Modulators – Phase shift keying modulator or quadrature amplitude modulator – Including logic element
Patent
1992-11-04
1994-11-29
Mis, David
Modulators
Phase shift keying modulator or quadrature amplitude modulator
Including logic element
375 56, 375 57, 375 67, H03C 300, H04L 2710, H04L 2720
Patent
active
053693787
ABSTRACT:
A digital DQPSK modulator according to the present: invention limits respective bands of symbol mapping data of I phase and Q phase obtained by applying differential encoding and mapping processings to a digital baseband signal, and multiplies the obtained data by the carrier signals by means of the digital filter. Such limiting of the bands and multiplication by the carrier signals are carried out by the digital filter in a time-divisionally multiplexed manner. The digital filter includes a circuit, for accumulating symbol mapping data for each of the I phase and the Q phase corresponding to a plurality of symbol sections, a plurality of ROMs corresponding to the plurality of symbol sections for storing a multiplication result of symbol data corresponding to a predetermined filter waveform and the carrier signal, and an adder for adding data output from these ROMs. The adder outputs a digital modulated signal which is, in turn, converted into an analog modulated signal by a D/A converter.
REFERENCES:
patent: 4584540 (1986-04-01), DuBose et al.
patent: 5115468 (1992-05-01), Asahi et al.
patent: 5140613 (1992-08-01), Birgenheier et al.
patent: 5157693 (1992-10-01), Lemersal, Jr. et al.
patent: 5175514 (1992-12-01), Iinuma et al.
patent: 5177455 (1993-01-01), Bennett
patent: 5177769 (1993-01-01), Arnold et al.
patent: 5225795 (1993-07-01), Iinuma
Yongacoglu et al., "Differential Detection of GMSK Using Decision Feedback", IEEE Transactions on Communications, vol. 36, No. 6, Jun. 1988, pp. 641-649.
Murota et al., "GMSK Modulation for Digital Mobile Telephony", IEEE Transactions on Communications, vol. com-29, No. 7, Jul. 1981, pp. 1044-1050.
Hama Mitsuji
Iinuma Toshinori
Kosaka Akio
Yoshimoto Mitsufumi
Michaelson Peter L.
Mis David
Sanyo Electric Co,. Ltd.
Tottori Sanyo Electric Co. Ltd.
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