Telecommunications – Receiver or analog modulated signal frequency converter – Plural receivers
Patent
1979-05-03
1983-08-02
Chin, Tommy P.
Telecommunications
Receiver or analog modulated signal frequency converter
Plural receivers
455141, 357 40, H04B 706
Patent
active
043970362
ABSTRACT:
A diversity system utilizing a plurality of branches has been found for an angle modulated digital signal transmission. The received signal on each branch is modulated with a local signal which has the same period as the digital signal, and satisfies the orthogonal relationship with each other. The modulated signals are combined by simply summing them, and the combined signal is differentially detected. In the case of two branches, said orthogonal local signals are .sqroot.2/T.multidot. sin (2.pi./T)t, and .sqroot.2/T.multidot. cos (2.pi./T)t, where T is the bit duration of the digital signal, and said local modulation is the amplitude modulation. The present invention can provide the same diversity effect as the prior maximal ratio combining system, although the present invention does not utilize a complicated cophasing means between each branches.
REFERENCES:
patent: 2955199 (1960-10-01), Mindes
patent: 3339199 (1967-08-01), Pichafroy
patent: 3348152 (1967-10-01), Laughlin, Jr.
patent: 3462554 (1969-10-01), Steel, Jr.
patent: 3663107 (1972-01-01), 455
patent: 3755739 (1973-08-01), Okano
patent: 4027247 (1977-05-01), Aranguren
patent: 4142155 (1979-02-01), Adachi
A Periodic Switching Diversity Technique for a Digital FM Land Mobil Radio, By F. Adachi, et al., IEEE Transactions on Vehiclar Technology, vol. VT 27, No. 4, Nov. 1978, pp. 211-219.
Adachi Fumiyuki
Hattori Takeshi
Hirade Kenkichi
Chin Tommy P.
Nippon Telegraph and Telephone Public Corporation
LandOfFree
Diversity system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Diversity system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diversity system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-487739