Mobile telephone station with power saving circuit

• US 5,031,231 A
• Filed: 09/26/1989
• Issued: 07/09/1991
• Est. Priority Date: 09/26/1988
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Miyazaki, Shinichi
• Primary Examiner(s): KUNTZ, CURTIS A
• Application Number:
  US07/412,378
• Time in Patent Office: 651 Days
• Field of Search: 455/127, 455/343, 455/54, 455/89, 455/76, 379/58-60, 379/63
• US Class Current: 455/574
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile station comprises a receiver for receiving a signal from the base station and a transmitter including a frequency synthesizer, a modulator and a power amplifier connected to it. For power savings purposes, the transmitter is deactivated during a standby mode. If an earlier portion of a signal received from the base station indicates a likelihood of a need to return an acknowledgment, power is supplied to the frequency synthesizer to allow it to stabilize in advance. If a later portion of the received signal indicates that there actually exists the need to acknowledge the receipt of the signal, the power amplifier is subsequently activated and an acknowledgment signal is returned through it to the base station. If the later portion of the received signal indeicates the absence of the need to acknowledge, the frequency synthesizer is again deactivated and the power amplifier remains deactivated.

Claims

1. A mobile station for exchanging signals with a base station which requests an acknowledgment to be returned from the mobile station within a specified period of time from reception of a signal from the base station, comprising:

receiver means for receiving a signal from said base station;

transmitter means for transmitting signals to said base station; and

control means coupled to said transmitter means for deactivating said transmitter means during a standby mode of said mobile station to save power consumption, said control means being further coupled to said receiver means for determining from an earlier portion of a signal received by said receiver means that there is a likelihood of a need to return said acknowledgement and supplying power to said transmitter means in advance and determining from a later portion of said received signal whether said need actually exists or not, and causing said transmitter means to transmit said acknowledgment if the determination from the later portion indicates the presence of said need or deactivating said transmitter means again if the determination from the later portion indicates the absence of said need.

2. A mobile station as claimed in claim 1, wherein said transmitter means comprises frequency synthesizer means for generating a carrier, means for modulating a signal to be transmitted to said base station upon said carrier, and a power amplifier for amplifying the modulated carrier for transmission to said base station, said frequency synthesizer means having a longer warm-up time than said specified period to stabilize the frequency of said carrier, wherein said control means supplies power to said frequency synthesizer means when the determination from said earlier portion indicates the presence of said likelihood, and supplies power to said power amplifier if the determination from said later portion indicates the presence of said need and deactivating said frequency synthesizer means if the determination from said later portion indicates the absence of said need.

3. A mobile station as claimed in claim 2, wherein said earlier and later portions of said received signal are earlier and last digits, respectively, of a subscriber identification number assigned to said mobile station.

4. A mobile station as claimed 2, wherein said control means supplies power to the power amplifier so that the power amplifier is activated sufficiently for amplification at a point in time substantially coincident with the time at which the carrier generated by said frequency synthesizer means is stabilized.