Digitizing ultra-wideband OFDM signals with frequency channelization

Abstract

While OFDM emerges as a potential solution for high data rate ultra-wideband (UWB) systems, the primary implementation challenge is the design of the high-speed ADC. In this paper, an efficient and fast adaptive frequency channelized receiver structure for OFDM is proposed. The cyclic prefix (CP) in OFDM signals enable the channelizer and the propagation channel to be decomposed into DFT related matrices and two cascaded equalizers corresponding to the channelizer and the propagation channel. A novel decomposition of DFT matrix is proposed to reduce the complexity of the cascaded receiver structure. The cascaded equalization structure enables the receiver to quickly track variations in the propagation channel. Simulations show that the proposed receiver achieves comparable uncoded bit error rate (BER) as an ideal fullband OFDM receiver