Good performance i.f. and premodulation filters for simple f.s.k. system

Results are given of a realisable i.f. filter that appears to give the best compromise design for the major performance parameters of an f.s.k. system: signal/noise ratio, intersymbol interference and tolerances to frequency and timing offsets. These results are determined by a computer f.m.-simulator program, keeping all the components ideal except the filters. In addition, various premodulation filters have been investigated, in conjunction with the i.f. filter, in terms of system performance.