An Effective Joint Implementation Design of Channel Equalizer and DDC for WDAR Receiver

Abstract: In this paper, the technique of digital down conversion (DDC) and channel equalization in wideband digital array radar (WDAR) are introduced. The analysis about the frequency domain equalization algorithm based on weighted least squares (WLS) is derived in detail at first. Then, an efficient DDC based on polyphase structure with intermediate frequency (IF) bandpass sampling is presented. Moreover, a simple structure which combines equalizer and DDC is proposed, which is proven to be valid, feasible and efficient. A design example is given and the FPGA resource consumption saving is discussed also. The corresponding simulations and test results demonstrate the effectiveness of the proposed DDC and show that the performance of the channel mismatch after equalization is improved obviously.