Punctured serial concatenated convolutional coding system and method for low-earth-orbit satellite data communication

A serial concatenated convolutional coding system for a constellation of low-Earth-orbit (LEO) satellites for transmitting input data bits of information is disclosed. The input data bits are systematically outer convolutional encoded (30), producing outer encoded data bits and outer encoded parity bits. Some of the bits of the outer encoded parity bits are remove by a puncturer (32), and the remaining outer encoded parity bits and the outer encoded data bits are bit interleaved (34). The bit interleaved, outer encoded data and remaining parity bits are systematically inner convolutional encoded (36) producing concatenated coded, bit interleaved inner data bits and concatenated coded, bit interleaved inner parity bits. Some of the bits of the concatenated coded, bit interleaved inner parity bits are removed by a puncturer (38), and the remaining concatenated coded, bit interleaved inner parity bits and the concatenated coded, bit interleaved inner data bits are combined (40). Upon receipt by a serial concatenated convolutional decoding system (43), the serially concatenated convolutional coded data and parity bits are iteratively decoded to recover the data bits of information of the original signal. During decoding erasures are inserted (46, 52) for the parity bits removed by puncturing. Decoding is accomplished by soft input, soft output (SISO) modules (48, 54).