Study of Probe Signal Properties Influence on Coherence Bandwidth Estimation for Underwater Acoustic Communication Channel
* Presenting author
A signal transmitted in a shallow underwater acoustics communication channel suffers from time dispersion due to the multipath propagation and the refraction phenomenon. This causes the intersymbol interference, the consequence of which is frequency-selective fading observed in the frequency response of the channel. Coherence bandwidth defines maximal bandwidth, wherein the channel amplitude characteristic remains constant and its phase characteristic is linear. It can be calculated on the basis of the channel impulse response, measured with the use of the correlation method and frequency modulated signals or pseudorandom binary sequences. Probe signals have a narrow, impulse-like autocorrelation function if considered in baseband. However, in the case of passband impulse response measurement, the influence of the probe signal on the estimate of impulse response, and thus on the estimate of coherence bandwidth, is no longer negligible. The paper presents the results of simulations and measurements conducted in an inland reservoir.