A study on the co- and adjacent channel protection requirements for mobile satellite ACSSB modulation

Results are presented for samples of speech modulated by NBFM (cellular) and ACSSB radios that were subjected to simulated co-channel and adjacent channel interference environments typical of proposed FDMA mobile satellite systems. These samples were then listened to by a group of evaluators whose subjective responses to the samples were used to produce a series of graphs showing the relationship between subjective acceptability, C/No, C/I , and frequency offset. The results show that in a mobile satellite environment, ACSSB deteriorates more slowly than NBFM. The co-channel and adjacent channel protection ratios for both modulation techniques were roughly the same, even though the mechanism for signal deterioration is different