If you have an inner and outer code that would be the situation, but I'm not sure that flipping one bit would always be accurate. A Viterbi decoder might generate small bursts of errors. HDTV uses TCM with an outer Reed-Solomon code. Even though there are 12 interleaved convolutional encoders, they still use an RS code that is capable of correcting bursts of 8 errors.
73, John KD6OZH ----- Original Message ----- From: Rud Merriam To: digitalradio@yahoogroups.com Sent: Tuesday, November 06, 2007 20:10 UTC Subject: RE: [digitalradio] Testing Digital Codes at Bit Level I understand about the use of soft decoders. If the protocol uses a soft decoder and another hard decoder the latter works at the bit level. A standard example is using Reed-Solomon for the hard decoder. Would the bit flipping be representative of the atmospheric effects for the outer hard decoder, e.g. RS decoder? Rud Merriam K5RUD ARES AEC Montgomery County, TX http://TheHamNetwork.net
