摘要:
A device for generating quasi-orthogonal codes which allow the minimum interference with orthogonal codes in a mobile communication system using the orthogonal codes. The device includes a first spreader for spreading at least one input signal with quasi-orthogonal codes, a second spreader for spreading another input signal with Walsh codes, and a PN (Pseudo-Noise) spreader for complex-spreading output signals of the first and second spreaders with PN sequences. The quasi-orthogonal codes are characterized in that a partial correlation value with the Walsh codes does not exceed a lowest partial correlation limit value.
摘要:
A code set generating method in a mobile communications system having Nf frequency channels and Np phase channels. In the method, a code length Nc is obtained by Nf×Np, a minimum distance Nd between codewords in a code set and frequency diversity Nfd are determined, code sets are detected according to Nc, Nd, and Nfd, a code set is selected, which shows such a Hamming distance distribution among code words that minimizes demodulation errors from the detected code sets, and the code set is stored in a mapping table of a demodulator.
摘要:
A device and method for generating a pseudo-orthogonal code for use in orthogonally spreading channel data in a CDMA mobile communications system. M orthogonal codes are selected from N orthogonal codes, for forming a pseudo-orthogonal codes, and the elements of the selected M orthogonal codes are sequentially interlaced to generate the pseudo-orthogonal code as a sequence of M×N elements.
摘要:
There are provided spread spectrum signal generating devices and methods in a transmitter of a mobile communications system using a plurality of logical channels. In the spread spectrum signal generating devices, a multiplexer time multiplexes a pilot channel signal and a control channel signal which are output at substantially constant power levels. A first orthogonal encoder orthogonally spreads the output of the multiplexer with an orthogonal code. A second orthogonal encoder orthogonally spreads voice channel data of a variable bit rate with an orthogonal code. A third orthogonal encoder orthogonally spreads packet channel data of a variable bit rate with an orthogonal code. An IQ signal mapper adds the outputs of the first and third orthogonal encoders, outputs the added signal as a first channel signal, and outputs the output of the second orthogonal encoder as a second channel signal. A PN spreader spreads the first and second channel signals with PN codes and outputs a final spectrum spread signal, which exhibits a substantially minimized peak-to-average power ratio.
摘要:
A device and method for performing channel encoding using a frame structure having a termination effect in a recursive systemic encoder for a communication system. The channel encoding device having: an inserter for inserting at least one predefined bit in an input data bit stream at a predetermined position; and a channel encoder for encoding the bit-inserted data bit stream.
摘要:
A device and method for generating and distributing convolutional codes such that performance degradation due to a bad link environment may be minimized during channel decoding in a CDMA communication system. The convolutional encoder encodes transmission data at a coding rate of R=1/6 and can be used for a channel encoder. Such a channel encoder can be used in both a DS-CDMA communication system and a multicarrier CDMA communication system. When the channel encoder is used in the multicarrier CDMA communication system, the symbols outputted from multiple constituent encoders for the channel encoder are distributed to multiple carrier channels according to a predetermined rule, and the constituent encoders for the channel encoder can minimize the performance degradation of the overall channel encoder even though an output of a particular constituent encoder is completely off at the transmission channel.
摘要:
A communication device for a direct sequence code division multiple access (DS-CDMA) communication system is disclosed. The communication device comprises a CRC (Cyclic Redundancy Code) generator for generating CRC bits according to input data bits and adding the generated CRC bits to the input data bits; a channel encoder for encoding the CRC-added data bits using a coding rate R=1/6 convolutional code of a generator polynomial of (457, 755, 551, 637, 625, 727); and an interleaver for interleaving the coded data bits.
摘要:
A channel decoding device for a receiver which receives symbols coded by inserting at least one specific bit in a data frame at a predetermined position. In the channel decoding device, a symbol inserter receives the symbols, inserts a symbol having a specific value at a predetermined specific bit insert position and outputs the received symbols at other positions. A decoder decodes symbols output from the symbol inserter.
摘要:
A method for a decoding device to decode a codeword matrix of a product code includes: generating a first extended parity check matrix for a vertical code; decoding a horizontal codeword of a plurality of rows in the codeword matrix to thus perform a first decoding process; generating a second extended parity check matrix by removing a column corresponding to a row of the first decoding-succeeded horizontal codeword from the first extended parity check matrix; and decoding the first decoding-failed horizontal codeword by using the second extended parity check matrix to thus perform a second decoding process. Therefore, the simple and reliable product code decoding method is provided.
摘要:
The present invention relates to a source antenna switching scheme for a non-orthogonal protocol; and more particularly, to a source antenna switching scheme for a non-orthogonal protocol, which transmits a signal of a source node to a destination node through a relay node. The present invention provides a source antenna switching scheme for a non-orthogonal decode-and-forward protocol that can acquire a greater diversity than the conventional NDF protocol. In other words, the present invention provides a source antenna switching scheme for a non-orthogonal decode-and-forward protocol that can increase a diversity order by adding a reasonable priced antenna instead of expensive hardware such as an RF chain when there are a plurality of antenna in the RF chain.