Achievable Rate of a Noncoherent SIMO System With Multi-Level ASKs Under Rician Fading Environment

This paper analyzes the achievable rate of a single-input multiple-output wireless communication system with the channels subjected to Rician fading. The transmitter is considered to employ either a one-sided or two-sided amplitude shift-keying (ASK) modulation scheme for data transmission. The transmitted data symbols are detected using a noncoherent receiver, which utilizes the statistical knowledge of the channel states. Using the statistics of the received signal vector, an upper bound on the mutual information is obtained. A framework is provided to obtain the input probabilities that maximize the upper bound on the mutual information. From the numerical results, it is observed that at low signal-to-noise ratio values, the input probabilities are not uniform. Furthermore, using two-sided ASK modulation results in a higher achievable rate than using one-sided ASK modulation.