The WESt combiner: benefits in digital radio systems for space diversity receivers

The paper presents an efficient combination strategy for Space Diversity Receivers. The improved system performance obtained in High Capacity SDH Digital Radio with QAM modulation formats are shown. The combination control algorithm optimises the system performance using a strategy that properly weights power level and spectrum distortion to evaluate their impact on BER, and consequently acts on a RF endless phase shifter and two paths IF relative amplitude to optimise BER itself. First application of WESt (Weighted Evaluation Strategy) combiner was for a 6L band, 128 TCM (Trellis Coded Modulation) lxSTM-1 signal: laboratory test set and measurements are presented.