. The motivation is to provide a cheap radio network with simple receivers and sophisticated transmitters. The energy detector receiver performs relatively poorly, but waveform-level precoding can be used to compensate for the performance loss. Waveform-level precoding is a transmitter-side processing taking advantage of known channel information. Given channel impulse response (CIR), transmitted waveform can be optimized in some criterion. In this paper the optimization goal is to maximize an equivalent signal-to-noise ratio (SNR) at the receiver, assuming no inter-symbol-interference (ISI). Close-form expressions are derived based on the Park´s empirical model for evaluating the receiver operating characteristic (ROC) of energy-detector. Numerical approach is adopted to handle continuous time signals. Channel data measured in office area is used to obtain numerical results. Performance comparison with time reversal precoding as benchmark shows that the optimal waveform can offer gains of several decibels.