| 摘要 |
A multiple-hypothesis, multipath-matched filter (10) is disclosed for use in combining multipath components of transmissions between, for example, an aircraft (12) and aircraft (14) through a multipath environment (16). Rather than sensing the characteristics of the environment and adjusting the multipath components accordingly, the disclosed filter is designed on the basis of several hypotheses concerning the differences in the path lengths traversed by the various multipath components, as well as the phase shift introduced into each. In a preferred arrangement, the path length differences DELTA R are assumed to be some integer multiple of the range gate setting delta R of a transmitter/receiver (28) included on the aircraft. The phase shifts psi are assumed to be either 0 DEG or 180 DEG . Although the hypotheses result in some attenuation of the resultant combined multipath signal R, when compared to an ideal filter (58), a significantly enhanced output is achieved without requiring detailed information about the environment. Both hardware and software implementations of the filter are disclosed.
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