Optimal channel switching in the presence of stochastic signaling

Abstract

Abstract-Optimal channel switching and detector design is studied for M -ary communication systems in the presence of stochastic signaling, which facilitates randomization of signal values transmitted for each information symbol. Considering the presence of multiple additive noise channels (which can have nonGaussian distributions in general) between a transmitter and a receiver, the joint optimization of the channel switching (timesharing) strategy, stochastic signals, and detectors is performed in order to achieve the minimum average probability of error. It is proved that the optimal solution to this problem corresponds to either (i) switching between at most two channels with deterministic signaling over each channel, or (ii) time-sharing between at most two different signals over a single channel (i.e., stochastic signaling over a single channel). For both cases, the optimal solutions are shown to employ corresponding maximum a posteriori probability (MAP) detectors at the receiver. Numerical results are presented to investigate the proposed approach.

Optimal channel switching for average capacity maximization

“…In practice, this assumption can be realized by employing a communication protocol that allocates the first N s,1 symbols in the payload for channel 1, the next N s,2 symbols in the payload for channel 2, and so on. The information on the number of symbols for different channels can be included in the header of a communications packet [10,19].…”

“…In the presence of multiple channels between a transmitter and a receiver, it may be advantageous to perform channel switching; that is, to transmit over one channel for a certain fraction of time, and then switch to another channel during the next transmission period even if the channel statistics are not varying with time [6,17,18,19]. In [6], it is shown that the optimum performance under an average power constraint can be achieved by time sharing between no more than two channels and power levels.…”

“…In [6], it is shown that the optimum performance under an average power constraint can be achieved by time sharing between no more than two channels and power levels. In addition, [19] considers the channel switching problem in the presence of stochastic signaling, and obtains the optimal strategy, which can involve either transmitting over a single channel with deterministic or stochastic signaling, or channel switching between two channels with deterministic signaling.…”

“…Although the optimal channel switching problem is studied in [6] and [19] in terms of average probability of error minimization, no studies in the literature have considered the channel switching problem for capacity maximization. In this study, we formulate the optimal channel switching problem for capacity maximization under average and peak power constraints, and derive a necessary and sufficient condition for the proposed channel switching approach to achieve a higher average capacity than the no channel switching approach.…”

Optimal signaling and detector design for M-ary communication systems in the presence of multiple additive noise channels

“…In a recent conference paper [28], we have presented the optimal channel switching, signaling and detection problem, and provided its solution. The current paper presents a more detailed derivation of this solution.…”