VisSim/Comm™ | VisSim

By: Visual Solutions  11-11-2011
Keywords: Modeling, System Design, Development Platform

Adaptive equalization compensating for channel distortions in a 16-QAM comms link

Based on the core VisSim engine, VisSim/Comm) is used for the modeling and simulating end-to-end communication systems at the signal or physical level. With a full complement of communication blocks and a powerful, time-domain simulation engine, VisSim/Comm provides fast and accurate solutions for analog, digital, and mixed-mode communication system designs. The communication block set includes RF, UWB, Bluetooth, 802.x, Turbo Codes, Costas loop, PLL, VCO, BPSK, QPSK, DQPSK, QAM, BER, Eye Diagram, Viterbi, Reed-Solomon and much more. VisSim/Comm was rebadged as "Commsim" by Electronic Workbench and sold by them for a number of years.

Typical Data Communication Link Simulation

Using VisSim/Comm, you can freely move among the stages of model construction, simulation, optimization, and validation. This tightly integrated development platform allows you to simulate and view signal waveforms at any stage of the communication system chain. And all modeling and simulation tasks can be completed without writing a line of code. In short, VisSim/Comm makes it easy to build, modify and maintain even the most complex system models. Ericsson Inc., a leading developer and manufacturer of cellular and PCS consumer electronics, has been using VisSim/Comm for years in their research and development efforts.

Transmitter and Receiver Models

Communication system design can be divided into two categories: transmitter design and receiver design. VisSim/Comm lets you build both transmitter and receiver models, from a first principles perspective, by simply selecting and connecting predefined blocks. You can construct a wide range of models including analog, digital and mixed mode designs, and quickly simulate their behavior. The VisSim/Comm block set provides a variety of modulators and demodulators, including standard analog, PSK, QAM and differential formats. Full support is also provided for the design of phase locked loops, including loop filter and VCO elements.

Encoders and RF Components

For designs where encoding is required, VisSim/Comm supports both conventional coding techniques (convolutional, Reed-Solomon, trellis-based) as well as more advanced methods such as the UMTS or LTE Turbo Codes. In addition, for designs that require the modeling of RF components, VisSim/Comm provides models for amplifiers, mixers, splitters, attenuators, couplers, and switches, including noise figure and nonlinear effects.

Channel Distortion Fading and Echos

VisSim/Comm includes a variety of predefined channel models supporting both fixed and mobile service scenarios. Included are fading, multipath, bandlimited, and Gaussian noise models:

  • AWGN (real and complex, scalar and vector)
  • Binary Symmetric
  • Jakes Mobile
  • Rummler and standard Multipath
  • Propagation loss
  • Rice/Rayleigh Fading
  • Saleh-Valenzuela (real and complex)
  • TWTA (calculated and table lookup)

You can modify VisSim/Comm block parameters to suit their specific system. You can also create custom models by forming new compound blocks or developing custom blocks using the built-in VisSim block wizard.


Keywords: Communication System, Development Platform, Modeling, System Design

Other products and services from Visual Solutions


VisSim Product Overview | VisSim

VisSim's visual interface offers a simple method for constructing and simulating large-scale complex dynamic systems; its math engine provides fast, accurate solutions for linear, nonlinear, continuous time, discrete time, time varying and hybrid system designs. VisSim is an award winning graphical block diagram language for modeling and simulating complex dynamic systems.


VisSim | VisSim

By combining the simplicity and clarity of a block diagram interface with a high-performance mathematical engine, VisSim provides fast and accurate solutions for linear, nonlinear, continuous time, discrete time, SISO, MIMO, multi-rate, and hybrid systems. VisSim's tightly integrated development platform makes it easy to pass freely among the stages of model construction, simulation, optimization, and validation.


VisSim/Turbo Codes™ | VisSim

The optional VisSim/TurboCodes module brings the power of Turbo Codes to VisSim/Comm simulations by adding support for the PCCC variety of turbo codes. Exhibiting performance approaching the Shannon limit, Turbo Codes have seen rapid adoption in the design of modern digital communication systems. The TC blockset features efficient encoder and decoder designs, including support for the UMTS specification.


VisSim/ECD for TI Piccolo | VisSim

VisSim/Fixed Point block set performs simulation and efficient code generation of scaled fixed-point operations like sin, cos, sqrt, atan2, FIR, and IIR; overflow and precision loss effects are easily seen and corrected at simulation time; auto-scaling speeds fixed-point development; in-line code generation creates fast target code.