Distributions of Even-Degree-of-Freedom Generalized-Rician Fading for Opportunistic-Relay Selection Employing MRC Under Outdated-CSI Conditions

Distributions of colluding decode-and-forward (DF) opportunistic relays (ORs) employing maximal ratio combining under outdated channel state information (CSI) and independent and identically distributed (i.i.d.) generalized-Rician fading, including line-of-sight (LoS) fading, are fundamentally reported in this paper for the first time. DF-OR collusion can be initiated by employing a broadcast protocol at the destination. The new findings: 1) generalize existing findings under i.i.d. Rayleigh fading employing selection combining and 2) advance theoretical developments for wireless DF-OR networks. Mathematical expressions for: 1) average bit-error-rate of common modulation schemes and 2) ergodic channel capacity inner bounds are given in the compact infinite-summation form, which can be employed to assess the effectiveness of system coherence, a transmit signal-to-noise ratio, the number of DF ORs, degrees of freedom, and LoS power. Because of the LoS component under generalized-Rician fading, infinite summations must be mathematically employed, which are shown to fast converge for a finite number of terms, effectively realizing their practicality. Monte Carlo simulation results are also given under symbols, which match the proposed theoretical predictions.