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A novel method of compressing speech with higher
bandwidth efficiency
This uses a novel method of speech compression and transmission. This
method saves the transmission bandwidth required for the speech signal by
a considerable amount. This scheme exploits the property of low pass
nature of the speech signal. Also this method applies equally well for any
signal, which is low pass in nature, speech being the more widely used in
Real Time Communication, is highlighted here.
As per this method, the low pass signal (speech) at the
transmitter is divided into set of packets, each containing, say N number
of samples. Of the N samples per packet, only certain lesser number of
samples, say N alone are transmitted. Here is less than unity, so
compression is achieved. The N samples per packet are subjected to a
N-Point DFT. Since low pass signals alone are considered here, the number
of significant values in the set of DFT samples is very limited.
Transmitting these significant samples alone would suffice for reliable
transmission. The number of samples, which are transmitted, is determined
by the parameter .
The parameter is almost independent of the source of
the speech signal. In other methods of speech compression, the specific
characteristics of the source such as pitch are important for the
algorithm to work.
An exact reverse process at the receiver reconstructs
the samples. At the receiver, the N-point IDFT of the received signal is
performed after necessary zero padding. Zero padding is necessary because
at the transmitter of the N samples only N samples are transmitted, but at
the receiver N samples are again needed to honestly reconstruct the signal
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