Description: Abstract-The effect of the companding process on QAM signals
has been under investigation for the past several years. The
compander, included in the PCM telephone network to improve
voice performance, has an unusual affect on digital QAM data
signals which are transmitted over the same channel. The quantization
noise, generated by the companding process which is multiplicative
(and asymmetric), degrades the detectability performance
of the outermost points of the QAM constellation more
than that of the inner points.
The combined effect of the companding noise and the inherent
white gaussian noise of the system, leads us to a re-examination of
signal constellation design.
In this paper we investigate the detectability performance of a
number of candidates for signal constellations including, a typical
rectangular QAM constellation, the same constellation with the
addition of a smear-desmear operation, and two new improved
QAM constellation designs with two-dimensional warpi Platform: |
Size: 1076882 |
Author:雨笑了 |
Hits:
Description: The µ -law algorithm (pronounced myoo-law) is a companding algorithm, primarily used in the digital telecommunication systems of North America and Japan. As with other companding algorithms, its purpose is to reduce the dynamic range of an audio signal. In the analog domain, this can increase the signal-to-noise ratio (SNR) achieved during transmission, and in the digital domain, it can reduce the quantization error (hence increasing signal to quantization noise ratio). These SNR increases can be traded instead for reduced bandwidth for equivalent SNR. Platform: |
Size: 966744 |
Author:junwang |
Hits:
Description: Abstract-The effect of the companding process on QAM signals
has been under investigation for the past several years. The
compander, included in the PCM telephone network to improve
voice performance, has an unusual affect on digital QAM data
signals which are transmitted over the same channel. The quantization
noise, generated by the companding process which is multiplicative
(and asymmetric), degrades the detectability performance
of the outermost points of the QAM constellation more
than that of the inner points.
The combined effect of the companding noise and the inherent
white gaussian noise of the system, leads us to a re-examination of
signal constellation design.
In this paper we investigate the detectability performance of a
number of candidates for signal constellations including, a typical
rectangular QAM constellation, the same constellation with the
addition of a smear-desmear operation, and two new improved
QAM constellation designs with two-dimensional warpi Platform: |
Size: 1076224 |
Author:雨笑了 |
Hits:
Description: Quantization (signal processing)
uniformly and non-uniformily using A and miu law od companding.
simulation using simulink/matlab Platform: |
Size: 10240 |
Author: |
Hits:
Description: Companding is essentially a technique for achieving non-uniform quantization. There are basically 2 methods which are most popular in literature.:-A-law companding and u-law companding. These algorithms help in achieving to an extend, compression. The given code shows how to compress a 14-bit code to 8-bit code and its digital implementation using matlab. Please contact by mail if a detailed description of code is needed. Platform: |
Size: 1024 |
Author:shanil |
Hits:
Description: For a file(.wave)
• Find the sampling frequency and the number of bits per sample.
• Re-quantize the samples using the following methods:
o Linear Quantization
o A-Law Companding with A=87.6
o μ-Law Companding with μ=255
• Use a mid-rise quantizer with 4, 5, 6, 7, and 8 bits per sample.
• Obtain the signal-to-quantization noise ratio (SQNR) for each of the
above 15 cases.
• It is required to plot the SQNR (dB) versus the number of bits per
sample for linear quantization, A-law companding, and μ-law
companding. All 3 plots may be on the same figure, if convenient.
-For a file(.wave)
• Find the sampling frequency and the number of bits per sample.
• Re-quantize the samples using the following methods:
o Linear Quantization
o A-Law Companding with A=87.6
o μ-Law Companding with μ=255
• Use a mid-rise quantizer with 4, 5, 6, 7, and 8 bits per sample.
• Obtain the signal-to-quantization noise ratio (SQNR) for each of the
above 15 cases.
• It is required to plot the SQNR (dB) versus the number of bits per
sample for linear quantization, A-law companding, and μ-law
companding. All 3 plots may be on the same figure, if convenient.
Platform: |
Size: 1024 |
Author:mshmsha |
Hits:
Description: pcm编码A律Simulink和MATLAB(PCM in the communication system to complete the voice signal digital function, and its implementation mainly includes three steps to complete: sampling, quantization, coding. The binary representation of time discrete, amplitude discrete and quantized signals is completed respectively. According to CCITT, in order to improve the performance of small signal quantization, using companding non-uniform quantization, there are two suggestions, respectively A law and the law of our country, using the A law, the A law compression complex, often using 13 line method for encoding, using non uniform quantization coding PCM.) Platform: |
Size: 32768 |
Author:面包不面
|
Hits:
Search - companding quantization