Abstract

One of several proposed multicarrier demultiplexer/demodulator (MCDD) structures is studied for application to satellite on-board regenerative repeats. The structure considered here is the multistage multicarrier demultiplexer/demodulator (M-MCDD). The M-MCDD has been chosen as the preferred structure for demultiplexing signals composed of N = 2 1 channels due to its high level of modularity, low computational complexity and low power consumption. Originally proposed by Göckler in 1992, the M-MCDD is considered one of the best available MCVDs to demultiplex composite MF-TDMA signals in the presence of additive white Gaussian now (AWGN) and adjacent channel interference (ACI). Adjacent channel interferrence (ACI) is the result of imperfect filtering, which can be induced by any filtering method, and insufficient channel separation within the aggregate input signal. An AWGN analysis is carried out considering the presence of ACI within the M-MCDD. Once the effect of ACI an the performance of the M-MCDD is determined the AWGN analysis will be extended by assuming that the halfband filter coefficients are quantized in value as opposed to being real-valued. This will also introduce quantization noise into the demultiplexed output. Due to the complexity induced by ACI and the combination of ACI with quantization noise, we rely on analytical techniques to arrive at approximate numerical solutions, with calculable error margins, for the performance of the M-MCDD. One of the important applications of the numerical solutions will be to determine the filter design for the M-MCDD.