A modified algorithm of Ricean Factor K estimation for L-DACS1 system

One deployment option for future civil air-ground broadband communication named L-band Digital Aeronautical Communications System 1 is proposed by International Civil Aviation Organization and earlier drafted by German Aerospace Research Center. Besides the serious time selective fading for channel, interference originating from Distance Measure Equipment (DME) operating in adjacent channels in L-band has a strong impact on t Ricean factor K estimation. This paper proposed a modified algorithm of Ricean Factor K estimation based on OFDM pilot and virtual sub-carrier, which mitigate the impact of interference of DME to Ricean Factor K estimation, and the algorithm improve the estimation precision of Ricean Factor K in the case of low signal-to-noise ratio (SNR). The results of simulation show that performance of the algorithm is much superior to the moment-based estimation algorithm on the condition that SNR is 3dB-5dB.