|標題:||Performance Analysis of a Complex Multicode Tracking Loop in Bandlimited Rayleigh Fading Channels|
|作者:||Hsu, Nicolas Y. -H.|
Su, Yu T.
Department of Electronics Engineering and Institute of Electronics
Institute of Communications Engineering
|關鍵字:||Code tracking;Complex multicode spreading;Bandlimited fading|
|摘要:||This paper presents the root-mean-squared tracking error performance analysis of a class of coherent digital delay-locked loops for multicode direct sequence spread spectrum signals in bandlimited correlated Rayleigh fading channels. In the transmit side, multiple independent PSK-modulated data streams in the in-phase and qudrature phase branches are spread by short mutually orthogonal codes before being further complex spread by a long complex PN code. We assume that the system employs a pilot code channel to assist the receiver's synchronization and channel estimation. The proposed code tracking loop incorporates the pilot-aided channel estimator and derives the timing error from all short-code-spread subchannels. Our analysis takes into account the effects of imperfect channel estimate, correlated frequency selective Rayleigh fading and band-limiting. Numerical results are presented to quantify the impact of the resulting multipath interference within the same code channel and amongst different code channels.|
|期刊:||WIRELESS PERSONAL COMMUNICATIONS|