Generalized Successive Interference Cancellation/Matching Pursuits Algorithm for DS-CDMA Array-Based Radiolocation and Telemetry

摘要

A radiolocation problem using DS-CDMA waveforms with array-based receivers is considered. It is assumed that M snapshots of N_(s) Nyquist sample long data are available, with a P element antenna array. In the handshaking radiolocation protocol assumed here, data training sequences are available for all K users. As a result, the received spatial-temporal matrix R E C~(MN_(s)XP) is approximated by a sum of deterministic signal matrices S_(k)~(b) E C~(MN_(s)XN_(s)) multiplied by unconstrained array response matrices A_(k) E C~(N_(s)XP). The unknown delays are not estimated directly. Rather, the delays are implicitly approximated as part of the symbol-length long channel, and solutions sparse in the rows of A are thus sought. The resulting ML cost function is J velence ||R - sum from k=1 to K of S_(k)~(b) A_(k||F). The Generalized Successive Interference Cancellation (GSIC) algorithm is employed to iteratively estimate and cancel multiuser interference. Thus, at the k-th GSIC iteration, the index p_(k) velence arg min_(l(not=)p_(1),...,p_(k-1)) {min_(A_(l)) ||R~(k) -^sS_(l)~(b) A_(l||F)} is computed, where R~(k) velence sum from l=1 to k-1 of S_(p_(l))~(b) A_(p_(l)). Matching pursuits is embedded in the GSIC iterations to compute sparse channel/steering vector solutions A_(l). Simulations are presented for DS-CDMA signals received over channels computed using a ray-tracing propagation model.