119 results about "Bit interleaved coded modulation" patented technology

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 16200 and a code rate of 3 / 15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for quadrature phase shift keying (QPSK) modulation.

The invention relates to a frequency hopping fountain code system and a transmission method thereof, in particular to a transmission method of a frequency hopping fountain code system introduced by using a novel interweaving technology, and belongs to relevant technical fields of wireless communication systems, communication signal processing, channel coding and decoding and the like. The frequency hopping fountain code system can be used for transmitting data under the condition that a part of frequency points are blocked completely under the action of interference, so that the reliability of a communication system in a severe channel environment is enhanced. A bit-interleaved coded modulation technology is adopted, so that the bit error rate performance of the system is improved. Meanwhile, the redundancy is not increased, so that the rate of information transmission is not influenced. A bit-level interleaver is adopted, and can be used for encrypting under the condition that an interleaving rule cannot be obtained by an enemy, so that the safety of information transmission is enhanced.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 2 / 15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for 64-symbol mapping.

An efficient system and method for modulation and demodulation to achieve a high data rate using Bit-Interleaved Coded Modulation and OFDM uses either a coherent or a non-coherent transmission scheme using differential modulation. In order to maintain a high data rate impervious to sudden phase changes, a communication system uses an efficient constellation having multiple rings with different sizes and modulation / demodulation schemes utilizing this constellation. In power line communications, the channel gain information is obtained easily at a receiver (100) while the phase information is not. Thus, the communication system uses an absolute magnitude and differential phase coding for modulation and demodulation of the signals.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 4 / 15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for quadrature phase shift keying (QPSK) modulation.

A DVB-H bit-interleave coded modulation / demodulation system and method includes a convolutional encoder; an interleaver operatively connected to the convolutional encoder; a quadrature amplitude modulation (QAM) mapper operatively connected to the interleaver; a channel component operatively connected to the QAM mapper; a QAM demapper operatively connected to the channel component; a de-interleaver operatively connected to the QAM demapper; and a Viterbi decoder operatively connected to the de-interleaver. Preferably, the interleaver comprises a bit-wise interleaver and a symbol-wise interleaver operatively connected to the bit-wise interleaver. Preferably, the de-interleaver comprises a bit-wise de-interleaver; and a symbol-wise de-interleaver operatively connected to the bit-wise de-interleaver. The de-interleaver may be adapted to decode a soft decision metric for any of a QPSK, 16QAM, and 64QAM modulation. The de-interleaver may be adapted to decode a soft decision metric computation comprising a log-likelihood ratio soft decision metric of a binary bit stream of a signal.

The invention discloses a method for encoding and modulating a physical frame signaling channel in an NGB-W system. The method comprises the following steps of: adding CRC (cyclic redundancy code) bits to physical frame signaling and scrambling the physical frame signaling; mapping the scrambled physical frame signaling into BCH (Broadcast Channel) code information bits; performing forward error correction coding to the BCH code information bits by BCH coding and LDPC (Low Density Parity Check) coding cascade methods; generating physical frame signaling check bits and forming physical frame signaling coding blocks; performing constellation mapping to the physical frame signaling coding blocks to generate BICM (Bit Interleaved Coded Modulation) blocks. The method is characterized in that a forward error correction coding solution with a reasonable structure and parameters, and LDPC codes including a QC-Raptor-Like structure and approaching a Claude Elwood Shannon threshold are adopted, and bit mapping of information with the changeable signaling length, code rate control and coding block generation can be supported; the physical frame signaling with the changeable length can be protected so that the transmission reliability of the physical frame signaling is relatively steady along with the change of the signaling length.

A method and apparatus for tree position adaptive SOMA receiver structures are disclosed herein. In one embodiment, a device for use in a wireless communication system comprises a receiver to receive information-bearing signals from the transmitter wirelessly transmitted using OFDM and bit interleaved coded modulation, where the receiver includes an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each tone, and wherein the SOMA-based MIMO joint demapper is operable to search a detection tree for each tone using a tree-search symbol order that is adapted for each tone based on channel state information and extrinsic information from the outer decoder, where only a number of best alternatives from every level of the tree are expanded.

Methods and systems using a Gray-like labeled QAM cross-constellation are disclosed. In some embodiments a Gray-like labeled QAM cross-constellation is used in wireless communication systems.