Silicon DSP Corporation

Capsim provides the capability to simulate complex systems in batch mode. This is in addition to using the built in TCL interpreter. Basically, since Capsim can be run via the console command mode by supplying a topology describing the system, powerfull system scripting tools can be used to do iterative simulations. These iterative simulations can change a single parameter at a time or multiple parameters. In this way, Capsim can be used in the design of systems using simulated annealing or other optimization techniques.

As an example we provide a setup in which Capsim is used to simulate the Bit Error Rate (BER) performance of a digital communication link using QPSK modulation. A screen shot of the simulation is shown here . Using Perl as the scripting tool, we write a Perl script that changes the noise level and the number of bits to simulate and measure the BER. The Perl script sets up two lists. One for the noise levels and one for the number of bits to use for each noise level. Obviously it makes sense to use less bits when the noise level is high. This illustrates how any iterative simulation using a combination of parameters can be setup. The Perl script reads in a template topology, replaces the paramaters from each pair of elements in the list and generates a new temporary topology. The script then executes the temporary topology to produce results. The bit error estimation star appends each result to a file. So that after all simulations are complete a tabular result is generated. The BER results are shown here .