JPH04334212A - Low power consumption type demodulator - Google Patents

Abstract

PURPOSE:To use a system used even if diversity is selected or not and to reduce power consumption when diversity is not selected in a demodulator used for various mobile communication equipment. CONSTITUTION:When diversity is selected, respective systems obtain a modulated signal 13 from a reception signal 12 by receiving circuits 11. Furthermore, demodulation circuits 16 are given a demodulation circuit original vibration 17 and all the systems are given a demodulation circuit control signal 19 from a control means 18 so as to turn the systems into an operation mode. Thus, a diversity selection circuit 20 selects the system in a satisfactory receiving state by a diversity selection signal 21. When the same demodulator 14 is used at the time when deversity is not selected, only one of the modulation circuits 16 by the demodulation circuit control signal 19 is turned into the operation mode, and the other systems are set to be in a shutting off mode.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a demodulator of a low power consumption type, which requires low power consumption, such as a portable communication device.

0002

2. Description of the Related Art FIG. 3 is a schematic block diagram of a conventional demodulator and peripheral circuits for performing diversity selection. In FIG. 3, a receiving circuit 1 converts a received signal 2 into a modulated signal 3. 4 is a demodulator, which receives the modulated signal 3
is demodulated into demodulated data 5. Inside the demodulator 4,
Reference numeral 6 denotes a demodulation circuit, which operates by applying the demodulation circuit original oscillator 7, demodulates the modulated signal 3, and outputs it to the diversity selection circuit 8. Diversity selection circuit 8 selects a system with a good reception condition among the demodulated data of each system using diversity selection signal 9, and outputs it as demodulated data 5 to demodulator 4.

In such a demodulator, when performing diversity selection, the receiving circuit 1 has multiple systems from the first system 1-1 to the Nth system (N≧2) 1-N, and within the demodulator 4, each system is It has demodulation circuits 6-1 to 6-N corresponding to the systems, and a diversity selection circuit 8 selects one system with a good reception condition and outputs it as demodulated data 5.

On the other hand, when such a demodulator 4 is applied to a communication device that does not perform diversity selection as shown in FIG.
The modulated signal 3 is not input to N, and the selection system of the diversity selection circuit 8 is fixed to the first system.

[0005] In this manner, even in conventional communication equipment, the same demodulation circuit can be used for cases in which diversity selection is performed and cases in which diversity selection is not performed.

[0006]

However, in the conventional demodulator, when diversity selection is not performed as shown in FIG.
Even if there is only one system, the demodulation circuit original oscillation 7 is given to the demodulation circuits 6-1 to 6-N of the entire system, so the demodulation circuits 6-2 to 6-N of the second system to the Nth system There was a problem in that the system also operated, consuming unnecessary power.

[0007] Furthermore, when diversity selection is not performed, it is possible to use a demodulator having only one system of demodulation circuits, but in this case, such a demodulator must be newly prepared, and the demodulator itself There was a problem in that the versatility was reduced.

The present invention solves these conventional problems, and is versatile enough to be used in both cases where diversity selection is performed and when diversity selection is not performed, and low consumption when diversity selection is not performed. It is an object of the present invention to provide an excellent low power consumption type demodulator that can be powered.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention has a diversity selection circuit that selects a system with a good reception condition from a plurality of demodulation circuits, and when performing diversity selection, a plurality of demodulation circuits. The apparatus is equipped with a control means that operates all systems of the demodulation circuits and, when diversity selection is not performed, operates only one system of the plurality of demodulation circuits and stops the other systems.

0010

[Operation] Therefore, according to the present invention, when diversity selection is performed, the demodulation circuits of all systems are operated, and when diversity selection is not performed, only one system of demodulation circuits is operated, and other systems are operated. Since the demodulation circuit is stopped, the demodulation device can be used in common to provide versatility, and when diversity selection is not performed, further reduction in power consumption can be achieved.

[0011]

[Embodiment] An embodiment of the present invention will be described below. FIG. 1 is a schematic block diagram of a demodulator and peripheral circuits to which this embodiment is applied when performing diversity selection, and FIG.
1 is a schematic block diagram of a demodulator and peripheral circuits to which this embodiment is applied when diversity selection is not performed.

In these figures, 11 is a receiving circuit which converts a received signal 12 into a modulated signal 13. A demodulator 14 demodulates the modulated signal 13 into demodulated data 15. Inside the demodulator 14, 16 is a demodulator circuit, which operates by applying a demodulator control signal 19 from a demodulator source 17 and a control means 18, and demodulates the modulated signal 13 and outputs it to the diversity selection circuit 20. .

The receiving circuit 11 includes the first system 11-1 to the Nth system 11-1.
There are multiple systems (N≧2) up to 11-N, and demodulation circuits 16-1 to 16 are provided in the demodulator 14 corresponding to each system.
-N, and the diversity selection circuit 20 selects one system with a good reception condition using the diversity selection signal 21 and outputs it as demodulated data 15.

The demodulation circuit control signal 19 is the demodulation circuit original oscillator 1
7 are controlled at the entrances of the demodulation circuits 16-1 to 16-N of each system, and when the demodulation circuit control signal 19 is in the operation mode, the demodulation circuit original oscillation 17 is controlled by the demodulation circuits 16-1 to 16-N.
6-N for demodulation operation, and in the stop mode, the demodulation circuit source 17 is supplied to the demodulation circuits 16-1 to 16-N.
is stopped at the entrance of the demodulator circuits 16-1 to 1.
The operation of 6-N also stops completely.

Next, when the same demodulator 14 as shown in FIG. 1 is applied to a communication device that does not perform diversity selection as shown in FIG. Demodulation circuit 1 from 2nd system to Nth system
It is not input to 6-2 to 16-N, and the selection system of the diversity selection circuit 20 is fixed to the first system. That is,
The demodulation circuit control signal 19 controls the operation mode of only the first demodulation circuit 16-1 and the demodulation circuits 16-2 of the second to Nth systems.
to 16-N are placed in a stop mode, so that the only demodulation circuit 16 actually operating is the first system 16-1.

As described above, according to the above embodiment, when performing diversity selection, the demodulation circuit control signal 19 is set to the operation mode to control the demodulation circuits 16-1 to 16- of all systems.
When the same demodulator 14 is applied to a communication device that does not perform diversity selection, the demodulator control signal 19 is set to the operating mode of only one system of the demodulator circuit 16-1, and the demodulator circuit of the other system is set to the operating mode. By setting the demodulators 16-2 to 16-N in stop mode, the same demodulator 4 can be used both when diversity selection is performed and when diversity selection is not performed, and when diversity selection is not performed. This has the effect of reducing power consumption.

In the above embodiment, it goes without saying that the polarity of the operation mode and stop mode of the demodulation circuit control signal 19 may be reversed.

[0018]

As is clear from the above embodiments, the present invention has a diversity selection circuit that selects a system with a good reception condition from a plurality of demodulation circuits. If all systems of the demodulator are operated and diversity selection is not performed, one of the multiple demodulator circuits
Since it is equipped with a control means to operate only one system and stop the other systems, one and the same demodulator can be used in both communication equipment that performs diversity selection and communication equipment that does not, providing versatility. Furthermore, when diversity selection is not performed, it is possible to further reduce power consumption.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, and is a schematic block diagram of a demodulator and peripheral circuits when performing diversity selection.

[Fig. 2] A schematic block diagram of the demodulator and peripheral circuits in the same embodiment when diversity selection is not performed.

[Fig. 3] A schematic block diagram of a demodulator and peripheral circuits when performing diversity selection, showing a conventional example.

[Fig. 4] A schematic block diagram of a demodulator and peripheral circuits in the same conventional example when diversity selection is not performed.

[Explanation of symbols]

11 Receiving circuit 12 Received signal 13 Modulated signal 14 Demodulator 15 Demodulated data 16 Demodulation circuit 17 Demodulation circuit source oscillation 18 Control means 19 Demodulation circuit control signal 20 Diversity selection circuit 21 Diversity selection signal

Claims (1)

[Claims] [Claim 1] It has a diversity selection circuit that selects a system with a good reception condition from a plurality of demodulation circuits, and when diversity selection is performed, all systems of the plurality of demodulation circuits are operated, and when diversity selection is not performed, A low power consumption type demodulator includes a control means for operating only one system of a plurality of demodulation circuits and stopping the other systems.