Apparatus for and method of robust packet detection and frequency offset estimation

摘要

A novel and useful apparatus for and method of packet detection and carrier frequency offset estimation. The packet detection mechanism is robust to channels and sustains reasonable miss-detect (and false alarm) rates at low SNR values. The mechanism uses a modified combined cross correlation and delay and correlate scheme. A delay and correlate scheme is used in order to handle the effects of multipath while swapping integration and multiplication to increase cross-correlation factors resulting in improved sensitivity in low SNR conditions. Correlation is divided into multiple chains to generate a plurality of partial correlations to observe short patterns in the spread sequence resulting in improved performance in long multipath channels.

主权项

1. A method of packet detection for use in a digital receiver, said method comprising the steps of:
delaying an input sample stream through a plurality of delay elements; calculating a plurality of partial correlations of said plurality of delayed input samples with reference signal samples; calculating an energy branch signal from said input sample stream; performing nonlinear operations on said plurality of partial correlations to obtain a correlation branch signal; and operating decision logic on said energy branch and correlation branch signals to obtain a detection decision.