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
Digital Signal and Image Processing Using MATLAB
The most important theoretical aspects of image and signal processing (ISP) for both deterministic and random signals are covered in this guide to using MATLAB® . The discussion is also supported by exercises and computer simulations relating to real applications such as speech processing and fetal-heart–rhythm tracking, and more than 200 programs and functions for numerical experiments are provided with commentary.
This chapter contains sample programs for determining capacity. The reader is advised to go through the coding. The
file "capacity_water.m" is for measuring the waterfilling capacity. It should be made to work with a file similar to
"capacity_plot_main.m". The latter file deals with all the other capacity plots given in the book in Chapter 2.
All programs are verified with MATLAB versions 6.0 and above with signal processing and communications toolboxes.
he algorithm is equivalent to Infomax by Bell and Sejnowski 1995 [1] using a maximum likelihood formulation. No noise is assumed and the number of observations must equal the number of sources. The BFGS method [2] is used for optimization.
The number of independent components are calculated using Bayes Information Criterion [3] (BIC), with PCA for dimension reduction.
The TMS320C54x, TMS320LC54x, and TMS320VC54x fixed-point, digital signal processor (DSP) families
(hereafter referred to as the ’54x unless otherwise specified) are based on an advanced modified Harvard
architecture that has one program memory bus and three data memory buses. These processors also provide
an arithmetic logic unit (ALU) that has a high degree of parallelism, application-specific hardware logic, on-chip
memory, and additional on-chip peripherals. These DSP families also provide a highly specialized instruction
set, which is the basis of the operational flexibility and speed of these DSPs.
As you have learnt that sleep( )/usleep()/nanosleep() are not good to delay a process. Timers can provide more accurate time control in applications. In this lab, you will explore POSIX timers and signal programming, experience the timer drift.
The primary focus of this lab will be "time". The experiment will show you several methods to measure time in your applications.
The MEASURE program uses the analog inputs of the P89LPC935
to implement a datalogger. This example shows how you can
use signal functions in uVision to simulate a signal coming
into one of the analog inputs of the P89LPC935 controller.
Description The MUSIC algorithm, proposed by Schmidt, first estimates a basis for the noise subspace and then determines the peaks the associated angles provide the DOA estimates.
The MATLAB code for the MUSIC algorithm is sampled by creating an array of steering vectors corresponding to the angles in the vector angles.
ECE345, Visual-to-Audio Electronic Travel Aid
Code for TM320C54x (v2a.asm) download
This project involves the design and implementation of a audio synthesis device that converts moving images into audio signals. The system is built on a TM320C54x DSP with interface to an IMAQ camera module via the serial port on a PC. Brief description: A LabVIEW VI acquires an image from the IMAQ camera module. It quantizes the image into a 5x5, 3-bit image, and sends the data to the TM320C54x DSP via a serial port. The TM320C54x DSP constructs a 64-tap FIR by combining a series of 64-tap head related transfer functions (HRTF) according to the incoming data, and then filters an input audio signal with this FIR filter, in effect creating a correspondence between the filtered signal and the original image.
This document describes how to switch to and program the unisersal serial bus (USB)
analog phase-locked loop (APLL) on the C5506/C5507/C5509A devices. Example
assembly programs for programming and switching to and from the APLL are also
provided in the attached zip file. It is assumed that the reader is familiar with the use
and operation of the C5506/C5507/C5509A USB digital phase-locked loop (DPLL) and
C55x™ Digital Signal Processor (DSP) IDLE procedures.
