This Product Review appeared in Wireless Systems Design in September 1997.
Managing the flow of information between a base station and a portable device is a concern for all system designers. To help check the flow of information, engineers have turned to software tools which analyze the movement of signals and data through a system. To aid designers in this analysis, the DADiSP 4.0 personal-computer (PC) program developed by DSP Development Corp. (Cambridge, MA) is equipped with more than 800 math functions which analyze and manipulate data.
DADiSP 4.0 displays data from ASCII or binary data formats or from external measurements and acquisition devices. This visually-oriented program is an interactive graphics worksheet which is comprised of as many analysis windows as the engineer needs. In fact, the program allows engineers to simultaneously display 100 windows on screen.
Each window can contain raw data or data (displayed as a graph or table) transformed by one of DADiSP's analysis functions. Through formulas, the data and graphs in each window can be linked to the data and graphs in other windows. As a result, any changes to data or graphs in one window cause automatic calculations and updates to be performed in all dependent windows.
In the worksheet environment, data can be evaluated from different points of view. Engineers can view data as a line graph, a scatter plot, a stick chart, a bar chart, a waterfall plot, a 3D plot, 4D colorization, or as a basic table of numbers. Using this software program, engineers can dynamically scroll, expand, or compress data in any direction. To do this, the designer zooms in, through a click of a mouse, on any region of interest, adds grids, and includes scales and engineering units.
An enhanced graphical-user interface (GUI) and individual window enables engineers to manage and interpret technical data visually and interactively. Results can be examined with a magnifying glass, cursors, or by scrolling or paging through the windows.
DADiSP is equipped with a series-processing language (SPL), a C-like programming language. SPL provides user-designed functions, looping and iteration, condition statements, array references, and variables. With SPL, designers can write custom functions and applications for their worksheets.
A variety of optional support packages are available for the software package, including an advanced DSP Module, a filter module, and a GPIB drive module.
DADiSP/AdvDSP is a menu-driven advanced DSP module which performs a variety of DSP algorithms such as Fast Fourier transform (FFT) analysis, power-spectral density estimation, digital interpolation, and cepstrum analysis. This module provides digital interpolation techniques for changing the sampling rate, which can be any desired rate that the engineer seeks.
To ease the evaluation process, an optional GPIBLab menu-driven software module is offered. This module collects data from test equipment that is equipped with a GPIB interface. Without programming or configuration, this data is displayed in the multi-window worksheet environment where it can be evaluated and adapted by the engineer.
By adding the optional DADiSP/Filters digital filtering module to DADiSP, engineers obtain full finite-impulse-response (FIR) and infinite-impulse response (IIR) filtering capabilities on top of the worksheet. The FIR module creates lowpass, highpass, bandpass, bandstop, and multi-band filters as well as Hilbert transformers and differentiators using the Parks-McClellan/Remez Exchange optimal design algorithm. The IIR module, on the other hand, supports Butterworth, Chebychev I and II, and elliptic designs for lowpass, highpass, bandpass, and bandstop recursive filters.
DADiSP 4.0 is designed for PCs for all Windows platforms including Windows 95 and Windows NT. The program is also available under the X-Windows Motif on workstations from Sun, Hewlett-Packard, IBM, Digital Equipment, NeXT, SGI. A 30-day free trial is available for the product. P &A: $1,995 (stock).
DSP Development Corp., One Kendall Square, Cambridge, MA 02139; (617) 577-1133, Fax: (617) 577-8211, e-mail: dspdev@world.std.com, WWW: http: //www.dadisp.com.
Robert Keenan
Wireless Systems Design
Copyright 1997 Penton Publishing, Inc.
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