Detection of Frequency-Hop Signals

This paper examines the performance and trade-offs associated with detecting frequency-hop signals by means of multiple observations in the presence of narrowband interfering signals. An adaptive algorithm is proposed for utilizing the outputs from a parallel filter bank observed over a number of time intervals to make decisions on the presence of one or more frequency-hop signals. Trade-offs among the number of filters, the number of time intervals, the time-bandwidth product of each energy detector, and the total observation time are explored by means of computer simulation. The probability of detection for a specified probability of false alarm is determined as a function of the frequency-hop signal power for various numbers of interfering signals. The degradation in performance that results from not observing the frequency-hop signal synchronously with the hops is evaluated, as is the effect of not knowing the hop rate.