JP2002135184A - Diversity receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate need for filters and amplifiers to be provided for each of plural antennas, and prevent demodulated outputs from being influenced in antenna selection. SOLUTION: A level detectors 2a and 2b detect levels La and Lb of received signals, inputted from plural antennas 1a and 1b via plural input terminals 10a and 10b. A selector 3 is controlled by a selection controller 7 to select either of the signals from plural antennas 1a and 1b. An input filter 4 and amplifier 5 amplifiers the selected signal to the predetermined level. A demodulator 6 demodulates the outputs of the amplifier 5 and outputs a timing signal Pt, indicating a period of each of time-shared data. The selection controller 7 generates a selection signal Sc, which allows the selection of an antenna of the maximum signal level, to issue it to the selector 3 at an interval between data of the time-shared signal, based on signal levels La and Lb and on the timing signal Pt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diversity receiver.
The present invention relates to a diversity receiver that selects an antenna having good reception quality.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing an example of this type of conventional diversity receiver.

[0005] Input terminals 10a and 10b connected to a plurality of antennas 1a and 1b, respectively, and input terminals 10a
And input filters 12a and 12b that receive signals input to input signals 10b and extract desired received signal components, respectively.
b, amplifiers 13a and 13b for amplifying the outputs of input filters 12a and 12b, respectively, and amplifier 13a
Switch 1 for selecting any one of the outputs of 13 and 13b
4, a demodulator 15 for demodulating the signal selected by the switch 14 and outputting a signal indicating the signal quality, and an antenna having a good signal quality based on the signal indicating the signal quality output from the demodulator 15. And a switching controller 16 for controlling the switching unit 14 to make a selection.

The switching controller 16 monitors a signal indicating the signal quality output from the demodulator 15 and monitors, for example, the signal level and the number of data errors, so as to select an antenna having a good signal quality. Control unit 14.

[0005]

In the above-mentioned conventional example,
An input filter and an amplifier for receiving and amplifying signals received from a plurality of antennas are provided for each antenna. For this reason, the circuit scale becomes large, which is a factor of increasing cost and power consumption.

Further, when the antenna is switched, the signal path changes, which causes a difference in the arrival time (group delay amount) of the received signal, which affects demodulation output.

An object of the present invention is to provide a diversity receiver which does not provide a filter and an amplifier for each of a plurality of antennas and does not affect the demodulation output when the antennas are switched.

[0008]

SUMMARY OF THE INVENTION A diversity receiver according to the present invention is a diversity receiver for comparing time-division signals received by a plurality of antennas, selecting an antenna having good reception quality, and receiving and demodulating. Means for detecting the signal levels of the received signals at the plurality of input terminals respectively connected to the plurality of antennas, selecting the antenna having the largest signal level, and switching at the timing that does not hinder the demodulation output.

More specifically, level detecting means for detecting signal levels of received signals at a plurality of input terminals respectively connected to a plurality of antennas, and any one of signals inputted through the plurality of input terminals A switching unit for selecting one according to the switching signal; an amplifying unit for amplifying the signal selected by the switching unit; and an output of the amplifying unit. A demodulation unit that outputs a timing signal; and a switching control unit that generates the switching signal based on the signal level and the timing signal and transmits the switching signal to the switching unit.

The switching control means compares the signal levels detected by the level detection means and selects an antenna having the maximum signal level, and switches based on a timing signal output from the demodulation means. A switching timing generation circuit that generates a timing signal; and a switching signal generation circuit that generates and sends the switching signal in accordance with the comparison result of the comparison circuit and the switching timing signal.

In the above configuration, the switching timing generation circuit adjusts the timing of the timing signal in accordance with the delay time of the signal in the amplifying means, so that each of the time-divided received signals input to the switching means is divided. A signal indicating an interval between data is generated and output as the switching timing signal.

Further, the switching signal generation circuit, when the comparison result of the comparison circuit is changed to an antenna different from the antenna which has already been selected, sends the switching signal to the switching means in accordance with the switching timing signal. Send out.

A diversity receiver according to the present invention is a diversity receiver that compares time-division signals received by a plurality of antennas, selects an antenna having good reception quality, and demodulates the received signal. Level detection means for respectively detecting the signal levels of the received signals at the plurality of input terminals connected thereto, and switching means for selecting any one of the signals input through the plurality of input terminals in accordance with the switching signal; A working and standby amplifying means for amplifying the signal selected by the switching means, and a timing signal indicating a period of data divided by a fixed period and demodulating outputs of the working and standby amplifying units, respectively. Working and protection demodulation means for outputting, and the tag output from the working and protection demodulation means in response to switching of the working and protection. A switch that selects one of the timing signals, and a switching control unit that generates the switching signal based on the signal level and the timing signal selected by the switch and sends the switching signal to the switching unit, wherein the switching control unit includes: Between a comparison circuit that compares the signal levels detected by the level detection means and selects an antenna having the largest signal level, and between each data of a reception signal input to the switching means based on the timing signal selected by the switch; And a switching signal generating circuit for generating and transmitting the switching signal according to the comparison result of the comparing circuit and the switching timing signal.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. Here, the received signal is, for example, a time-division signal in which data is divided at a fixed period and a fixed interval is provided between the divided data, as shown in FIG.

In FIG. 1, a plurality of input terminals 10a and 1a connected to a plurality of antennas 1a and 1b, respectively.
0b, a plurality of level detectors 2a and 2b for detecting signal levels La and Lb of signals input to a plurality of input terminals 10a and 10b, respectively, and a plurality of input terminals 10a and 10b.
a switch 3 for selecting any one of the signals input through the switches a and b, an input filter 4 for receiving a signal selected by the switch 3 and extracting a desired received signal component; 4, an amplifier 5 for amplifying the output of the amplifier 4 to a predetermined level, a demodulator 6 for demodulating the output of the amplifier 5 and outputting a timing signal Pt indicating a period of time-divided data, and a plurality of level detectors 2a and 2b. Switch 3 based on the signal levels La and Lb output from the demodulator 6 and the timing signal Pt output from the demodulator 6, respectively.
And a switching controller 7 for controlling the

By the way, in order to switch the antenna so as not to affect the demodulation output, the signal (time-division signal) input from the antenna may be switched to the interval shown in FIG.

The level detectors 2a and 2b are composed of, for example, a narrow-band amplifier and a detector, and output the detected received signal levels La and Lb, respectively.

As shown in FIG. 2, the switching controller 7 includes a comparison circuit 71 for comparing the signal levels La and Lb of the antennas 1a and 1b, and a timing signal P output from the demodulator 6.
A switching timing generation circuit 72 that generates a signal St indicating switching timing based on t, and a switching signal generation circuit 73 that sends a switching signal Sc to the switch 3 at the time of antenna switching.

The switching timing generation circuit 72 includes a demodulator 6
A signal indicating the interval of the time-division signal input to the switch 3, based on the timing signal Pt output from
That is, the switching timing signal St is generated.

Next, the operation of the switching controller 7 will be described.

FIG. 3 is a flowchart showing the operation of the switching controller 7.

First, the comparison circuit 71 determines whether the antennas 1a, 1b
Are compared with each other (step 10).
1). Here, if La> = Lb, the antenna 1
a is selected (step 102).

At this time, if the antenna 1a has already been selected, there is no need to switch the antenna, so the switching signal generation circuit 73 does not instruct the switching unit 3 to perform a switching operation.
If the antenna 1b has already been selected, the antenna 1b is switched to the antenna 1a (step 103).

In this case, the switching signal generating circuit 73 switches the switching signal Sc for switching from the antenna 1b to the antenna 1a according to the switching timing signal St indicating the interval of the received signal, that is, at the interval of the received signal (step 104). (Step 10)
5).

On the other hand, as a result of comparing the signal levels La and Lb in step 101, if Lb> La,
The antenna 1b is selected (Step 102).

At this time, if the antenna 1b has already been selected, there is no need to switch the antenna. If the antenna 1a has already been selected, the antenna 1a is switched to the antenna 1b (step 106).

In this case, the switching signal generation circuit 73 switches the switching signal Sc for switching from the antenna 1a to the antenna 1b according to the switching timing signal St indicating the interval of the received signal, that is, at the interval of the received signal (step 107). (Step 10)
8). The above steps are continued until the receiver stops operating (step 109).

FIG. 4 is a diagram showing the timing of antenna switching, showing a case where the antenna 1a is already selected and the antenna 1a is switched to the antenna 1b.

As shown in FIG. 3A, the signal levels La,
When Lb has changed, Lb> La from time T1 onward, and the comparison result shown in FIG.

Here, when the switching timing signal St is in the state shown in FIG. 5C, the received signal input from the antenna is in the state shown in FIG.
If the switching signal Sc for switching from the antenna 1a to the antenna 1b is transmitted at the time (T2) of the first switching timing signal St after changing to> La, the switching can be performed without affecting the demodulation output.

FIG. 6 is a block diagram showing another embodiment of the present invention.

Here, an example is shown in which a working spare configuration is used to improve the reliability as a receiver. The same components as those shown in FIG. 1 are denoted by the same reference numerals.

In FIG. 6, the output side of the switch 3 has a working input filter 4-1, an amplifier 5-1 and a demodulator 6-6-1.
1, and a standby input filter 4-2 and an amplifier 5-2
And a demodulator 6-2.

The switches 8 and 9 are operated in accordance with the switching of the working spare.
The switch 9 selects one of the timing signals Pt1 and Pt2 output from the demodulators 6-1 and 6-2, respectively.

[0036] By doing so, it is possible to provide a working standby receiver which does not affect the demodulation output when the antenna is switched.

In the above description, two antennas are used, but it is apparent that three or more antennas function similarly.

[0038]

As described above, according to the present invention, one of signals (time-division signals) from a plurality of antennas input through a plurality of input terminals is selected by a switch, and input is performed. The signal is demodulated by passing through a filter and an amplifier, a signal (switching timing signal) indicating an interval between time-division data is generated, and a received signal is received at a plurality of input terminals respectively connected to a plurality of antennas. By detecting each signal level and selecting and switching the antenna having the largest signal level based on these signal levels and the switching timing signal, it is not necessary to provide a filter and an amplifier for each of the plurality of antennas, and the circuit scale and Lower costs and power consumption,
Further, when the antenna is switched, the demodulated output is not affected.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing an example of a switching controller 7 shown in FIG.

FIG. 3 is a flowchart showing an operation of a switching controller 7 shown in FIG.

FIG. 4 is a diagram showing antenna switching timing.

FIG. 5 is a diagram illustrating a configuration example of a reception signal.

FIG. 6 is a block diagram showing another embodiment of the present invention.

FIG. 7 is a block diagram showing a conventional example.

[Description of Signs] 1 antenna 2 level detector 3 switch 4 input filter 5 amplifier 6 demodulator 7 switch controller 10 input terminal 71 comparison circuit 72 switching timing generation circuit 73 switching signal generation circuit Pt timing signal Sc switching signal St switching Timing signal

Claims (8)

[Claims] 1. A diversity receiver for comparing time-division signals received by a plurality of antennas, selecting an antenna with good reception quality, and receiving and demodulating the plurality of antennas, wherein a plurality of inputs respectively connected to the plurality of antennas are provided. A diversity receiver comprising: means for detecting a signal level of a reception signal at an end, selecting an antenna having the maximum signal level, and switching the antenna at a timing that does not hinder demodulation output. 2. A diversity receiver for comparing time-division signals received by a plurality of antennas, selecting an antenna having good reception quality, and performing reception demodulation, wherein a plurality of inputs connected to the plurality of antennas, respectively. Level detecting means for respectively detecting the signal level of the received signal at the end,
Switching means for selecting any one of the signals input through the plurality of input terminals according to a switching signal; amplifying means for amplifying the signal selected by the switching means; and an output of the amplifying means. Demodulation means for demodulating and outputting a timing signal indicating a cycle of time-divided data at a fixed cycle, and switching control means for generating the switching signal based on the signal level and the timing signal and transmitting the switching signal to the switching means. A diversity receiver, comprising: 3. The switching control unit compares the signal level detected by the level detection unit and selects an antenna having the maximum signal level, and switches based on a timing signal output from the demodulation unit. 3. The switching circuit according to claim 2, further comprising: a switching timing generation circuit that generates a timing signal; and a switching signal generation circuit that generates and sends the switching signal in accordance with a comparison result of the comparison circuit and the switching timing signal. Diversity receiver. 4. The switching timing generation circuit according to claim 3, wherein the switching timing generation circuit generates the switching timing signal by adjusting the timing of the timing signal in accordance with a delay time of the signal in the amplifying unit. Diversity receiver. 5. The switching timing signal generated by the switching timing generation circuit is a signal indicating an interval between each time-divided data of a reception signal input to the switching means. The described diversity receiver. 6. The switching signal generation circuit, when the comparison result of the comparison circuit changes to an antenna different from the already selected antenna, sends the switching signal to the switching means in accordance with the switching timing signal. 4. The diversity receiver according to claim 3, wherein the signal is transmitted. 7. A diversity receiver for comparing time-division signals received by a plurality of antennas, selecting an antenna having good reception quality, and performing reception demodulation, wherein a plurality of inputs connected to the plurality of antennas, respectively. Level detecting means for respectively detecting the signal level of the received signal at the end,
Switching means for selecting any one of the signals input through the plurality of input terminals in accordance with a switching signal; working and standby amplification means for amplifying the signal selected by the switching means; Working and backup demodulating means for respectively demodulating the outputs of the backup amplifying means and outputting timing signals indicating the cycle of the time-divided data at a fixed cycle, and A switch for selecting one of the timing signals output from the demodulation unit; and a switching control unit for generating the switching signal based on the signal level and the timing signal selected by the switch and transmitting the switching signal to the switching unit. A diversity receiver characterized by the above-mentioned. 8. The switching control means compares the signal level detected by the level detection means and selects an antenna having the maximum signal level, and the switching circuit based on a timing signal selected by the switch. A switching timing generating circuit for generating a switching timing signal indicating an interval between each data of the received signal input to the means, and a switching signal for generating and transmitting the switching signal in accordance with the comparison result of the comparison circuit and the switching timing signal The diversity receiver according to claim 7, further comprising a generation circuit.