EXPERIMENTAL RESULTS FOR PCM/FM, TIER 1 SOQPSK, AND TIER II MULTI-H CPM WITH CMA EQUALIZATION

Abstract

It is widely recognized that telemetry channels, particularly airborne channels, are afflicted by multipath propagation effects. It has also been shown that adaptive equalization can be highly effective in mitigating these effects. However, numerous other factors influence the behavior of adaptive equalization, and the type of modulation employed is certainly one of these factors. This is particularly true on modulations that exhibit different operating bandwidths. Computer simulations using the Constant Modulus Algorithm (CMA) have recently been reported for PCM/FM, ARTM Tier 1 SOQPSK, and Tier II SOQPSK. These encouraging results have led to a hardware implementation of a CMA equalizer. This paper presents the latest results from this work.