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摘要

1511201 Radar TELEFONAKTIEBOLAGET L M ERICSSON 19 Nov 1976 [24 Nov 1975] 48460/76 Heading H4D In a phase coded pulse compression radar, e.g. one using a 5 element Barker code b) Fig. 2, simple auto correlation compression of the echo yields range side lobes h). To remove these side lobes, the echo is sampled to give a set of digital values X K . Ideally these could be processed using a digital filter having a Z transformed transfer function H(z) being the inverse of the z-transform C(z) of the code. Due to C(z) having zeroes outside the unity circle |z| = 1, the resultant inverse filter must be unstable. To enable the use of stable filters DF1 and DF2, Fig. 3, the set X K is applied to the first digital filter DF1 with a Z transformed transfer function having its poles corresponding with the zeroes of C(z) which are within the unity circle |z| = 1. The resulting set Y K of digital values is time reversed Y K and then applied to the second digital filter DF2 with a Z transformed transfer function having its poles position corresponding with the inverted values of the zeroes of C(z) outside |z| = 1. The set U K obtained from the second digital filter is then time reversed, U K .