JPH04213930A - Portable telephone set - Google Patents

Abstract

PURPOSE:To reduce power consumption of the portable telephone set by employing a detection circuit and a control circuit for a slave set. CONSTITUTION:A slave set is provided with a detection circuit 151 detecting a reception level of a transmission signal Sd of an outgoing channel and a circuit 140 controlling a transmission output of a transmission signal Su of an incoming channel. According to a detection signal Ss of the detection circuit 151, the transmission output of a transmission circuit 110 is controlled so as to minimize the output of the transmission signal Su of the incoming channel.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile phone.

0002

2. Description of the Related Art Car telephones are becoming popular as wireless telephone systems. In this wireless telephone system, a handset can move from one base station's service area (base station area) to another base station's service area while making a call. Alternatively, calls can be made and received from a car moving at high speed.

[0003] However, in order to realize such a function, the base station must always manage or know the current location of each slave unit. For this reason, the base stations must be connected to each other by computers, making the base station system complex and large-scale.

[0004] In contrast to such radio telephone systems, there is a mobile telephone system called a telepoint system as a next generation radio telephone system. Depending on the country, this may be PHP (Japan), CT-2 (Europe), or D
It is also called ECT (USA).

[0005] In this telepoint system, the base station (telepoint base station) does not, in principle, manage slave units. Therefore, although it is possible to make calls from the handset, calls cannot be received to the handset. When an incoming call is required, the handset notifies the base station of the current location in advance by performing a predetermined key operation.

[0006] Furthermore, since the base station does not manage the handset, the handset cannot move from the service area of one base station to the service area of another base station while talking. You can only move within one service area.

In other words, the telepoint system is similar to a wireless public telephone or a cordless telephone that can be carried over a wide range.

[0008] In the telepoint system, although there are restrictions on the use of slave units, the base station does not have to manage the slave units in principle, so the base station can be significantly simplified.

[0009]

[Problem to be solved by the invention] However, although cordless handsets are portable and are used not only indoors but also in cities,
In such cases, it may not be possible to easily charge the battery. Therefore, the power consumption of the handset becomes a problem.

In particular, in the telepoint system,
Since the used frequency band is a quasi-microwave band of 1 to 3 GHz such as 1.8 GHz and 2.6 GHz, it requires more power for transmission, and power consumption becomes a very big problem.

[0011] Moreover, as the handset becomes smaller, the battery also becomes smaller, and the capacity of the battery becomes smaller.

[0012] The present invention aims to solve these problems.

[0013]

[Means for Solving the Problems] Therefore, in the present invention, when the reference numerals of each part correspond to the embodiments described later, there is provided a transmitter 111 and an audio signal S from the transmitter 111.
a transmission circuit 110 that converts t into an uplink channel transmission signal Su and transmits the uplink channel modulation signal Sd;
a receiving circuit 120 that receives the audio signal Sr and extracts the audio signal Sr; and the audio signal Sr extracted by the receiving circuit 120.
, a detection circuit 151 that detects the reception level of the down-channel modulated signal Sd received by the reception circuit 120, and a circuit that controls the transmission output of the transmission circuit 110 based on the detection output Ss of this detection circuit 151. 140 is provided.

Then, the detection output Ss of the detection circuit 151
Therefore, when the receiving level of the receiving circuit 120 is high, the transmitting output of the transmitting circuit 110 is controlled to be small, and when the receiving level is low, the transmitting output is controlled to be large.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example in which the present invention is applied to a slave unit of a telepoint system. First, the basic configuration and operation of the slave unit will be explained.

In FIG. 1, 110 is a transmitting circuit, 120
is a receiving circuit, and the transmitting circuit 110 receives the audio signal St
The receiving circuit 120 receives the down channel FM signal Sd from the base station and demodulates the audio signal Sr etc. .

Furthermore, 131 is a dial key, 132 is an operation key such as a talk key, 133 is a key interface, and 140 is a microcomputer for system control. In this microcomputer 140, 141 is a CPU, 142 is a ROM in which various programs are written, 143 is a RAM for a work area, and these memories 142 and 143 are connected to the CPU 141 through a system bus 149.

During a call, the audio signal St from the transmitter 111 is supplied to the FM modulation circuit 113 through the amplifier 112, where it is converted into an FM signal Su, and this signal Su is supplied to the frequency converter 114. An oscillation signal of a predetermined frequency is supplied from the oscillation circuit 101 to the converter 114, and the frequency of the FM signal Su is converted into an FM signal Su of a predetermined upstream channel. Then, this FM signal Su is transmitted to the bandpass filter 115.
→ Transmission power amplifier 116 → Duplexer 117 signal line is supplied to the antenna 100, and the base station (
(not shown).

[0019] Also, the FM of the downlink channel from the base station
A signal Sd is received by the antenna 100, and this signal Sd is transmitted from the duplexer 117 to the high frequency amplifier 121 to
It is supplied to the frequency converter 123 through the signal line of the bandpass filter 122, and the oscillation circuit 10
The oscillation signal from FM 1 is supplied to converter 123 and
The signal Sd is converted into an intermediate frequency signal Si. Then, this signal Si passes through the intermediate frequency amplifier 124 to F
The voice signal S of the other party is supplied to the M demodulation circuit 125.
r is demodulated and this signal Sr is supplied to the receiver 127 through the amplifier 126.

[0020] Therefore, the handset can communicate with the other party through the base station. Note that at this time, the oscillation frequency of the oscillation circuit 101 is controlled by the CPU 141 through the interface 102, and the channel between the slave unit and the base station is set to a predetermined channel.

[0021] In particular, the present invention is constructed as follows.

That is, an intermediate frequency signal Si is taken out from the intermediate frequency amplifier 124, this signal Si is supplied to the detection circuit 151, a signal Ss indicating the reception level of the FM signal Sd is taken out, and this signal Ss is sent to the A/D. The signal is A/D converted by converter 152 and then supplied to interface 153, which is connected to bus 149.

Furthermore, the output level of the transmitting power amplifier 116 is made variable by, for example, controlling its power supply voltage. Further, an interface 154 is connected to the bus 149, and the output from the interface 154 is D/A converted by a D/A converter 155 and then supplied to the amplifier 116 as a control signal CTRL.

During a call, the detection circuit 151 detects the reception level of the downlink FM signal Sd, and this detection signal Ss is sent to the CPU 141 at a predetermined period through the interface 153.
It is checked whether the reception level of the FM signal Sd at that time is equal to or higher than the level Vth required to maintain a predetermined speech quality.

As a result of this check, the FM signal S
When the reception level of d is equal to or higher than level Vth, CP
A control signal CTRL is supplied from U141 to amplifier 116 through interface 154 and D/A converter 155, and the output level of FM signal Su from amplifier 116 is decreased by one step.

Further, as a result of the check, if the reception level of the FM signal Sd is lower than the level Vth, the CPU 14
FM from amplifier 116 by control signal CTRL from 1
The output level of the signal Su is increased by one step.

[0027] Since such operations are repeated at predetermined intervals, the transmission output of the handset is controlled to be at or close to the level required to maintain the required speech quality.

[0028] Therefore, the transmission output of the amplifier 116 is controlled to the required minimum value, and the transmission output does not become larger than necessary, so that the consumption of a battery (not shown) can be suppressed to a minimum.

[0029] When making a call, the output of the amplifier 116 is set to the maximum in order to ensure that the command signal is transmitted from the handset to the base station until the call is ready, and the transmission output of the FM signal Su is is assumed to be the maximum.

Furthermore, although the above description deals with the case of a handset of a telepoint system, the present invention can also be applied to a handset of a cordless telephone.

[0031]

[Effects of the Invention] Thus, according to the present invention, the transmission output of the handset is controlled to the minimum value necessary to maintain call quality, so power consumption is reduced, and the length of time that a call can be made with one charge is reduced. becomes longer.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an example of the present invention.

[Explanation of symbols]

110 Transmission circuit 111 Transmitter 113 Modulation circuit 116 Transmission power amplifier 120 Receiving circuit 124 Intermediate frequency amplifier 125 Demodulation circuit 127　Telephone receiver 140 Microcomputer 151 Detection circuit 152 A/D converter 155 D/A converter

Claims (1)

[Claims] [Claim 1] A transmitter, a transmitter circuit that converts an audio signal from the transmitter into an uplink channel transmission signal, and a receiver circuit that receives a downlink modulated signal and extracts the audio signal. , a receiver to which the audio signal extracted by the receiving circuit is supplied, a detection circuit for detecting the reception level of the modulated signal of the down channel received by the receiving circuit, and a detection output of the detection circuit to detect the transmission of the transmitting circuit. and a circuit for controlling an output, according to the detection output of the detection circuit, when the reception level of the reception circuit is high, the transmission output of the transmission circuit is small, and when the reception level is small, the transmission output of the transmission circuit is small. A mobile phone whose transmission output is controlled to increase.