JP2956807B2 - Diversity receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diversity receiver for a portable digital cellular radio, and more particularly to a diversity receiver for a digital cellular telephone.

[0002]

2. Description of the Related Art In a digital radio, a diversity system is adopted in a receiving unit in order to avoid an increase in a code error of a received output due to multipath fading, and two receivers connected to different antennas are provided. . In addition, since it is necessary to receive a call signal from the base station other than during a call and operate the receiver, the receiver is operated intermittently at the time of standby, as shown in FIG. Both receivers are operating. (For example, NTT Nagayama et al., IEICE Technical Report (Communication System) CS8
5-18, 1985)

[0003]

Conventionally, the use of digital radios is mainly for in-vehicle use, and since the moving speed is large and the intensity of the received electric field changes drastically, two digital receivers are used as in the prior art. Therefore, it is necessary to perform the diversity operation and perform the standby operation. However, at present, use as a portable device has become mainstream, and since the moving speed is lower than that of an automobile, the intensity of the received electric field changes slowly, so that
At the time of standby operation, it is not necessary to operate two receivers at the same time until some signal is detected, so that wasteful power is consumed. This is a serious problem for applications with limited battery capacity, such as mobile phones.

An object of the present invention is to provide a diversity receiver that consumes less power during standby reception.

It is another object of the present invention to provide a cellular telephone terminal which consumes less power during standby reception.

[0006]

The above object is achieved by stopping the diversity operation during the standby operation, and operating only one of the two receiving units and stopping the other.

[0007]

According to the present invention, during standby operation, only one of the two receivers is alternately operated in time and the other is stopped, thereby reducing power consumption as compared with the conventional method. Can be achieved.

[0008]

FIG. 1 is a diagram showing one embodiment of the present invention.
In cases other than the standby operation (in a state in which the standby mode signal 14 is not valid), the power on / off circuit 9 for the receiver 1, the power on / off circuit 10 for the receiver 2, and the power on / off circuit 11 for the diversity unit are respectively In the closed state, the output signals of the receiver 1 to which the antenna 3 is connected and the receiver 2 to which the antenna 4 is connected, and the electric field strength measurement signals respectively output from the receiver 1 and the receiver 2 are also shown. At the same time, a diversity operation is performed to switch from the diversity unit 5 to the receiver output having a stronger signal strength via the standby control unit. At this time, the standby control unit 13 performs an operation of switching the outputs of both receivers according to the diversity output. On the other hand, a standby state is set and the standby mode signal 1
4, the standby control unit 13 disconnects the power on / off circuit 10 for the receiver 2 and the power on / off circuit 11 for the diversity unit, and turns on / off the power for the receiver 1.
The disconnection circuit 9 is turned on, and the output selection circuit 12 is held with the output of the receiver 1 selected. Accordingly, the standby operation stops the diversity operation, and only the output of the receiver 1 always appears in the reception output 15. In this embodiment, since the diversity operation is stopped during the standby operation and one of the receivers is stopped, the power consumption can be reduced to half of that in the case where the diversity operation is always performed. it can.

FIG. 2 is a block diagram of a receiver showing another embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals.
It differs from FIG. 1 in that two receivers are alternately switched. The operation at the time of normal reception is the same as in FIG. When the standby mode signal 14 is detected and the standby mode signal 14 is detected, the standby control unit 13 turns off the diversity unit power on / off circuit 11 to stop the diversity operation, and then the power on / off circuit 9 for the receiver 1. The power on / off circuit 10 for the receiver 2 is alternately turned on and off in accordance with the intermittent operation timing signal 16, and the output selection circuit 12 also operates among the receivers 1 and 2 according to the intermittent operation timing signal. A switching operation is performed so as to select the output which is present. Therefore, the receiver 1 during standby operation
The receiver 2 alternately operates at each timing of the intermittent operation, and the output of the receiver 1 and the receiver 2 alternately appears at the reception output 15 at each timing of the intermittent operation. In the configuration of FIG. 1, it is conceivable that a receiver performing a standby operation may not obtain a required reception electric field depending on the position of the antenna or the like. Is stopped, the power consumption can be reduced compared to the case where diversity operation is always performed, and there is a possibility that one of the receivers can obtain a necessary and sufficient reception electric field. Since it is higher, the standby operation can be performed reliably.

FIG. 3 is a block diagram showing a receiver according to still another embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals. Electric field strength measurement circuit 1 for weighting reception output
7 and 18 are different from FIG. 2 in that the frequency of switching between the two receivers is controlled by the standby control unit 13 in accordance with the weight signal obtained by the addition. The operation at the time of normal reception is the same as in FIG. FIG. 4 is a timing chart showing the operation at the time of the standby operation of the present embodiment.
Upon detecting the standby mode signal 14, the standby control unit 13 turns off the diversity unit power on / off circuit 11 to stop the diversity operation, and the electric field strength measurement circuit 17 connected to the receiver 1 and the receiver 2. From the weight signals 19 and 20 obtained each time the receiver operates according to 18 and the average value of the reception electric field weights of the two receivers in a certain section before that, the ratio at which the receiver with the stronger reception electric field operates operates. The frequency of switching between both receivers is determined so as to increase, and the reception output is switched at each intermittent reception timing accordingly. Further, if the switching frequency is set so as to be biased toward only one receiver, for example, 10 to 0,
On the other hand, even if the reception electric field strength becomes large, there is a possibility that the receiver is switched to the receiver having the smaller reception electric field strength, so that it is necessary to provide a certain threshold value. According to the configuration of the present embodiment, the reception electric field strengths of the two receivers are weighted and the receivers are switched in accordance with the weights. Therefore, since one of the receivers is stopped, the diversity operation is always performed. Power consumption can be reduced as compared with the case where the receiver is switched, and the possibility that the output of the receiver having a higher received electric field strength appears in the reception output 15 as compared with the method of simply switching the receiver is higher. Thus, the standby operation can be stably performed.

[0011]

As described above, according to the present invention, the power consumption can be reduced by operating only one system of the receiver during the standby operation.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a receiver showing one embodiment of the present invention.

FIG. 2 is a configuration diagram of a receiver showing another embodiment of the present invention.

FIG. 3 is a configuration diagram of a receiver showing another embodiment of the present invention.

FIG. 4 is a timing chart showing signals of respective parts of the embodiment shown in FIG.

FIG. 5 is a diagram showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Receiver, 2 ... Receiver, 3 ... Antenna, 4 ... Antenna, 5 ... Diversity part, 6 ... Power supply for receiver 1, 7 ... Power supply for receiver 2, 8 ... Power supply for diversity part, 9 ... Receiver Power on / off circuit for 1; 10 ... Power on / off for receiver 2 /
Disconnection circuit, 11: power-on / off circuit for diversity section, 12: output selection circuit, 13: standby control section, 14
... standby mode signal, 15 ... reception output, 16 ... interval operation timing signal, 17 ... electric field strength measurement circuit, 18 ...
Electric field strength measurement circuit, 19: weight signal of receiver 1 output, 2
0: a weight signal of the receiver 2 output

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-303231 (JP, A) JP-A-57-80835 (JP, A) JP-A-62-230125 (JP, A) JP-A-3-302 175749 (JP, A) JP-A-1-293743 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04B 7/24-7/26 102 H04Q 7/00-7/38

Claims (1)

(57) [Claims] A first antenna; a second antenna;
A first receiver connected to the first antenna;
A second receiver connected to the first and second antennas;
Electric field strength for measuring the electric field strength output from the second receiver
And a first measuring device and a second measuring device in a standby mode.
A control unit for controlling switching of the receiver, wherein the control
The switching unit switches the first and second receivers.
The first receiver or the second receiver obtained from a field strength measuring instrument.
Receiver weight signal and both receivers within a certain interval before that
From the weighted average of the received signal from the
Operation of the receiver increases the operating ratio of the receiver.
Comb, and the operating ratio of the receiver with small receiving electrolysis is 0 or less.
Radio control characterized by switching control so that it does not fall below
Terminal.