US 2002/0176486 A1Published application

Spread spectrum transmission apparatus, spread spectrum reception apparatus, and spread spectrum communication system

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorsSeiji Okubo, Tatsuya Uchiki, Toshiharu Kojima

Life of this patent

Estimating the term…

Loading patent…

Abstract

A spread spectrum transmission apparatus includes, a chip clock generation section which outputs a chip clock in one frame formed of M+L−1 chips, a frame clock generation section which outputs a frame clock synchronized to frame occurrence timing, SS-PPM signal generation sections each of which inserts a pseudonoise code sequence corresponding to one period from some of M chips located at a head of a frame based on K-bit transmission data and generates an SS-PPM signal, delay sections which respectively delay N SS-PPM signals respectively by determined delay quantities, and a multiplexing section which adds up all of outputs respectively of the delay units and generates a multiplexed SS-PPM signal.

Claims10

Dependent claims

A spread spectrum transmission apparatus comprising:

a chip clock generation unit which outputs a chip clock having a clock rate corresponding to a chip rate in one frame formed of M+L−1 chips, the M+L−1 being determined by a pseudonoise code sequence having a period of L chips and M chips which represents a number of pulse position information pieces corresponding to an information content to be transmitted,
a frame clock generation unit which conducts frequency division on the chip clock output by the chip clock generation unit by a factor of M+L−1, and outputs a frame clock synchronized to frame occurrence timing;
N (where N is an integer of 2 or greater) spread spectrum pulse position modulated signal generation units each of which inserts the pseudonoise code sequence corresponding to one period from some of the M chips located at a head of a frame based on K-bit (where K is an integer of 2 or greater) transmission data by taking a rising edge of the frame clock output by the frame clock generation unit as a reference, and generates a spread spectrum pulse position modulated signal;
N delay units which delay outputs respectively of the N spread spectrum pulse position modulated signal generation units by determined delay quantities {τ1Tc, τ2Tc, τ3Tc, . . . , τNτc} (where delay factors {τ1, τ2, τ3, . . . , τN} are integers which satisfy 0≦τ1, τ2, τ3, . . . , τN<L, and Tc is a chip period);
and
a multiplexing unit which adds up all of outputs respectively of the N delay units, and generates a multiplexed spread spectrum pulse position modulated signal.

3 more elements

A spread spectrum communication system comprising:

a spread spectrum transmission apparatus comprising;
a chip clock generation unit which outputs a chip clock having a clock rate corresponding to a chip rate in one frame formed of M+L−1 chips, theM+L−1 being determined by a pseudonoise code sequence having a period of L chips and M chips which represents a number of pulse position information pieces corresponding to an information content to be transmitted,
a frame clock generation unit which conducts frequency division on the chip clock output by the chip clock generation unit by a factor of M+L−1, and outputs a frame clock synchronized to frame occurrence timing,
N (where N is an integer of 2 or greater) spread spectrum pulse position modulated signal generation units each of which inserts the pseudonoise code sequence corresponding to one period from some of the M chips located at a head of a frame based on K-bit (where K is an integer of 2 or greater) transmission data by taking a rising edge of the frame clock output by the frame clock generation unit as a reference, and generates a spread spectrum pulse position modulated signal,
N delay units which delay outputs respectively of the N spread spectrum pulse position modulated signal generation units by determined delay quantities {τ1Tc, τ2Tc, τ3Tc, . . . , τNTc} (where delay factors {τ1, τ2, τ3, . . . , τN} are integers which satisfy 0≦τ1, τ2, τ3, . . . , τN<L, and Tc is a chip period), and
a multiplexing unit which adds up all of outputs respectively of the N delay units, and generates a multiplexed spread spectrum pulse position modulated signal which conducts delay processing on a frame formed of M+L−1 chips, multiplexes N (where N is an integer of 2 or greater) spread spectrum pulse position modulated signals, and transmits a resultant multiplexed signal, the M+L−1 being determined by a pseudonoise code sequence having a period of L chips and M chips which represents a number of pulse position information pieces corresponding to an information content to be transmitted;
and
a spread spectrum reception apparatus comprising;
a matched filter which conducts correlation computation between a received signal and a pseudonoise code sequence and outputs a result of the computation as a correlation signal, one frame of the received signal being formed of M+L−1 chips determined by the pseudonoise code sequence having a period of L chips and M chips which represents a number of pulse position information pieces corresponding to an information content to be transmitted,
a frame synchronization unit which outputs a reproduced frame clock synchronized to start timing of the frame based on the correlation signal,
N (where N is an integer of 2 or greater) delay correction units which conduct delay correction so as to align start timing of the frames with respect to the correlation signal output by said matched filter, and
N pulse position demodulation units which conduct pulse position demodulation by using N delay-corrected correlation signals output respectively by the N delay correction units and the reproduced frame clock, and output parallel demodulated data sequences each having K bits which conducts delay correction processing on the multiplexed spread spectrum pulse position modulated signals received by using a pseudonoise code sequence identical to the pseudonoise code sequence used in said spread spectrum transmission apparatus, and conducts demodulation processing.

9 more elements

A spread spectrum communication system comprising:

a spread spectrum transmission apparatus comprising;
a chip clock generation unit which outputs a chip clock having a clock rate corresponding to a chip rate in one frame formed of M+L−1 chips, the M+L−1 being determined by a pseudonoise code sequence having a period of L chips and M chips which represents a number of pulse position information pieces corresponding to an information content to be transmitted,
a frame clock generation unit which conducts frequency division on the chip clock output by the chip clock generation unit with a factor of M+L−1, and outputs a frame clock synchronized to frame occurrence timing,
N (where N is an integer of 2 or greater) spread spectrum pulse position modulated signal generation units each of which inserts the pseudonoise code sequence corresponding to one period from some of the M chips located at a head of a frame based on K-bit (where K is an integer of 2 or greater) transmission data by taking a rising edge of the frame clock output by the frame clock generation unit as a reference, and generates a spread spectrum pulse position modulated signal,
N delay units which delay outputs respectively of the N spread spectrum pulse position modulated signal generation units by determined delay quantities {τ1Tc, τ2Tc, τ3Tc, . . . , τNTc} (where delay factors {τ1, τ2, τ3, . . . , τN} are integers which satisfy 0≦τ1, τ2, τ3, . . . , τN<L, and Tc is a chip period), and
a multiplexing unit which adds up all of outputs respectively of the N delay units, and generates a multiplexed spread spectrum pulse position modulated signal comprising, N phase shift units which respectively shift output phases respectively of the N delay units respectively by determined phase shift quantities and output the phase-shifted signals to the multiplexing unit which conducts delay processing and phase shift processing on a frame formed of M+L−1 chips, multiplexes N (where N is an integer of 2 or greater) spread spectrum pulse position modulated signals, and transmits a resultant multiplexed signal, the M+L−1 being determined by a pseudonoise code sequence having a period of L chips and M chips which represents a number of pulse position information pieces corresponding to an information content to be transmitted;
and
a spread spectrum reception apparatus comprising;
a matched filter which conducts correlation computation between a received signal and a pseudonoise code sequence and outputs a result of the computation as a correlation signal, one frame of the received signal being formed of M+L−1 chips determined by the pseudonoise code sequence having a period of L chips and M chips which represents a number of pulse position information pieces corresponding to an information content to be transmitted;
a frame synchronization unit which outputs a reproduced frame clock synchronized to start timing of the frame based on the correlation signal,
N (where N is an integer of 2 or greater) delay correction units which conduct delay correction so as to align start timing of the frames with respect to the correlation signal output by said matched filter, and
N pulse position demodulation units which conduct pulse position demodulation by using N delay-corrected correlation signals output respectively by the N delay correction units and the reproduced frame clock, and output parallel demodulated data sequences each having K bits;
comprising;
N phase correction units which are provided on an input side of the N delay correction units, and which conduct phase correction so as to align carrier phases of correlation signals output by said matched filter, and output resultant signals to the N delay correction units, or
N phase correction units which are provided on an output side of the N delay correction units, and which conduct phase correction so as to align carrier phases of correlation signals aligned with frame start timing by the N delay correction units, and output resultant signals to the Npulse position demodulation units which conducts delay correction processing and phase correction processing on the multiplexed spread spectrum pulse position modulated signals received by using a pseudonoise code sequence identical to the pseudonoise code sequence used in said spread spectrum transmission apparatus, and conducts demodulation processing.

12 more elements

Dependencies are inferred from the claim text.