摘要 : An f.s.k. signal keyed at 75 bauds with 850 Hz frequency shift, can have one of several frequency allocations within any given h.f. voice channel. In the presence of interference from other users, the f.s.k. system performance may... 展开 An f.s.k. signal keyed at 75 bauds with 850 Hz frequency shift, can have one of several frequency allocations within any given h.f. voice channel. In the presence of interference from other users, the f.s.k. system performance may be improved by choosing the f.s.k. tone frequencies before message transmission, to correspond to frequencies within the voice channel where the interference is least. This paper reports on an 800 km point-to-point h.f. link experiment which investigated this principle, combined with forward error-correcting codes, with the aim of improving aeromobile data transmission. 收起