JPH033429A - Space diversity equipment - Google Patents

Abstract

PURPOSE:To surely perform space diversity at every carrier by controlling a level detection signal after synthesizing with a control circuit in common to each carrier. CONSTITUTION:The device is equipped with branch circuits 6 and 7 which branch a reception signal to a signal at every carrier, and inphase synthesis circuits 81-8n which fetch carrier signals from the branch circuits 6 and 7, and synthesize the carrier signal on one side with the carrier signal on the other side via an infinite phase apparatus 81, and after that, eliminate the carrier with a band-pass filter 83, and perform the gain control of an elimination signal with an automatic gain control means 84. Also, it is equipped with a common control circuit 9 which controls the phase of the infinite phase apparatus 81 of each carrier so as to maximize an automatic gain control voltage at every carrier. Here, the control circuit 9 is comprised so that each output signal from each level detector 85 that is the automatic gain control voltage at every carrier can display the maximum value and the phase of the infinite phase apparatus 81 of each carrier can be controlled, In such a way, the space diversity can be surely performed with simple constitution compared with a multiple carrier system.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a space diversity method using a multicarrier modulation method that divides a band into a plurality of carrier waves and modulates each of the plurality of carrier waves to transmit a digital signal. The present invention relates to an apparatus, and particularly relates to a space diversity apparatus that can perform space diversity using the multicarrier modulation method with a simple configuration.

[Conventional technology]

Conventionally, in space diversity devices using a single carrier modulation method, a direct phase detection method or a sensing method has been widely used as a method for combining two signals into the same phase.

FIG. 3 is a block diagram showing a specific example of a space diversity device that employs the direct phase detection method.

In FIG. 3, the received signal from the antenna 11.12 can be fed to a receiver 13.14 having a frequency conversion function. A local oscillation frequency is supplied to the receiver 13 directly from a local oscillator 15, and to the receiver 14 from the local oscillator 15 via an infinite phase shifter 16. The phases of each output signal from each receiver 13 and 14 are compared by a phase comparator 17, and the comparison result is provided to an infinite phase shifter control circuit 18. The infinite phase shifter control circuit 18 controls the infinite phase shifter 16 according to the comparison result. Further, the output signals from each receiver 13 and 14 are combined by a combiner 19 and output as a space-diversified output signal.

According to this device, the received signal from the antenna 11.12 is frequency-converted at the reception 1113.14 and is then frequency-converted by the combiner 19
The signals are supplied to the synthesizer 19, synthesized, and output. The output signals of the receivers 13 and 14, which are the reception modulation frequencies of the two systems, are directly compared in phase by the phase comparator 17, and the infinite phase shifter control circuit 1 is configured to make the comparison result zero in the in-phase state.
Infinite phase 2116 is controlled at 8.

〔Problems to be solved〕

However, when trying to apply the space diversity method of the above device to all carriers in a multicarrier modulation system that has multiple modulated waves, it is not necessary to apply each carrier in a fading propagation path with frequency selectivity. It does not necessarily converge to the optimal in-phase synthesis state in each case.

Therefore, if an infinite phase shifter is provided for each carrier and phase detection control as shown in FIG. 3 is performed individually, the space diversity device becomes optimal for selective fading. However, a phase comparator 17 and a control circuit 18 having a frequency component extraction function and an automatic gain control function are required for each carrier wave, resulting in an extremely complicated configuration and an increase in the scale of the device.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a space diversity device that can reliably achieve space diversity with a simple configuration.

[Means for solving problems]

In order to achieve the above object, the space diversity device of the present invention is mainly used in a space diversity device using a multicarrier modulation method that divides a band into a plurality of carrier waves and modulates each of the plurality of carrier waves to transmit a digital signal. A branch circuit that branches a signal received from an antenna into a signal for each carrier wave, a branch circuit that branches a signal received from a sub-antenna into a signal for each carrier wave, and a branch circuit that branches a signal received from an auxiliary antenna into a signal for each carrier wave, and a carrier wave signal from both branch circuits for each carrier wave. an in-phase combining circuit that takes in one carrier wave signal, passes it through an infinite phase shifter, combines it with the other carrier signal, removes the carrier wave with a bandpass filter after the combination, and controls the gain of the removed signal with an automatic gain control means; a control circuit that detects the automatic gain control voltage of the in-phase combining circuit for each of the carrier waves, and controls the phase of the infinite phase shifter of the carrier wave so that each of the automatic gain control voltages shows a maximum value. It is characterized by being prepared.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

1 and 2 are for detailed explanation of the present invention.

Here, FIG. 1 is a block diagram showing an embodiment of the space diversity device of the present invention. FIG. 2 is a block diagram showing an example of the configuration of a control circuit used in the same embodiment.

In FIG. 1, the received signal from antenna 1.2 can be fed to a receiver 3.4 with frequency conversion functionality. The receivers 3 and 4 are configured to receive local oscillation frequencies directly from the local oscillator 15, respectively.

Each output signal from each receiver 3, 4 is supplied to a branch circuit 6.7.
The output signal from the receiver 3 is converted into a signal S11 for each carrier wave.
+" ILS1ll. Furthermore, the branch circuit 7 divides the output signal from the receiver 4 into signals S II + S 11 + . . . for each carrier wave.
Is! It is now possible to branch to A. The signal S
II*S II-..., Sl.

and the signal S 1+ + 311 + . . .
, S21 are supplied to the in-phase synthesizing circuits 8+, 8g, . . . , 8n, respectively.
! +, and one carrier wave signal S! I is passed through an infinite phase shifter 81 and then combined with the other carrier signal S11 and a combiner 82.
After the combination, the carrier wave is removed by a bandpass filter 83, the removed signal is gain controlled by an automatic gain control means 84, and the bandpass filter i? 183 can be detected by a level detector 85 of the combined received signal. The in-phase synthesis circuits 8t, Bs, . . . 8° also have the same configuration as the in-phase synthesis circuit 81, except that the carrier waves handled are different. In-phase synthesis circuit 81.8z for each carrier wave, . . .
- Each output signal from each level detector 85, which is an automatic gain control voltage of 81, is respectively taken into the control circuit 9. The control circuit 9 is configured to be able to control the phase of the infinite phase shifter 81 of the carrier wave so that each of the automatic gain control voltages shows a maximum value.

The control circuit 9, as shown in FIG.
An analog-to-digital converter 91 that digitizes each output signal from 5, an input/output device (Ilo) 92 that takes in the signal from the analog-to-digital converter 91 and controls the phase of each infinite phase shifter 81, and 1092. It is composed of a CPU 93 that performs predetermined processing, and a memory 94 that stores predetermined processing procedures.

The operation of the embodiment configured as described above will be explained.

The received signal from the antenna 1.2 is fed to a receiver 3.4 with frequency conversion functionality. The receiver 3-4 converts the frequency of the received signal using the local oscillation frequency from the local oscillator 15 and outputs the result. In the 0 branch circuit 6, each output signal from each receiver 3.4 is supplied to a branch circuit 6.7, respectively.
The output signal from the receiver 3 is converted into a signal S II for each carrier wave.
+ S l! + . . . Branches to Sl. Further, the branch circuit 7 converts the output signal from the receiver 4 into signals S+u and Sz□ for each carrier wave.

...Branch to +St+b. Said signal S+t, S1□
,...S, and the signal St++Stx+...,
Sl means in-phase synthesis circuits 8+, 8m, . . . 8. are supplied respectively. In the in-phase combining circuit 81, the captured carrier wave signals S++, S□ are combined with the other carrier wave signal S11 by the combiner 82 after one carrier wave signal Sll passes through the infinite phase shifter 81. After the combination, the carrier wave is bandpass filtered. The removed signal is gain-controlled by an automatic gain control means 84, and the output from the bandpass filter 83 is detected by a level detector 85 of the combined received signal. In-phase synthesis circuit 8m, 83. . . 8 also operates in the same way as the in-phase synthesis circuit 81, except that the carrier waves handled are different. In-phase synthesis circuits S+, S*, ・ for each carrier wave
Each level detector 85 is an automatic gain control voltage of 81.
The respective output signals from the control circuit 9 are respectively given to the control circuit 9.

The control circuit 9 controls the phase of the infinite phase shifter 81 of the carrier wave so that each of the automatic gain control voltages shows a maximum value. That is, in the control circuit 9, each level detector 8
5 to the analog-to-digital converter 91rCP
Incorporate into U93. The CPU 93 compares the captured voltage with the detected voltage in the previous step stored in the memory 94, and determines the direction of the phase shifter 81 so that the detected voltage is maximized. Based on this determination by the CPU 93, the phase of each phase shifter 81 is controlled via l1092. The 11092 has a plurality of ports corresponding to each carrier wave, but internal processing is performed in a time-division manner.

In the above embodiment, the signal from the level detector 85 is used to improve the control speed, but the automatic gain control voltage of the automatic gain control means 84 may also be used.

〔Effect of the invention〕

As explained above, the present invention has the effect of reliably achieving space diversity for each carrier with a simple configuration by controlling the level detection signal after synthesis for each carrier using the control 'i1 circuit. .

[Brief explanation of drawings]

Figure 1 is a block diagram showing an embodiment of the present invention, and the second leap is a block diagram 1 showing the configuration of a control circuit used in the embodiment.
FIG. 3 is a block diagram showing a conventional device. 1.2...Antenna, 34...Receiver, 6.7...Branch circuit, 8,. 8. ,...,8゜...In-phase synthesis circuit, 9...
- Control circuit, 81... Phase shifter, 82... Synthesizer, 83... Bandpass filter, 84... Automatic gain control n means,

Claims (1)

[Claims] In a multi-carrier modulation space diversity device that divides a band into multiple carrier waves, modulates each of the multiple carrier waves, and transmits a digital signal, the received signal from the main antenna is branched into signals for each carrier wave. A branch circuit, a branch circuit that branches the received signal from the sub-antenna into a signal for each carrier wave, takes in carrier wave signals from both branch circuits for each carrier wave, passes one carrier signal through an infinite phase shifter, and then outputs it to the other carrier wave. an in-phase combining circuit that combines a carrier wave signal, removes the carrier wave with a bandpass filter after the combination, and controls the gain of the removed signal with an automatic gain control means; and an automatic gain control voltage of the in-phase combining circuit for each carrier wave. A space diversity device comprising: a control circuit that detects each of the carrier waves and controls the phase of the infinite phase shifter of the carrier wave so that each of the automatic gain control voltages shows a maximum value.