Error Correction Coding for Channels Subject to Occasional Losses of Bit Count Integrity

An error correction coding device has been developed that combines the functions of forward error correction with interleaving for burst and random error protection, and the ability to detect and correct for bit count integrity losses out of the demodulator. The burst errors and bit count integrity losses are a result of various perturbations on the communication channel that result in the demodulator failing to correctly track the carrier. This problem is particulary noticeable in offset QPSK modulation. Data is presented showing improved burst error and bit integrity performance for this codec when interfaced to an MD-1002/G offset QPSK modem. The results indicate that bit count integrity can be maintained under severely degraded channel conditions where bit integrity would otherwise have been lost.