Coarse quantization for data compression in coherent location systems

• Published in: IEEE transactions on aerospace and electronic systems Vol. 36; no. 4; pp. 1269 - 1278
• Main Author: Fowler, M.L.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustic measurements; Additive white noise; Aircraft components; AWGN; Coherence; Data compression; Doppler effect; Electronic systems; Gaussian noise; Optimization; Position (location); Quantization; Signal analysis; Signal processing; Signal to noise ratio; Transmitters
• ISSN: 0018-9251; 1557-9603
• DOI: 10.1109/7.892674

When emitter location systems measure time-difference-of-arrival (TDOA) and differential Doppler (DD) by coherently cross-correlating the signal pairs, data compression techniques are needed to facilitate data transfer of one of the signals to the receiving site of the other signal. Two block-adaptive quantization schemes are analyzed here to determine their impact on the signal-to-noise ratio (SNR) of the quantized signal as well as on the post-correlation SNR. Comparisons are made between two approaches: quantization of the real/imaginary (R/I) components or the magnitude/phase (M/P) components. For the M/P approach, a rule is derived for optimally allocating the bits between the magnitude and phase. The M/P approach provides better post-quantization/precorrelation SNR for most signals; however, when the SNR of the signal not being quantized is small, the post-correlation SNR can be largely unaffected by the quantization. In that case, there is little difference between R/I and M/P, even under the most favorable scenario for M/P.