JP3054474B2 - Transmission output control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital mobile communication device, and more particularly to an improvement for controlling a transmission output of a mobile station.

[0002]

2. Description of the Related Art In recent years, as communication media in the information network society, in addition to conventional wired telephones, in addition to automobile telephones, cordless telephones, pagers, and MCA.
(Multichannel access) Various media using wireless such as a system are being provided, and expectations for the early realization of a mobile phone in particular are increasing.

As means for controlling the transmission output of the own station in conventional mobile communication, the means shown in FIG. 3 is generally used. First, regarding the operation at the time of reception in FIG. 3, the reception switching signal 26 indicates that it is the timing of the reception slot of its own station among the time slots divided for time division multiplexing. While this signal is active, the antenna switching circuit 22 connects the antenna to the receiving side. At this time, the reception signal from the antenna 20 is transmitted to the high-frequency reception unit 2 via the antenna switching circuit 22.
1 and becomes a signal demodulated by the high-frequency receiving unit 21.

[0004] Next, regarding the operation at the time of transmission, the transmission switching signal 27 indicates that it is the timing of the transmission slot of its own station among the time slots divided for time division multiplexing. While this signal is active,
The antenna switching circuit 22 connects the antenna to the transmitting side. At this time, the transmission signal from the high-frequency transmission unit 25 is
Transmission output monitoring circuit 23, antenna switching circuit 22
Is transmitted from the antenna 20 via.

[0005] Regarding the transmission output control operation at the time of transmission, the transmission output to be transmitted from the high-frequency transmission unit 25 to the antenna 20 is monitored by a transmission output monitoring circuit 23 using a directional coupler or the like, and the level is detected. . The transmission output control circuit 24, to which this detection signal is input, controls the power gain or the bias circuit of the high-frequency transmission unit 25 according to this signal, so that the transmission output of the high-frequency transmission unit 25 of its own station is kept at a constant or arbitrary level. It is to become.

[0006]

However, according to the prior art, it is necessary to arrange a transmission output monitor circuit 23 such as a directional coupler between the high-frequency transmission unit 25 and the antenna 20, so that the transmission output monitor circuit 23 is required. However, there is a problem that an insertion loss occurs and transmission power is lost. Therefore, the output power setting of the high-frequency transmission unit 25 needs to be set with an added loss of the transmission output monitoring circuit 23, which is a cause of deterioration of the power efficiency of the transmission output.

Further, since a transmission output monitoring circuit using a directional coupler or the like is required, the circuit scale becomes large. In particular, the size of the directional coupler increases in inverse proportion to the transmission frequency. There is a problem that it becomes an obstacle to downsizing and downsizing of equipment.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a high-frequency transmitter, a high-frequency receiver, an antenna transmission / reception switching circuit, and transmission power control for detecting a signal level by time division multiplex communication. In the digital mobile radio communication device having a circuit, the transmission / reception switching circuit inputs a transmission output to a high-frequency receiving unit of the own station in an area other than the receiving slot of the own station during the time slot divided by time division multiplexing. The transmission power control circuit controls the transmission output by using the signal level of the transmission output of the own station detected by the high-frequency receiving unit.

[0009]

According to the above arrangement, the transmission / reception switching circuit transmits the transmission signal output from the high-frequency transmission section to the high-frequency reception section in a region other than the reception slot of the own station in the time slot divided by time division multiplexing. Switch to input. Thereby, the transmission output is input to the receiving circuit of the own station, and the receiving circuit detects the signal level. Using the signal level, the transmission power control circuit controls the transmission output of the high-frequency transmission unit.

[0010]

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing one configuration example of transmission output control of the present invention in a time division multiplex communication device. In FIG. 1, reference numeral 1 denotes an antenna that transmits and receives high-frequency signals as radio waves.

Reference numeral 2 denotes a transmission / reception switching circuit that receives a transmission signal from the high-frequency transmitting unit 5 and switches between outputting the signal to the antenna 1 and outputting to the high-frequency receiving unit 3. The high-frequency receiving unit 3 receives a high-frequency signal,
The signal is converted into an audio signal or the like by demodulation and amplification.

Reference numeral 4 denotes a received electric field strength monitor signal detected by the high frequency receiving section 3, which indicates a received signal level. The high-frequency transmission unit 5 receives an audio signal or the like and converts it into a high-frequency signal by modulation, amplification, or the like. Reference numeral 6 denotes a transmission power control circuit that controls the transmission output of the high-frequency transmission unit 5 according to the level of the reception field strength monitor signal 4.

Reference numeral 7 denotes a reception switching signal. When this signal is active, the time slot at that time among the divided time slots in the time division multiplex communication is the reception slot area of the own station. Is shown. 8
Is a transmission switching signal. When this signal is active, it indicates that the time slot at that time among the divided time slots in the time division multiplex communication is the transmission slot area of the own station.

[0014] receiving switching signals 7 and transmit switching signals 8, like the conventional example, in time division multiplex communication, with respect to the fixed station and the mobile station from the (Master) (slave device), to synchronize the time slots between parent and child Is output based on the transmitted synchronization signal. FIG. 2 is a detailed block diagram showing one configuration example of the transmission / reception switching circuit 2 of the present invention. In FIG. 2, the transmission / reception switching circuit 2 includes three switches SW1, SW2, SW3 and an attenuator R.

The switch SW1 transmits a transmission signal input from the high-frequency transmission unit 5 via the switch SW3 to the antenna 1
Or the reception signal input from the antenna 1 is input to the high-frequency reception unit 3 via the switch SW2. The switch SW2 sets the input to the high-frequency receiving unit 3 to a received signal input from the antenna 1 via the switch SW1, or a transmission signal input from the high-frequency transmitting unit 5 via the switch SW3 and the attenuator R. Switch.

The switch SW3 converts the transmission signal output from the high-frequency transmission unit 5 into a transmission signal of the antenna 1 via the switch SW1 or an input signal to the high-frequency reception unit 3 via the attenuator R and the switch SW2. Is switched. When the transmission signal output from the high-frequency transmission unit 5 is used as an input signal to the high-frequency reception unit 3 via the switch SW3, the attenuator R, and the switch SW2, the attenuator R converts the transmission signal to the high-frequency reception unit. Any amount is attenuated to adjust the level below the maximum allowable input. Further, if the attenuator R is of a variable type, it is possible to perform variable level adjustment that is useful for absorbing variations in equipment during mass production.

The operation of the transmission power control device configured as described above will be described. The divided time slots in the time division multiplex communication are as follows.
It can be broadly divided into three areas: a receiving slot area of the own station, a transmitting slot area of the own station, a transmitting slot of the own station, and an area other than the receiving slot. The switching signal input to the transmission / reception switching circuit 2 corresponding to the following transitions as follows.
That is, in the case of, only the reception switching signal 7 is active, and in the case of, only the transmission switching signal 8 is active.

Of the above slots (1), the operation in (the reception slot of the own station) is the same as that of the conventional apparatus, and therefore the description is omitted, and the following slots are described. The slot for convenience of explanation will be described first. When the area is neither the transmission slot of the own station nor the reception slot of the own station, the transmission / reception switching circuit 2 determines that the switch SW3
Between b-c becomes the connected state, by receiving the switching signal 7 is inactive, the switch SW 2 a-
between c, between the b-c switch SW 1 is connected.

Therefore, the transmission signal of the high-frequency transmission unit 5 is input to the high-frequency reception unit 3 via the switch SW3, the attenuator R, and the switch SW2. 1 is not supplied. Unnecessary high-frequency signals received by the antenna 1 are open between a and c of the switch SW1.
It is not supplied to the high frequency receiving unit 3.

When the transmission output from the high-frequency transmitting section 5 is input to the high-frequency receiving section 3, the high-frequency receiving section 3 outputs a received electric field strength monitor signal 4. Based on this signal, the transmission power control circuit 6 outputs a signal for controlling the power gain or the bias circuit of the high-frequency transmission unit 5 and controls the transmission output of the high-frequency transmission unit 5. At the same time, the transmission power control circuit 6
Holds the level of the received electric field strength monitor signal 4.

In the transmission slot area of the own station, the transmission / reception switching circuit 2 determines that the transmission switching signal 8 is active, the connection between a and c of the switch SW3 is in a connected state, and the reception switching signal 7 is non-active. As a result, the switch S1
The connection between a and c of W2 is established. Therefore, the transmission signal of the high-frequency transmission unit 5 includes the switch SW3 and the switch SW
1 is transmitted from the antenna 1, and the high-frequency transmission unit 5 is in a state of transmitting to the outside.

In this case, since the transmission power control circuit 6 holds the level of the received electric field strength monitor signal 4 in the previous slot, the transmission output of the high-frequency transmitting section 5 outputs the held received electric field strength monitor signal 4 Will be statically controlled according to the level of The transmission output control device repeatedly executes the above-mentioned time slots in order at a predetermined cycle. Therefore, in each time slot, the reception electric field intensity monitor held by the transmission power control circuit 6 in the previous time slot is used. The transmission output is controlled based on the level of the signal 4. As for the cycle, for example, to accommodate four lines in one frequency,
If one slot 0.625 ms is time-division multiplexed into eight time slots (four reception slots and four transmission slots), the period is 5 ms, and the control is 3.7 ms,
Is 0.625 ms.

In the present embodiment, in the case of (transmission slot of own station), a transmission signal is not input to the high frequency receiving unit 3 of the own station, but static control is performed.
It is also possible to supply a transmission output to the high frequency receiving unit 3 to perform dynamic control. For example, this method is useful when one line is accommodated in one frequency and time division multiplexing is performed in two time slots (one reception slot and one transmission slot).

[0024]

According to the present invention described above, the high-frequency transmission output is monitored by using the high-frequency reception unit originally provided in the digital mobile radio communication apparatus, and the output is controlled. It is not necessary to arrange a transmission output monitoring circuit such as a directional coupler between the high-frequency transmission unit and the antenna as in the related art, and therefore, the insertion loss of the transmission output monitoring circuit does not occur, and the transmission power is accordingly reduced. This has the effect of eliminating the loss. Therefore, the output power setting of the high-frequency transmission unit 25 does not require a level setting in which the loss of the transmission output monitor circuit 23 is added, and the power efficiency of the transmission output is improved.

In addition, since a transmission output monitoring circuit such as a directional coupler is not required, the circuit scale is reduced.
There is an effect that the size of the circuit and the size of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of transmission power control according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a transmission / reception switching circuit in the embodiment.

FIG. 3 is a block diagram illustrating a configuration of transmission power control according to the related art.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 antenna 2 transmission / reception switching circuit 3 high frequency reception unit 4 reception electric field strength monitor signal 5 high frequency transmission unit 6 transmission power control circuit 7 reception switching signal 8 transmission switching signal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04B 1/02-1/04 H04B 1/38-1/58 H04B 7/24-7/26 102 H04Q 7 / 00-7/38

Claims (2)

(57) [Claims] 1. A time division RF transmitter unit by multiplex communication, Shin
In a digital mobile radio communication device having a high-frequency receiving section for detecting a signal level , an antenna transmission / reception switching circuit, and a transmission power control circuit, the transmission / reception switching circuit performs reception of its own station during a time slot divided by time division multiplexing. In a region other than the slot, the transmission output is configured to be input to the high-frequency reception unit of the own station, and the transmission power control circuit uses the signal level of the transmission output of the own station detected by the high-frequency reception unit to transmit the transmission output. A transmission output control device configured to control the transmission power. 2. A high-frequency transmission unit using time division multiplex communication,
Frequency receiving section, antenna transmission / reception switching circuit, transmission power control
In a digital mobile radio communication device having a control circuit, The transmission / reception switching circuit is divided by time division multiplexing.
During timeslots, other than the own station's reception and transmission slots
In the area, input the transmission output to the high-frequency receiver of your own station.
The transmission power control circuit is configured to
Using the signal level of its own transmission output detected by the
The transmission power is controlled.
Transmission output control device.