Signal Design with Low/Zero Ambiguity Zone Characteristics for Joint Radar-Communication Systems

In this paper, a new concept called low/zero ambiguity zone (LAZ and ZAZ) for joint radar-communication signal design is introduced. The signals or code sequences having LAZ/ZAZ characteristics are desirable in modern communication and radar systems operating in high mobility environments especially in high frequency bands. Bounds on periodic LAZ/ZAZ of unimodular Doppler-resilient sequences (DRS) are derived, which include the existing bounds on periodic global ambiguity function as special cases. These bounds may be used as theoretical guidelines to measure the optimality of code sequence design. In addition, two classes of optimal constructions of DRSs with respect to the derived lower bounds on the ambiguity function are also presented.