Telecommunications – Transmitter – With feedback of modulated output signal
Patent
1998-11-16
2000-07-18
Mullen, Thomas
Telecommunications
Transmitter
With feedback of modulated output signal
330149, 375297, H04B 104
Patent
active
060919418
ABSTRACT:
Disclosed is a radio apparatus in which modulating signals (I, Q signals) from an arithmetic/control unit are converted to analog signals, which are then applied to an orthogonal modulator. A modulated wave for transmission, which has been produced by orthogonally modulating a reference carrier wave by the modulating signals, is demodulated by the orthogonal detector. The arithmetic/control unit compares the modulating signals and the demodulated signals and, based upon the comparison, updates distortion compensation coefficients and applies pre-distortion processing to the modulating signal using the distortion compensation coefficients. Leakage carrier produced due to offset of the orthogonal modulator is detected and the arithmetic/control unit adjusts the level of the modulating signals or shifts the phase of the reference carrier wave in such a manner that the leakage carrier (offset) becomes zero.
REFERENCES:
patent: 4700151 (1987-10-01), Nagata
patent: 4890056 (1989-12-01), Peters et al.
patent: 4939791 (1990-07-01), Bochmann et al.
patent: 4985688 (1991-01-01), Nagata
patent: 5091919 (1992-02-01), Kuisma
patent: 5148448 (1992-09-01), Karam
patent: 5191597 (1993-03-01), Ekelund et al.
patent: 5396190 (1995-03-01), Murata
patent: 5404579 (1995-04-01), Obayashi et al.
patent: 5452473 (1995-09-01), Weiland et al.
patent: 5870668 (1999-02-01), Takano et al.
Kabashima Masaru
Kaneko Yuji
Moriyama Yukihiro
Takata Koji
Fujitsu Limited
Mullen Thomas
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