Advanced Signal Processing Algorithms for Energy-Efficient Wireless Communications

Substantial progress has been made in the receiver signal processing algorithms for wireless communications to minimize the requirements on signal to noise (and/or interference) power ratio and computational complexities for the same quality of service. In cellular infrastructure systems, one of the key system design objectives in the base stations is to maximize the receiver sensitivity, so that the required signal level from the mobile stations could be minimized. The use of advanced signal processing algorithms based on maximum a posteriori (MAP) estimation, iterative (turbo) channel estimation, equalization, and decoding allows for a reduction of the required transmitter power by 1/3 to 1/2. Lower computational complexities in the terminals, which implies a reduced power drain on the digital circuits, can be achieved by the use of techniques that adapt the state complexity of the receiver to the propagation channel. We give an in-dept review of these algorithms, and discuss their performance and implementation requirements.