| Along with the bandwidths of the passive radar and the electronic reconnaissance and other broadband systems are becoming more and more big and they need high sampling rate and a large number of sampling points based on the traditional signal detection method. The compression sampling theory gives a new way to solve this problem.According to the compression sampling theory, combined with the MWC and the channelized structure based on the polyphase filtering, this paper proposes a new digital signal receiver structure. The structure of this receiver consists of the digital mixer module,front low-pass filter module, extractor module, channelized filter module, channel selection module. Firstly, after the discrete sequence of input signal and the Bernoulli sequence of pseudo random binary digital mixing, its spectrum becomes a linear combination of the cycle to the original spectrum shift. At the same time, the combined spectrum is interval distribution.Then let the mixing signal goes through a front low-pass filter. Again let the signal goes through the filter bank based on channelized structure. Finally, we use the channel select module to select R from M roads signal as the compression sampling data.Until now, the scholars still focus on the accurately reconstruction. However, we needn’t restore the original signal when we deal with the radar signal in practical. Sometimes we just get some of the useful information of observation target. Therefore, this article will discusses how to use the MWC to complete the wideband sparse signal detection. The MWC structure is applied in this article for data sampling based on the theory of compressed sampling and then we get eigenvalue decomposition of the covariance matrix on sampling data. According to gaussian white noise covariance matrix eigenvalues of linear distribution characteristics,using the correlation coefficient of eigenvalue to construct signal detection criterion. The simulation results show that compared with conventional method the one proposed in this paper obtains a higher success rate of detection with fewer samples under low SNR.The UWB signal has lots of advantages, for examples, it is not sensitive to the channel fading, low transmitting power spectral density, low intercept capability and it can provide positioning accuracy of a few centimeter. So it is often used in the military communication.The research of UWB signal detection is of great significance. This paper put forward energy detection for the UWB signal based on the MWC structure. By comparing with the traditional energy detection method, this method still has good detection performance under the low SNR. |
