Code division multiple access communication system and code division multiple access transmitting apparatus
AssigneeFujitsu Limited
InventorsTakaharu Nakamura, Kazuhisa Obuchi, Nobuhisa Aoki
Life of this patent
Estimating the term…
Abstract
In a CDMA transmitting apparatus, a cross-correlation value between different spreading-code sequences used to spread respective ones of a plurality of transmit signals is calculated, an interference interval of a spreading-code sequence is discriminated from the cross-correlation value calculated, and interference noise is reduced by halting transmission of at least one transmit signal, or partially altering at least one spreading-code sequence, with regard to all or part of a spreading-code sequence discriminated to be an interference interval.
Claims26
A spread signal transmitting apparatus in a code division multiple access communication system for spread-spectrum modulating a plurality of transmit signals using different spreading-code sequences, and simultaneously communicating a plurality of spread-spectrum modulated signals, comprising:
- a cross-correlation detector for calculating a cross-correlation value of spreading-code sequences each of which is assigned to each transmit signal;
- a discriminator for discriminating an interference interval of the spreading-code sequences from the cross-correlation value calculated;
- and
- a switch for halting transmission of at least one of said plurality of transmit signals with regard to all or part of a spreading-code sequence discriminated to be an interference interval.
A spread signal transmitting apparatus in a code division multiple access communication system for spread-spectrum modulating a plurality of transmit signals using different spreading-code sequences, and simultaneously communicating a plurality of spread-spectrum modulated signals, comprising:
- a cross-correlation detector for calculating, symbol by symbol, a cross-correlation value of spreading-code sequences each of which is assigned to each transmit signal;
- a discriminator for discriminating an interference interval of the spreading-code sequence from the cross-correlation value calculated;
- and
- a spreading-code altering unit for altering a code segment, which has been discriminated to be an interference interval, to another code with regard to at least one spreading-code sequence among said spreading-code sequences.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal transmitting apparatus has:
- an encoder for encoding each item of transmit data;
- a spread-spectrum modulator for modulating encoded data by different spreading-code sequences;
- a transmitter for transmitting each spread-spectrum modulated signal;
- a cross-correlation detector for calculating a cross-correlation value between said different spreading-code sequences;
- a discriminator for discriminating an interference interval of the spreading-code sequences from the cross-correlation value calculated;
- and
- a switch for halting transmission of at least one of said plurality of items of transmit data with regard to all or part of a spreading-code sequence discriminated to be an interference interval;
- and
- said spread signal receiving apparatus has:
- a despreading modulator for despreading receive data by a plurality of despreading-code sequences identical with spreading-code sequences;
- and
- a decoder for decoding transmit data from each despread signal.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal transmitting apparatus has:
- an encoder for encoding each item of transmit data;
- a spread-spectrum modulator for modulating encoded data by different spreading-code sequences;
- a transmitter for transmitting each spread-spectrum modulated signal;
- a cross-correlation detector for calculating, symbol by symbol, a cross-correlation value between said different spreading-code sequences;
- a discriminator for discriminating an interference interval of the spreading-code sequences from the cross-correlation value calculated;
- and
- a spreading-code altering unit for altering a code segment, which has been discriminated to be an interference interval, to another code with regard to at least one spreading-code sequence among said spreading-code sequences;
- and
- said spread signal receiving apparatus has:
- a despreading modulator for despreading receive data by a plurality of despreading-code sequences identical with spreading-code sequences;
- and
- a decoder for decoding transmit data from each despread signal.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal transmitting apparatus has:
- a cross-correlation detector for calculating a cross-correlation value of the spreading-code sequences each of which is assigned to each transmit signal;
- a discriminator for discriminating an interference interval of the spreading-code sequences from the cross-correlation value calculated;
- a spreading-code altering unit for altering a code segment, which corresponds to a spreading-code sequence that has been discriminated to be an interference interval, to another code with regard to at least one spreading-code sequence;
- and
- means for reporting altered condition of a spreading-code sequence to the spread signal receiving apparatus;
- and
- said spread signal receiving apparatus has a despreading-code altering unit which, based upon the altered condition of the spreading-code sequence reported, is for altering a despreading-code sequence in such a manner that it will become identical with said spreading-code sequence after the alteration.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal receiving apparatus has:
- a cross-correlation detector for calculating a cross-correlation value of code sequences that a transmitter uses for spread-spectrum modulation;
- a discriminator for discriminating an interference interval of the spreading-code sequences from the cross-correlation value calculated;
- and
- means for detecting position of a spreading-code sequence discriminated to be an interference interval, or position of code coincidence chip by chip within a spreading-code sequence discriminated to be an interference interval, and reporting this position to the transmitter;
- and
- said spread signal transmitting apparatus has:
- means for receiving position information sent from a receiver;
- and
- a switch for halting transmission of at least one transmit signal with regard to all or part of a prescribed spreading-code sequence based upon the position information reported.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal receiving apparatus has:
- a cross-correlation detector for calculating a cross-correlation value of code sequences that a transmitter uses for spread-spectrum modulation;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- means for detecting position of a spreading-code sequence discriminated to be an interference interval, or position of code coincidence chip by chip within a spreading-code sequence discriminated to be an interference interval, and reporting this position to the transmitter;
- and
- said spread signal transmitting apparatus has:
- means for receiving position information sent from a receiver;
- and
- a spreading-code altering unit for altering a code segment of a spreading-code sequence, which corresponds to said reported position information, to another code with regard to at least one spreading-code sequence.
A spread signal transmitting apparatus in a code division multiple access communication system for spread-spectrum modulating a plurality of transmit signals using different spreading-code sequences, and simultaneously communicating a plurality of spread-spectrum modulated signals, comprising:
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated transmit signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- a switch for halting transmission of at least one of said plurality of transmit signals with regard to all or part of a spreading-code sequence discriminated to be an interference interval.
A spread signal transmitting apparatus in a code division multiple access communication system for spread-spectrum modulating a plurality of transmit signals using different spreading-code sequences, and simultaneously communicating a plurality of spread-spectrum modulated signals, comprising:
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated transmit signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- a spreading-code altering unit for altering a code segment, which has been discriminated to be an interference interval, to another code with regard to at least one spreading-code sequence among said spreading-code sequences.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of transmit signals to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding a transmit signal from the despread signal, wherein said spread signal transmitting apparatus has:
- an encoder for encoding each item of transmit data;
- a spread-spectrum modulator for modulating encoded data by different spreading-code sequences;
- a transmitter for transmitting each spread-spectrum modulated signal;
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- a switch for halting transmission of at least one of said plurality of items of transmit data with regard to all or part of a spreading-code sequence discriminated to be an interference interval;
- and
- said spread signal receiving apparatus has:
- a despreading modulator for despreading receive data by a plurality of despreading-code sequences identical with spreading-code sequences;
- and
- a decoder for decoding transmit data from each despread signal.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal transmitting apparatus has:
- an encoder for encoding each item of transmit data;
- a spread-spectrum modulator for modulating encoded data by different spreading-code sequences;
- a transmitter for transmitting each spread-spectrum modulated signal;
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- a spreading-code altering unit for altering a code segment, which has been discriminated to be an interference interval, to another code with regard to at least one spreading-code sequence among said spreading-code sequences;
- and
- said spread signal receiving apparatus has:
- a despreading modulator for despreading receive data by a plurality of despreading-code sequences identical with spreading-code sequences;
- and
- a decoder for decoding transmit data from each despread signal.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal transmitting apparatus has:
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- a spreading-code altering unit for altering a code segment, which corresponds to a spreading-code sequence that has been discriminated to be an interference interval, to another code with regard to at least one spreading-code sequence;
- and
- means for reporting altered condition of a spreading-code sequence to the spread signal receiving apparatus;
- and
- said spread signal receiving apparatus has a despreading-code altering unit which, based upon the altered condition of the spreading-code sequence reported, is for altering a despreading-code sequence in such a manner that it will become identical with said spreading-code sequence after the alteration.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal receiving apparatus has:
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- means for detecting position of a spreading-code sequence discriminated to be an interference interval, or code coincidence position chip by chip within a spreading-code sequence discriminated to be an interference interval, and reporting this position to a transmitter;
- and
- said spread signal transmitting apparatus has:
- means for receiving position information sent from a receiver;
- and
- a switch for halting transmission of at least one transmit signal with regard to all or part of a prescribed spreading-code sequence based upon the position information reported.
A code division multiple access communication system having a spread signal transmitting apparatus for subjecting a plurality of items of transmit data to spread-spectrum modulation processing using mutually different spreading-code sequences and simultaneously transmitting a plurality of spread-spectrum signals obtained, and a spread signal receiving apparatus for despreading a receive signal by a despreading-code sequence identical with a spreading-code sequence and decoding transmit data from the despread signal, wherein said spread signal receiving apparatus has:
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- means for detecting position of a spreading-code sequence discriminated to be an interference interval, or code coincidence position chip by chip within a spreading-code sequence discriminated to be an interference interval, and reporting this position to a transmitter;
- and
- said spread signal transmitting apparatus has:
- means for receiving position information sent from a receiver;
- and
- a spreading-code altering unit for altering a code segment of a spreading-code sequence, which corresponds to said reported position information, to another code with regard to at least one spreading-code sequence.
A spread signal transmitting apparatus in a code division multiple access communication system for spread-spectrum modulating a plurality of transmit signals using different spreading-code sequences, and simultaneously communicating a plurality of spread-spectrum modulated signals, comprising:
- a cross-correlation detector for calculating a cross-correlation value of spreading-code sequences each of which is assigned to each transmit signal;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- a halting unit for halting transmission of at least one of said plurality of transmit signals with regard to all or part of a spreading-code sequence discriminated to be an interference interval.
A spread signal transmitting apparatus in a code division multiple access communication system for spread-spectrum modulating a plurality of transmit signals using different spreading-code sequences, and simultaneously communicating a plurality of spread-spectrum modulated signals, comprising:
- a cross-correlation detector for calculating a cross-correlation value between spread-spectrum modulated transmit signals;
- a discriminator for discriminating an interference interval of a spreading-code sequence from the cross-correlation value calculated;
- and
- a halting unit for halting transmission of at least one of said plurality of transmit signals with regard to all or part of a spreading-code sequence discriminated to be an interference interval.
Dependencies are inferred from the claim text.