On the Performance of Equalization Techniques for Aeronautical Telemetry

This paper compares the performance of the zero forcing (ZF), minimum mean-squared error (MMSE), and MMSE-initialized CMA+AMA equalizers using SOQPSK-TG over multipath channels captured during channel sounding experiments at Edwards AFB. The ZF and MMSE equalizers are data-aided and are based on estimates of the channel conditions derived from the preamble and ASM bits included in each iNET packet. The simulated bit error rate results show that MMSE and CMA+AMA achieve similar performance and are both about 1 -- 3 dB better than the ZF equalizer. Comparison with the optimum AWGN detector shows that 4 -- 9 dB of link margin is required to account for the multipath interference.