Diversity ECCM Performance of Frequency-Hopping CPFSK in Partial-Band Noise Jamming

摘要

A thorough analysis is made of the uncoded probability of error achieved by by a hopped CPFSK (narrowband digital FM) radio link while subject to partial band noise jamming. Included in the analysis are the effects of thermal noise, FM clicks, and intersymbol interference, in addition to the jamming. For both limiter-discriminator and differential detection, it is shown that a repeat diversity combining method of summing detector samples does not yield a diversity gain against worst-case partial-band noise jamming, despite the nonlinearity of the receiver. The analytical procedures formulated, and computer programs developed, can be modified to treat other CPFSK combining metrics; it is recommended that other soft-decision metrics be evaluated for ECCM properties, since it is known that at diversity gain is theoretically possible using perfect side information. In the report, easily calculated approximations and short-cut expressions for the error probability are assessed for accuracy, using the more complicated exact formulas. Keywords: Frequency shift keyers; Continuous phase, Frequency hopping, Digital FM radio, ECCM, jamming, Statistical communication theory; Phase distributions. (JD/RH)