초록 ▼

A communications receiver system is presented for detecting burst errors and providing erasure information to the block decoder, thereby effectively doubling the conventional correction capability of the block decoder with only a minimal increase in complexity. In one embodiment, this mechanism take

A communications receiver system is presented for detecting burst errors and providing erasure information to the block decoder, thereby effectively doubling the conventional correction capability of the block decoder with only a minimal increase in complexity. In one embodiment, this mechanism takes the form of a circuit which re-encodes the output of the inner decoder, compares it with the received sequence of code symbols, and flags a portion of the inner decoder output for erasure when an excessive number of code symbol errors are detected. In a second embodiment, this mechanism takes the form of a circuit which makes hard symbol decisions on the channel signal, compares the hard decisions to the channel signal to determine a noise level, and thereafter flags the channel output in regions with excessive noise levels.

대표청구항 ▼

[ What is claimed is:] [1.] A digital communications system comprising:an encoder configured to receive a digital signal and thereafter convert said digital signal to a coded digital signal;a transmission channel through which said coded digital signal is transmitted;an inner convolutional decoder c

[ What is claimed is:] [1.] A digital communications system comprising:an encoder configured to receive a digital signal and thereafter convert said digital signal to a coded digital signal;a transmission channel through which said coded digital signal is transmitted;an inner convolutional decoder coupled to said transmission channel and an outer block decoder coupled to said inner convolutional decoder, wherein the combination of said inner and outer decoders are configured to convert said coded digital signal to substantially said digital signal; andan error detector coupled to both said transmission channel and said inner convolutional decoder for inserting error flags within an intermediate coded digital signal indicative of the presence of errors within said intermediate coded digital signal forwarded from said inner convolutional decoder to said outer block decoder, wherein said error detector comprisesan inner encoder coupled to an output of said inner convolutional decoder; anda comparator coupled to receive an output of said inner encoder and said transmission channel, and to compare the output of the inner encoder with the output of said transmission channel to determine the presence of said errors within said intermediate coded digital signal.