Zhang Qunying

The Applying of Compressed Sensing in M-Sequence UWB Radar

A maximum length binary sequence, in short an M-sequence, is a special kind of pseudo-random binary sequence(PRBS). It can be well used in Ground Penetrating Radar(GPR) because of advanced characteristics. Compressed Sensing(CS) provides a way to sample the signal below the Nyquist rate, but it relies on two principles: sparsity, which pertains to the signals of interest, and incoherence, which pertains to the sensing modality. M-sequence matrix has been proved satisfying RIP property. In this paper we will introduce a M-sequence GPR system and the CS theory will be used to reconstruct the signal when the original signal is extracted. The experiment results will also be given.

Adaptive calibration of I and Q mismatch in quadrature receiver

The mismatch of in-phase and quadrature channels in quadrature receiver affects and constrains radar detection performance in colierent radar. It is necessary to keep the in-phase and quadrature branches symmetrical. In this letter, an adaptive method to detect imbalance parameters is derived by means of evaluating channel errors from the received signal sequences. No matter how the bias degree of the gain and phase errors in I/Q channels are, the proposed adaptive scheme can obtain good calibration results. And the required calculations are only a few multiplications and additions. No need of a special test signal, the introduced method is simple to implement and easy to operate.