SINR-optimized Binary Signatures by Linear Search †
Lili Wei, Stella N. Batalama, Dimitrios A. Pados, Bruce W. Suter · 2006
When data symbols modulate a signature waveform/pattern to move across a channel in the pres- ence of disturbance, as in common spread-spectrum (SS) or code-division multiple-access (CDMA) or mul- tiuser ultra-wideband (UWB) communication systems, the signature/spreading code that maximizes the signal-to- interference-plus-noise ratio (SINR) at the output of the maximum SINR filter is the smallest-eigenvalue eigenvector of the disturbance autocovariance matrix. In digital com- munication systems, however, the signature alphabet is finite and digital signature optimization is NP-hard. In this paper, we present a formal search procedure of cost linear in the signature length that returns the maximum-SINR binary signature near lines of least SINR decrease in the Euclidean vector space. The quality of the proposed adaptive binary design is compared against the theoretical upper bound of the complex/real eigenvector maximizer and other known static and adaptive binary signature designs.