Cellular telephone

• US 6,408,193 B1
• Filed: 11/09/1999
• Issued: 06/18/2002
• Est. Priority Date: 11/10/1998
• Status: Expired due to Term

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Katagishi, Makoto, Machida, Shirou
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Ferguson, Keith
• Application Number:
  US09/436,502
• Time in Patent Office: 952 Days
• Field of Search: 455/571, 455/126, 455/127, 455/115, 455/116, 455/118, 455/121, 455/125, 455/73, 455/232.1, 455/132.4, 455/239.1, 455/240.1, 455/250.1, 455/251.1, 455/245.1, 455/574, 330/278, 330/285, 330/129, 330/2, 375/345, 370/311, 370/342
• US Class Current: 455/571
• CPC Class Codes: H04B 1/52 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions

Abstract

A cellular telephone receives a first communication signal from a cell-site station and transmits a second communication signal to the cell-site station. The cellular telephone includes an antenna, a duplexer, a receiver, an encoder/decoder apparatus, an acoustic transducer, a transmitter and a controller. The receiver is connected to the antenna through the duplexer. The receiver converts the first communication signal into a voice signal code, and outputs a signal indicating an intensity of the first communication signal. The transmitter is connected to the encoder/decoder apparatus and to the antenna through the duplexer. The receiver converts the input voice code signal from the encoder/decoder apparatus into the second communication signal. The controller is connected to the receiver and the transmitter. The controller controls amplitude of the transmitter corresponding to said intensity of the first communication signal. The transmitter includes a variable amplitude amplifier and a power amplifier means, and the controller includes a central processing unit and a memory. The controller controls a gain of the variable amplitude amplifier and a bias condition of the power amplifier means according to a function stored in the memory.

Claims

1. A cellular telephone adapted to be used in a CDMA system, comprising:

an antenna for receiving a first communication signal and a transmitting power control signal from a cell-site station and transmitting a second communication signal to the cell-site station,

a duplexer connected to said antenna,

a receiver connected to said antenna through said duplexer for converting said first communication signal into a voice signal code, and for outputting a power control signal derived from said transmitting power control signal sent from said cell-site station,

an encoder/decoder apparatus connected to said receiver and an acoustic transducer for converting said voice signal code into an audio signal for driving said acoustic transducer and converting an audio input signal from said acoustic transducer into an input voice code signal,

a transmitter connected to said encoder/decoder apparatus and to said antenna through said duplexer for converting said input voice code signal into said second communication signal, and

a controller connected to said receiver and said transmitter for controlling an amplitude of said transmitter,

wherein said transmitter includes a variable amplitude amplifier and a power amplifier, said controller includes a central processing unit and a memory, said controller controls said transmitter so that an open-loop power control is performed and then a closed-loop power control is performed according to said power control signal so as to control the transmitted power to converge into a range required by said cell-site station, and said controller controls a gain of said variable amplitude amplifier and a bias condition of said power amplifier using a set of bias and gain data stored in said memory.

2. A cellular telephone according to claim 1, wherein said controller further includes a pulse generator, said pulse generator is connected to said power amplifier so as to supply a pulse as a bias control signal, and said controller controls a pulse width of said pulse so as to control said bias condition.

3. A cellular telephone according to claim 2, wherein said power amplifier further includes a smoothing circuit for smoothing said pulse.

4. A cellular telephone according to claim 1, wherein said controller further includes a pulse generator, said pulse generator is connected to said power amplifier so as to supply pulses as a bias control signal, and said controller controls a pulse density of said pulses so as to control said bias condition.

5. A cellular telephone according to claim 4 wherein said power amplifier further includes a smoothing circuit for smoothing said pulses.

6. A cellular telephone according to claim 1, wherein said transmitter further includes a signal generator connected to said controller, said signal generator is connected to said variable amplitude amplifier and said power amplifier so as to supply a gain control signal and a bias control signal to said variable amplitude amplifier and said power amplifier respectively.

7. A cellular telephone adapted to be used in a CDMA system, comprising:

an antenna for receiving a first communication signal and a transmitting power control signal from a cell-site station and transmitting a second communication signal to the cell-site station,

a duplexer connected to said antenna,

a receiver connected to said antenna through said duplexer for converting said first communication signal into a voice signal code, and for outputting a power control signal derived from said transmitting power control signal sent from said cell-site station,

an encoder/decoder apparatus connected to said receiver and an acoustic transducer for converting said voice signal code into an audio signal for driving said acoustic transducer and converting an audio input signal from said acoustic transducer into an input voice code signal,

a transmitter connected to said encoder/decoder apparatus and to said antenna through said duplexer for converting said input voice code signal into said second communication signal, and

a controller connected to said receiver and said transmitter for controlling an amplitude of said transmitter,

wherein said transmitter includes a variable amplitude amplifier and a power amplifier, said power amplifier includes a maximum power detector, said controller includes a central processing unit and a memory, said controller controls said transmitter so that an open-loop power control is performed and then a closed-loop power control is performed according to said power control signal so as to control the transmitted power to converge into a range required by said cell-site station, said controller controls a gain of said variable amplitude amplifier using a function defining a relation between bias data and gain data stored in said memory, and said maximum power detector controls and output power of said power amplifier.