JPH1070480A - Reception path automatic selection changeover system using a/d converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify circuit configuration and to attain a quick and optimum reception path. SOLUTION: Each of A/D converters 41, 42,...4n is connected to each of a plurality of reception circuits 11, 12,...1n, and a reception electric field intensity signal outputted from each of the reception circuits 11, 12,...1n is converted digitally by each of the A/D converters 41, 42,...4n simultaneously. The simultaneously converted signals are compared by a digital comparator 5. In the digital comparator 5, the quantity of levels of the digitally converted reception electric field intensity is compared and a highest level is selected. Based on the comparison result by the digital comparator 5, a changeover device 2 selects a reception path to the reception circuit at a highest level of the reception electric field intensity immediately and a reception signal of the reception circuit is fed to a demodulation circuit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for automatically selecting a receiving path using an AD converter for switching a path to a receiving circuit having the highest received electric field strength in a wireless device having a plurality of receiving circuits.

[0002]

2. Description of the Related Art The configuration of a conventional receiving circuit switching system is shown in FIG. In this conventional system, a plurality of receiving circuits 11, 12,.
1n, one AD converter 7 is provided.
The received electric field strength signals from 1, 12,... 1n are sequentially switched and input by the switch 6 to perform analog-to-digital conversion. And the switching is performed by the switch 2 to the highest-level receiving circuit. The received signal is supplied to the demodulation circuit 3 from the reception circuit whose received electric field strength is switched to the highest level.

[0003]

As described above, conventionally, a complicated procedure is used for switching the route of the received signal. For this reason, software for signal conversion, comparison, and switching was required, and the processing time required several tens μs to ms.

On the other hand, the received electric field intensity signal output from each receiving circuit is changing every moment as shown in FIG. The reception field strength of the AD-converted signal A received field strength signal A at time t ₄₁ now (A), AD received field strength signal B at time t ₄₂
Assuming that the received electric field strength of the converted signal B is (B),
Size determination of the (A) and (B) takes place between times t ₄₂ ~ time t _43, the comparison result is (A)> (B), the system path switching at time t ₄₃ in the A-side based on this Is performed. However, towards the reception electric field intensity signal B to in already at time t ₄₃ the system path switching is performed is larger than the reception electric field intensity signal A.

[0005] When the signal change is abrupt as described above, there has been a problem that the optimal system switching cannot be performed.

An object of the present invention is to solve such a conventional problem and to enable quick and optimal switching of the receiving system without the intervention of a microcomputer and software.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an AD converter for performing analog-to-digital conversion of received electric field intensity signals of a plurality of receiving circuits, and a digital converter for comparing the digital converted outputs to select a highest level signal. This is achieved by providing a comparator and a switching circuit for switching the receiving path to the highest level receiving circuit based on the output signal of the comparator.

According to the above means, the received electric field intensity signals output from the respective receiving circuits are simultaneously converted by the connected AD converters, and the converted outputs are compared by the digital comparator. The switching circuit immediately switches the receiving path to the highest level receiving circuit based on the comparison result. This makes it possible to always optimally switch the receiving system.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, which is a radio having a plurality of receiving circuits 11, 12,... Absent. .. 1n are connected to AD converters 41, 42,. .. 1n output from the receiving circuits 11, 12,... 1n are simultaneously digital-converted by the AD converters 41, 42,. The signals converted at the same time are compared by the digital comparator 5. The comparison by the digital comparator 5 compares the levels of the digitally converted received electric field strengths and selects the highest level. This digital comparator 5
Based on the comparison result, the switch 2 immediately switches the receiving path to the receiving circuit with the highest received electric field strength, and the received signal of the receiving circuit is supplied to the demodulation circuit 3.

FIG. 2 shows the relationship between the input of the received field strength signal, conversion, and switching on the time axis. Receiving circuits 11, 12,
The levels of the received electric field strength signals A and B of... 1n are temporally changed as shown in FIG. Accordingly, AD converter 41 and 42 at time t _21, ... 4n obtain signals A and simultaneously converting converts signals B (A) (B) with. At the same time, the levels are compared by the digital comparator 5, and the comparison result (A)>
(B) is obtained. Switching the reception system path signal A side switch 2 immediately in time t ₂₂ based on this. Furthermore, AD converter 41 and 42 at the next time t _23, ... 4n simultaneously converting the signals A and B by converting the signal (A), to give (B), comparing the levels at the digital comparator 5 simultaneously compare The result (A) <(B) is obtained. Thus at time t ₂₄ to switch the reception system path signal B side switch 2 is performed.

The received signal of the receiving circuit switched in this way is supplied to the demodulation circuit 3, and the optimum received signal at the highest level can always be selected and received.

[0013]

By implementing the present invention as described above, it is possible to quickly and optimally switch the receiving system.

Further, since the circuit configuration is simplified without using a conventional microcomputer and software, it can be provided at a low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a received field strength signal and conversion / switching according to the present invention.

FIG. 3 is a conventional configuration diagram.

FIG. 4 is an explanatory diagram showing the relationship between a conventional received field strength signal and conversion / switching.

[Explanation of symbols]

11, 12 ... 1n receiving circuit, 2 ... switch, 3 ... demodulation circuit, 41, 42 ... 4n ... AD converter, 5 ... digital comparator.

Claims (1)

[Claims] In an automatic receiving system selection method for a radio having a plurality of receiving circuits, an AD converter for performing analog-to-digital conversion of received electric field strength signals of a plurality of receiving circuits is compared with the digital conversion output. A digital comparator for selecting a highest level signal and a switching circuit for switching a receiving path to a highest level receiving circuit based on an output signal of the comparator. Automatic route selection switching method.