Research On Interference Mitigation Of DS-UWB

The ultra-wide band technology, which was called Impulse Radio, was originally applied in military field. At present, more and more attention is paid to this short distance communication technology along with the FCC's agreement of its civil use. The current ultra-wide band includes two types: multi-band OFDM (MB-OFDM UWB) and direct sequence spread spectrum (DS-UWB). Because MB-OFDM UWB, which is quite mature, is not essentially different from OFDM technology, it is in dominant position in the competition. However, DS-UWB has commercial potential because of its low power and simple equipment and so on.At present, both of these two kinds of UWB are facing the same problem on how to coexistent with the existing narrow band wireless communication system. Compared with MB-OFDM UWB, the interference problem of DS-UWB is more serious, which is mainly because that the interference origin is complex and the solutions are limited. Based on DS-UWB, this article discusses DS-UWB interference origin and the frequency domain solution. Beside, it has studied the antijamming technology in time domain with emphasis.In the study of interference detection technology, this article systematically describes and stimulates energy detection and Spectral Correlation Function (SCF) based plan. This paper proposes an improved program based on autocorrelation function, whose main superiority is that in time domain, the computation load is smaller than SCF and the detection is more accurate.This article selectively analyzes and improves a DAA plan which is based on power auto-adapted pattern. The DAA plan makes improvement in order to avoid interference with the primary consideration and establish the special flow to avoid mistakenly detecting. The improved DAA plan realizes the optimal interference avoiding effect at the price of transmission efficiency. This article has finally simulated two kinds of DAA plans.