Reducing pulse compression sidelobes by inversion-amenable code selection

Two alternative filtering approaches (dubbed ldquocode-inverserdquo and ldquoCodeACF-inverserdquo) for reduction of temporal sidelobes are evaluated and compared for practical engineeering application to pulse compression. It is seen that the optimal code pattern for each code length must be discovered as part of a tightly integrated search process that is sensitive to the inverse filter design algorithm and the number of coefficients budgeted. Re-use of codes derived in other contexts has been commonplace in earlier work, but rarely proves optimal. Hence unique application algorithm-specific codes must be sought, with codewords for CodeACF-inverse employment being obtained independently from those for Code-Inverse usage. If CodeACF-inversepsilas greater storage requirement can be accommodated, then it is found to be very significantly superior. A rule-of-thumb that filter length should be about three times the code length is confirmed by measured sidelobe performance when code sequences are chosen to be optimally amenable to inverse filtering.