Signal-to-noise ratio and signal-to-impairment ratio estimation in AWGN and wireless channels.

摘要

As the need to support larger numbers of subscribers with higher-quality, wireless services increases, wireless technology must improve to keep up with the demand. Performance-enhancing techniques which historically have been too costly to implement are now gaining favour as digital hardware is becoming ever cheaper and more powerful. Signal-to-noise ratio (SNR) estimation and signal-to-impairment ratio (SIR) estimation algorithms are examples of techniques that may be used to improve receiver functions such as diversity combining and synchronization. Historically, the total signal-plus-noise power or the total signal-plus-impairment power often has been used in favour of the SNR or the SIR since estimators of the total power are easier to implement. Today, inexpensive, powerful digital hardware makes the implementation of SNR or SIR estimators practical so that the performance improvement effected by their use may be realized. In this thesis, various applications that may benefit from use of SNR or SIR estimation are identified.; SNR estimation is studied in the context of BPSK signaling in the real AWGN channel, and 8-PSK signaling in the complex AWGN channel.; SIR estimation in wireless channels is studied by the statistical analysis of SIR estimates generated by the computer simulation of {dollar}pi{dollar}/4-DQPSK-modulated signals in five "typical" mobile radio channels. (Abstract shortened by UMI.)