Groupwise generalized selection diversity combining and its applications in wireless communication

The paper introduces a new concept of groupwise generalized selection combining (GGSC), denoted by GGSC(n, m, L) , in which there are n groups of generalized selection combining GSC(m, L) where the largest m (in SNR) elements are selected from L independent elements. The paper proves that GGSC(n, m, L) has the same diversity order (DO) as that of MRC with nL elements, denoted by MRC(nL) and GSC(nm, nL) which selects the same number of branches globally from the same total of nL elements. The paper quantifies the performance differences among GGSC(n, m, L) , GSC(nm, nL) and MRC(nL). The paper shows the SNR loss of GGSC(n, m, L) relative to GSC(nm, nL) is less than 2.59 dB for arbitrary m, n and L. For diversity orders of practical interest (<12), the loss is less than 0.6 dB.