A Nonlinearity Mitigation Method for a Broadband RF Front-End in a Sensor Based on Best Delay Searching

Abstract

The cognitive radio wireless sensor network (CR-WSN) is experiencing more and more attention for its capacity to automatically extract broadband instantaneous radio environment information. Obtaining sufficient linearity and spurious-free dynamic range (SFDR) is a significant premise of guaranteeing sensing performance which, however, usually suffers from the nonlinear distortion coming from the broadband radio frequency (RF) front-end in the sensor node. Moreover, unlike other existing methods, the joint effect of non-constant group delay distortion and nonlinear distortion is discussed, and its corresponding solution is provided in this paper. After that, the nonlinearity mitigation architecture based on best delay searching is proposed. Finally, verification experiments, both on simulation signals and signals from real-world measurement, are conducted and discussed. The achieved results demonstrate that with best delay searching, nonlinear distortion can be alleviated significantly and, in this way, spectrum sensing performance is more reliable and accurate.

Phase nonlinearity reduction of a complex receiver having multiple phase correlators

“…Extensive works have been reported regarding ultra wideband IFM receiver design techniques to track the unknown frequencies with very good resolutions [6][7][8][9][10][11][12]. Sarkar et al shows a detailed investigation of a double-sided assembly where abrupt phase nonlinearity has been explained [1].…”

“…The proposed technique in this article is very complex, where five simultaneous channels have been used to compare phase deviations over a wideband of frequencies (1-10 GHz). A nonlinearity mitigation technique for a broadband front-end receiver has been proposed by Zhao et al in [7]. In this method, the input RF signal is digitized first and then passed through the best delay searchingpower residuals optimization circuit.…”

“…A nonlinearity mitigation technique for a broadband front-end receiver has been proposed by Zhao et al. in [7]. In this method, the input RF signal is digitized first and then passed through the best delay searching–power residuals optimization circuit.…”