System and method for communicating data using iterative equalizing and decoding and recursive inner code
View Patent ↗A system and method for communicating data includes an inner encoder for encoding data with the recursive inner rate one code. A modulator coherently modulates a communications signal that carries the data that has been encoded. An interleaver is operative with the inner encoder and modulator to aid in removing correlation of multipath fading channels on consecutive bits. A convolutional encoder is followed by a random interleaver. The modulator can be operative with mini-probe sequences. An equalizer and decoder receives the communications signal and iteratively decodes any recursive inner rate one code and convolutional code in a turbo fashion.
1. A method of communicating data which comprises:
transmitting data over a communications channel by generating a waveform that uses a serial concatenation of a convolutional code, a recursive inner rate one code and coherent modulation and by adding a preamble and mini-probe sequence selected from pseudo-random sequences during modulation to aid in removing correlation of multipath fading channels on consecutive bits; and
receiving the communications signal and iteratively decoding the recursive inner rate one code and convolutional code in a turbo fashion to obtain the data by equalizing the received communications signal within an equalizer followed by interleaving within an inner deinterleaver and decoding within a rate one decoder and feeding back a portion of the signal from the rate one decoder to an inner interleaver and back into the equalizer and followed by outer deinterleaving and decoding in an outer forward error correction (FEC) decoder and feeding back a portion of the signal from the FEC decoder to the rate one decoder such that any inner rate one code and outer convolutional code are iteratively decoded in turbo fashion and equalization is redone with iterations through the signal feedback with any latest demodulated symbol estimates resulting from the turbo process and continuing the turbo decoding process with improved equalizer estimates.
2. A method according to claim 1 , which further comprises generating multiple bits for transmission based on a coherent modulation.
3. A method according to claim 1 , which further comprises equalizing after every few iterations.