Stream Length

• Definition:
  The stream length is the number of message words that will be generated for the simulation. It corresponds to the length of the trellis.
  
• Usage:
  The length of the trellis may not be exactly the same value that you enter for the stream length. It will be the greatest multiple of the Trace Length that is less than or equal to the value you enter.Be wary of starting a simulation with a very long stream length. This might take a while to generate.
  
• Valid Input:
  Obviously the stream length must be greater than zero for anything to happen. Also, it should be at least as long as it takes to do one trace back operation. Since the Workshop is designed as a tool to show HOW the Viterbi algorithm works and not to analyze the statistics of simulations, it was not designed to be optimized for speed or memory consumption. It uses a lot of memory because the entire trellis is kept in memory for the duration of a simulation so you can view any part of the entire trellis at any time. It is for this reason that an arbitrary upper limit on the stream length has been set at 500 trellis sections. In real applications, only the length of the trellis needed for one trace back operation is kept in memory at any one time.