VisSim/Turbo Codes™

Turbo Codes UMTS
Universal Mobile Telecommunications System (UMTS) Turbo Code BER Simulation

Turbo Codes constitute a major development in the field of Forward Error Correction(FEC). Exhibiting performance approaching the Shannon limit, Turbo Codes have seen rapid adoption in the design of modern digital communication systems. They are particularly attractive for cellular communication. 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. The TC blockset features efficient encoder and decoder designs, including support for the UMTS specification.

About the VisSim/Turbo Codes Module

The VisSim/Turbo Code module was developed in collaboration with Dr. Matthew Valenti of West Virginia University and provides support for parallel concatenated turbo codes, including the UMTS specification. Additional information is also available at the Iterative Solutions web site.

Decoder Implementation

The VisSim/Comm Turbo Codes decoder is of a flexible design. It allows the user to select the implementation of the max* operator computation, and it provides the option of using dynamic halting.

Since the max* operator constitutes a significant portion of the overall decoder complexity, its implementation directly affects the performance and speed of the decoding process. Four variants of the algorithms are available: log-MAP, max-log-MAP, constant-log-MAP, and linear-log-MAP. Because a decoder rarely requires the maximum number of iterations to converge, using an early stopping criterion will improve throughput. The VisSim/Comm TC decoder uses a simple and effective stopping criteria based on the log-likelihood ratio.
Jump-start your Wireless system designs by making VisSim/Comm Turbo Codes a part of your design cycle.

VisSim/Turbo Codes Block Set

The following blocks are included in the VisSim/Turbo Code module:

  • UMTS Interleaver Generator
  • S-Random Interleaver Generator
  • Generic Turbo Code Encoder (PCCC)
  • Generic Turbo Code Decoder (PCCC)
  • UMTS Turbo Code Encoder
  • UMTS Turbo Code Encoder


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