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ZORAN PERIC, ALEKSANDAR MOSIC AND STEFAN PANIC
Department of Telecommunications
University of Nis
18000 Nis, Serbia
This paper proposes a novel coding algorithm based on loss compression using scalar
quantization switching technique. The algorithm of switching is performed by the estimating
input variance and further coding with Nonuniform Switched Scalar Compandor
(NSSC). An accurate estimation of the input signal variance is needed when finding the
best compressor function for a compandor implementation. It enables quantizers to be
adapted to the maximal amplitudes of input signals. Additionally, we have discussed the
performances of coding schemes designed according to waveform G.711 and G.712
standards and a novel presented codec standard for wideband speech and audio coding.
We have pointed out the benefits that can be achieved by using our algorithm: raise of
quality and compression. The main contribution of this model is reaching the loss compression
through reaching the higher quality of the signal-to-quantization noise ratio
(SQNR) in a wide range of signal volumes (variances) with respect to the necessary robustness
over a broad range of input variances, and applying possibility for VOIP applications
and an effective coding of signals that likewise speech signals follow Gaussian
distribution and have the time varying characteristics.
Received September 29, 2008; revised April 21, 2009; accepted June 4, 2009.
Communicated by Liang-Gee Chen.