Title:
DIGITAL RADIO MODULATOR
Document Type and Number:
Japanese Patent JP3169714
Kind Code:
B2
Abstract:
PURPOSE: To perform control in response to an error signal by providing a digital carrier phase generator, an arithmetic logic unit, a look-up table which generates a trigonometrical digital output, and a D/A converter which converts its output.
CONSTITUTION: A frequency offset phase generator 1 makes a calculation on the basis of an error in a local oscillator and the actual frequency of an antenna and stores the result in a frequency offset phase register 10. The output of a carrier phase generator 2 and the output of the generator 1 are combined by the arithmetic logic unit ALU 3. A modulation phase generator 4 calculates a phase of modulation according to digital data applied to 4a and generates 16 phase values by symbols. An ALU 5 combines the outputs of the ALU 3 and generator 4 and outputs the result to a cosine look-up table LUT 7. The LUT 7 converts a 12-bit phase into an 8-bit number and applies to a multiplier 14, which generates a signal having both its amplitude and phase modulated at the same time, so that the signal is outputted through a D/A converter 8 and a BPF 9.
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Inventors:
David breaker
Application Number:
JP31758092A
Publication Date:
May 28, 2001
Filing Date:
November 27, 1992
Export Citation:
Assignee:
Nokia Mobile Phones (U.K.) Limited
International Classes:
H03M1/66; H04B7/24; H04L27/12; H04L27/14; H04L27/18; H04L27/20; (IPC1-7): H04L27/12; H04B7/24; H04L27/14
Domestic Patent References:
| JP5881364A | ||||
| JP55147060A | ||||
| JP62165454A | ||||
| JP583306A | ||||
| JP61261947A | ||||
| JP3105053U |
Other References:
【文献】米国特許4584541(US,A)
Attorney, Agent or Firm:
Minoru Nakamura (6 outside)