Title :
A unified approach to performance evaluation of switched diversity in independent and correlated fading channels
Author :
Annamalai, A. ; Tellambura, C. ; Bhargava, V.K.
Author_Institution :
Dept. of Electr. & Comput. Eng., Victoria Univ., BC, Canada
Abstract :
This paper outlines a unified approach to performance evaluation of a broad class of coherent, differentially coherent and noncoherent digital communication systems, with dual-branch switched diversity (SWC) reception over generalized fading channels. The moment generating function (MGF) of the signal power at the output of the SWC combiner and the first-order derivative of the MGF with respect to the switching threshold are derived. These expressions are obtained for the general case of correlated fading and nonidentical diversity branches, and hold for any common fading distributions (e.g., Rayleigh, Nakagami-m, Rician, Nakagami-q). The optimum switching threshold (in a minimum error rate sense) is obtained by solving a nonlinear equation which is formed by using the first-order derivative of the MGF. This nonlinear equation can be simplified for several special cases: (a) closed-form expressions for the optimal switching threshold are derived for three generic forms of the conditional error probability by assuming independent and identically distributed diversity branches; and (b) a closed-form formula for the optimal switching threshold is derived for the non-coherent binary modulation formats in correlated Rayleigh or Nakagami-m fading with identical fading statistics
Keywords :
Rayleigh channels; correlation methods; digital radio; diversity reception; error statistics; nonlinear equations; Nakagami-m distribution; Nakagami-m fading; Nakagami-q distribution; Rayleigh distribution; Rician distribution; SWC combiner; closed-form expressions; coherent digital communication system; conditional error probability; correlated Rayleigh fading; correlated fading channels; differentially coherent digital communication system; dual-branch switched diversity reception; fading distributions; fading statistics; generalized fading channels; i.i.d diversity branches; independent fading channels; minimum error rate; moment generating function; noncoherent binary modulation formats; noncoherent digital communication system; nonlinear equation solution; optimal switching threshold; optimum switching threshold; output signal power; performance evaluation; switching threshold; unified approach; Communication switching; Digital communication; Diversity methods; Error analysis; Fading; Nakagami distribution; Nonlinear equations; Power generation; Rayleigh channels; Signal generators;
Conference_Titel :
Wireless Communications and Networking Conference, 1999. WCNC. 1999 IEEE
Conference_Location :
New Orleans, LA
Print_ISBN :
0-7803-5668-3
DOI :
10.1109/WCNC.1999.796794
