Simplified Ranging Systems Using Discrete Wavelet Decomposition
We employ the concepts and tools of the discrete wavelet transform (DWT) to encapsulate a body of previous research on efficiently analyzable phase-coded waveforms for use in ranging applications. This DWT perspective enables the direct synthesis of half-rate implementations which are suitable for high-speed applications. We introduce and study a set of sequences, based on a classical Welti construction, which are both DWT-decomposable and exhibit a zero autocorrelation zone property under cyclic extension. We propose a general extension technique which extends the zero correlation width while retaining the same simple receiver filter, and show that this technique is appropriate for many of the sequences in our construction. Finally, we propose a transmit waveform construction which allows a further reduction of two in the receiver hardware complexity. We discuss the resulting tradeoffs between receiver complexity and transmit power.