Noncoherent detection of BFSK signals with linear and nonlinear diversity combing over Rician fading channels with partial-band interference

Abstract

A performance analysis of Binary Orthogonal Frequency Shift Keying (BFSK) Fast Frequency Hopped (FFH) receivers implemented with both square-jaw and envelope detectors is performed. Bit error possibilities of the two types of receivers for linear combining, noise-normalization combining, and self-normalization combining under worst case partial-band interference with nonselective Rician fading and thermal noise are compared. The analysis is repeated for the case of no interference to point out the effect of fading. A study of nonlinear diversity combining receivers (self-normalization and noise-normalization) is also performed for a system model that is free from thermal noise. Envelope and square-jaw detectors for particular types of nonlinear combining investigated do not differ in performance, but this is not true for linear combing detectors.. The visible superiority of envelope detectors for linear combining is noted. Nonlinear combining receivers achieve a diversity and performance improvement compared to linear combining receivers.