- T. Yoo and A. Goldsmith,“Sum-rate optimal multi-antenna downlink beamforming strategy based on clique search,” in Proc. IEEE GLOBECOM, Nov. 2005, pp. 1510–1514.
Theorem 1: Assume the i.i.d Rayleigh fading channel model of Section II. Assume that users have equal SNRs, i.e., . Then the probability that the optimal ZFBF user set forms a clique approaches 1 as . That is,