Title:
CORRELATION DETECTOR AND COMMUNICATION APPARATUS
Document Type and Number:
WIPO Patent Application WO/1995/010903
Kind Code:
A1
Abstract:
A correlation detector for CDMA communication receivers, which can establish synchronization at a high speed, can extract mutually correlated components, and can perform highly accurate tracking. The received signal (21) is fed to a matched filter (43) when the initial synchronization is established. When a synchronization judging circuit (45) judges that the filter (43) detects synchronization, the switching circuit (42) feeds the signal (21) to multipliers (47, 48), and resets a VCCG (29) and a spread-spectrum code replica generator (30). After the synchronization is established, the spread-spectrum signal is detected quasi-synchronously, the received signal quasi-synchronously detected is multiplied by replical codes having advanced and lagged phases, and correlation detection signals are extracted from the multiplication results. The square components are generated, added together in opposite phases, and averaged in the time direction. The received spread-spectrum signal is multiplied by the codes whose phases are synchronous, and the results are integrated over chips. The signal, after the averaging processing, is reversely modulated by use of the identification signal of the received data obtained by compensation for the phase error of the received signal in order to generate a phase error signal. The replica code generator is driven by a clock the phase of which is controlled by the phase error signal.
Inventors:
DOHI TOMOHIRO (JP)
SAWAHASHI MAMORU (JP)
ADACHI FUMIYUKI (JP)
SAWAHASHI MAMORU (JP)
ADACHI FUMIYUKI (JP)
Application Number:
PCT/JP1994/001715
Publication Date:
April 20, 1995
Filing Date:
October 13, 1994
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE (JP)
DOHI TOMOHIRO (JP)
SAWAHASHI MAMORU (JP)
ADACHI FUMIYUKI (JP)
DOHI TOMOHIRO (JP)
SAWAHASHI MAMORU (JP)
ADACHI FUMIYUKI (JP)
International Classes:
H04B1/707; H04B7/212; H04L7/00; (IPC1-7): H04L7/00; H04J13/04; H04B7/216
Other References:
RICHARD A. YOST & ROBERT W. BOYD, "A Modified PN Code Tracking Loop: Its Performance Analysis and Comparative Evaluation", IEEE, Transactions on Communications, Vol. COM-30, No. 5, May 1982, left column, page 1027 to left column, page 1028, Figs. 1(a), 2.
MASAO NAKAGAWA, "Basic and Application of Spread Spectrum Communication Technology", Torikeps K.K., March 13, 1987, lines 27 to 32, page 77, lines 1 to 6, page 78, Figs. 10, 12.
KAZUMASA NITTA and two others, "Method of Constituting UW Reverse Modulation AFC and Characteristics", 1993 IEICE Autumn General Conference Lecture Theses, Vol. 2, Thesis No. B330, pages 2 to 330, September 5, 1993, lines 12 to 25, (1) Premodulation UW Detection Circuit, Fig. 1.
MASAO NAKAGAWA, "Basic and Application of Spread Spectrum Communication Technology", Torikeps K.K., March 13, 1987, lines 1 to 17, page 92, Fig. 28.
MASAO NAKAGAWA, "Basic and Application of Spread Spectrum Communication Technology", Torikeps K.K., March 13, 1987, lines 27 to 32, page 77, lines 1 to 6, page 78, Figs. 10, 12.
KAZUMASA NITTA and two others, "Method of Constituting UW Reverse Modulation AFC and Characteristics", 1993 IEICE Autumn General Conference Lecture Theses, Vol. 2, Thesis No. B330, pages 2 to 330, September 5, 1993, lines 12 to 25, (1) Premodulation UW Detection Circuit, Fig. 1.
MASAO NAKAGAWA, "Basic and Application of Spread Spectrum Communication Technology", Torikeps K.K., March 13, 1987, lines 1 to 17, page 92, Fig. 28.
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