MRCS -- selecting maximal ratio combined signals: a practical hybrid diversity combining scheme

• Published in: IEEE transactions on wireless communications 2009-07, Vol.8 (7), p.3425-3429
• Main Authors: du Pin Calmon, F., Yacoub, M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Base stations; Closed-form solution; Derivation; Diversity combining; Diversity reception; Equipments and installations; Exact sciences and technology; Exact solutions; Fading; Formulations; Mathematical analysis; maximal-ratio combining; Mobile radiocommunication systems; Nakagami distribution; Nakagami-m; Networks; Performance analysis; Probability distribution; pure selection combining; Radiocommunications; Signal processing; Signal to noise ratio; Site selection; soft handoff; Studies; Telecommunications; Telecommunications and information theory; Wireless communication; Wireless networks
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2009.080949

This paper presents and investigates a general diversity combining scheme, here named MRCS, in which maximal-ratio combined signals are chosen on a selection combining basis. This combining method has a simple implementation and a tractable analytical formulation that can be directly applied to situations in which site selection exists. A general analysis of the probability distribution (reliability), level crossing rate, and average fade duration at the output of the combiner is provided, along with examples for a Nakagami-m fading environment. The main result of the present work, however, is the derivation of an exact, easy-to-evaluate closed-form expression for the mean signal-to-noise ratio at the output of the combiner. Such an expression is applicable for conditions in which the product of the number of maximal-ratio combining branches and the Nakagami-m parameter is an integer and it generalizes a result presented elsewhere in the literature. The formulations derived here find a direct applicability in the dimensioning of practical wireless networks.