Revised SNR Estimator in DSSS Receiver Based on Curve Fitting

In a QPSK modulated DSSS receiver, a novel SNR estimator is introduced along with its implementation in FPGA devices. To improve the estimator´s precision, an algorithm based on curve fitting is applied. The estimated amplitude and amplitude offset is treated as independent variable and dependent variable respectively, and a curve fitting tool is used to get the modification of SNR estimation. The precision of SNR estimation is improved remarkably by modifying the original SNR estimation according to the modification. Finally the performance is tested and analyzed.