JPS59105727A - Space diversity receiving system containing anti-disturbance receiving function - Google Patents

Abstract

PURPOSE:To reduce as less as possible the rate incapable of communication by performing the reception for synthesization of space diversity maximum ratio in a normal case where a disturbance or interference wave can be ignored and then having the reception for deletion of disturbance wave in case an intensive disturbance or interference wave is applied. CONSTITUTION:The space diversity reception signals received by two space diversity antennas and converted into intermediate frequencies by a frequency converting circuit are supplied to input terminals IN-1 and In-2, respectively. The maximum ratio is synthesized by using intermediate frequency amplifiers 10 and 20 as a common AGC respectively after closing a changeover switch 50. The output Vm of an output terminal OUT-1 is turned into the maximum ratio synthesization output. The disturbance wave is deleted by using the amplifiers 10 and 20 as an independent AGC after opening the switch 50. The output Va of an output terminal OUT-2 is turned into a disturbance wave deletion output.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to a reception method for wireless communication, and in particular to space diversity maximum ratio combining.

Combine ) reception and W OOM (F:1e
ctric C! own-ter counter
This relates to a receiving system that has both measurement (anti-interference) reception functions.

[Description of prior art]

In wireless communication lines that require space diversity reception, if the presence of strong jamming waves or interference waves is expected, in addition to the space diversity combining function, a so-called ROOM function that actively removes the jamming waves is used. It is desirable to adopt a system that combines the two.

The conventional technology aimed at improving the damage intensity of this pair 1 (b) is approximately ■ (,: r3 (Spread E!
Communication method using RAM) technology ■ Adaptive Array
ay) is classified as a reception method using technology. Q) is a method of changing the communication system itself in order to increase the damage caused by UJJ, and although it is excellent in principle, it
1) It is difficult to apply because it requires extremely wide bandwidth compared to the M (hour-minute side multiplexing) method. (2) This is an attempt to adaptively remove interference waves by devising the C-passing method, and although it has its limitations, it is excellent in terms of practicality and economy.

Therefore, it is desirable to have a space diversity reception system that makes it possible to apply the adaptive array technology f: of (2), but such a reception system has not been known in the past.

[Object of the Invention] The purpose of the present invention is to perform space diversity maximum ratio combining reception in normal cases where jamming waves and interference waves can be ignored, and to perform interference wave cancellation when strong jamming waves and interference waves are added. It is an object of the present invention to provide an economical receiving method that reduces as much as possible the rate at which Fr cannot be traced during reception.

[Key points of the invention]

The present invention belongs to a reception method using adaptive array technology for anti-interference reception, and by extending the NuPace diversity maximum ratio combining reception method, anti-interference reception similar to adaptive array is possible. This is the reception method that was used.

The feature of the present invention is that the automatic gain control (AGO) of each receiving circuit amplifier can be switched between common AGC and independent AGO in the processing circuit for space diversity maximum ratio combined reception (2%). means and the (Th signal) of each diversity path added to an adder that combines each diversity signal in the same phase, and combines these signals so that interference waves are removed, and keeps the amplitude of the output constant. means, and performs anti-jamming reception by switching the common AGC to the independent AGC by the switching means.
The reason is that it is configured so that

[Explanation based on examples]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

The figure is a block diagram of a main signal processing circuit of a space diversity maximum ratio combining reception system with an ECCM function according to the present invention.

In the figure, the space diversity antenna, reception frequency conversion circuit, etc. are omitted, but the input terminal lN
Space diversity received signals received by two space diversity antennas and converted to an intermediate frequency by a frequency conversion circuit are input to input terminals -1 and IN-2, respectively.

1() and 2() are intermediate frequency amplifiers which output outputs V1 and 2, respectively. 11 and 2■ are respectively intermediate frequency amplifiers 10.20 AG (! (automatic gain control)
Amplifiers 12 and 22 are AGO amplifiers 11-j or 2
Either of 1 A G O'ji, AGO on the side with greater pressure
This diode constitutes an OR circuit for commonly applying the % pressure total intermediate frequency frequency intensifier IO and 20. 50 is AG
This is a changeover switch for operating the C amplifiers 11 and 21 as a common AGO or as an independent HAC, and when this changeover switch 50 is closed, it becomes a common AGO and space diversity maximum ratio combined reception is performed, and when it is opened, it becomes a common AGO and performs space diversity maximum ratio combined reception. Sometimes, the signal becomes independent A (i 0) and interference wave cancellation reception is performed.

13 and 23 are delay circuits, 14 and 24 are complex conjugate circuits, 15 and 25 are complex correlators, and 16 and 26 are low frequency F wave filters (LPFs).
．． 26 outputs an output "I+W2", 17 and 27 are complex four-quadrant multipliers, and 30 adds the outputs of the complex four-quadrant multipliers 17 and 27 to obtain an output v3 for maximum ratio combining reception. 31 is an intermediate frequency amplifier, which outputs the maximum ratio combined output vm to the output terminal 0UT-1. 32 is an AGC amplifier.

Further, 40 is a subtracter which takes the difference between the outputs of the complex four-quadrant multipliers 17 and 27 and outputs an output Vak for interference wave removal reception. Reference numeral 41 denotes an intermediate frequency amplifier, which outputs an interference wave removal output Va to the output terminal 0UT-2.

42 is an AGC amplifier.

The operating principle of this method is as follows.

The outputs v1 and v2 of the intermediate frequency amplifier 10.20 are considered to be the sum of the rare qJ waves S1 and S2 and the interference waves x1 and Xz, respectively, and if the thermal noise of received i'y ('iM is ignored as sufficiently small, then V+ =S+-1-XI (1
)V2= 82+X2 ・-= (
2). The maximum ratio synthesis operation, which assumes that the desired θ and Iuj harmful waves are uncorrelated, is performed by closing the selector switch 50 and making the intermediate frequency amplifiers 10 and 20 a common AGO, and the output terminal OUT -1 output ■. is its maximum ratio composite output.

When the desired wave is sufficiently large compared to the interference waves X1 and x2,
That is, in the case of Sl>XI, 82:>Xz, the output ■. is also 1vJf (waves become dominant,
Interference waves can be ignored. The amplitude Ilv, i of the output ■□ is 1 by the intermediate frequency amplifier 31 and the AC) O amplifier 32.
If normalized to Itonamiζ'=,';
The outputs W1 and W2 of 16 and 26 are w, =S111 = El,"...(
4) W2-82・1=62” ・・・・・・(
5) However, S1'' and S21 are numbers that are complex conjugates of Sl and S2, respectively.

becomes. Therefore, the output v5 of the adder 30 is Vs=
W1V1+W2V2=81'(F3+IX1)+S
2”(S2+X2)=(Sl”E!1 +82”82
)+(Sl”X1+82”Xz)・・・・・・(6
), which becomes the maximum dog ratio fj'x for the L desired wave.

Next, when the interference wave can no longer be ignored, correlation outputs related to the interference wave appear in w, , w2, so the maximum ratio synthesis for the desired signal in equation (6) is disturbed, and interference wave removal reception is interrupted. It becomes necessary.

The interference wave removal operation is performed by opening the changeover switch 50 and making the intermediate frequency amplifiers 10 and 20 independent AGOs, and the output va of the output terminal 0UT-2 becomes the interference wave removal output.

When the interference waves X,,X2 are large, that is, XI >
SI? When Xz > 82, interference waves are dominant on the output vm side, and desired waves can be ignored. At this time, the low frequency r wave generators 16 and 2
By analogy with the case of the maximum ratio combining operation described above, the outputs W1 and W2 of 6 are as follows in the steady state: w-=x・1=X,
' ・・・・・・(7)1 W2=X2・1=X2j ・・・・・・
(8) However, xl"X2'l are x, , x, respectively
It is a number that is complex conjugate to 2.

becomes. Therefore, the output v4 of the subtractor 40 is v4=
w, vl−w2v2=x,”(s,+x,)−4−(s
2+, x2) - (X, 'S+ - 2
0.21 performs AGC operation independently, so IX
, I=lX21, which becomes zero. This operation is similar to an adaptive array, and the intermediate frequency amplifier 1O12
The ratio of the desired wave and the interference wave of output V of 0 and v2 are equal, and the phase difference between the desired waves and the phase difference between the interference waves are equal,
In other words, it is shown that KOCM reception can be performed by removing the interfering waves except when the directions of arrival of the desired wave and the interfering wave are the same.

The above explanation has been about double space diversity, but by modifying the subtracter 40, it is possible to easily
Can be expanded to heavy space dipersina. Further, the switch J of the changeover switch 50 can be operated either manually or automatically.

〔Effect of the invention〕

As explained above, by using the receiving method of the present invention, space type diversity maximum ratio combining reception is performed in a wireless communication line that requires space diversity reception in normal times when jamming waves or interference waves can be ignored.
If the disturbance or interference waves can no longer be ignored,
Interference wave removal reception can be performed, and as a result, the rate of communication failure can be dramatically reduced compared to a reception method to which this method is not applied. In addition, this method uses FDM
-FM (Frequency Division Multiplexing/Frequency Modulation)
I) Applicable to M (time division multiplexing) system, F
71. It has excellent economic efficiency with less additional circuitry for CCM reception, and excellent stability because 1ltlJ ltl has positive feedback instead of negative feedback.
! It has length i.

[Brief explanation of drawings]

The figure is a block diagram showing the main signal processing circuit of the space diversity maximum ratio combining reception system with the civil 00M function according to the present invention. l0120.31.41...Intermediate frequency amplifier, 11.
21, 32.42...A GO amplifier, 14.2
4...Complex conjugate circuit, 17.27...Complex 4-quadrant multiplier, 30...Adder, 40...Subtractor, 50...
・Selector switch. Procedural Amendment I, Indication of Case Patent Application No. 216640 of 1982, Title of Invention Space Daihashi Receiving System with Ih Anti-Interference Reception Function % Type % Name (423) Tadahiro Sekimoto, Representative of NEC Corporation 4, agent 5, 1 koi of 1iti positive command = 1 (spontaneous correction)
6. Number of inventions increased by amendment None 7. Subject of amendment

Claims (1)

[Claims] (Multiple receivers (i) for performing space diversity
A space diversity signal is obtained by automatically controlling common gain of the amplifiers of the plurality of receiving means to obtain a diversity signal from each receiving means, and combining the diversity signals in phase with the combining means. In a receiving system that performs maximum ratio combining, switching between a mode in which the automatic gain control of the amplifiers of each receiving means is performed by common control and a mode in which each receiving means is performed by a single independent control unit 11. With means. ”Each diversity added to the secondary hk means (
and a second combining means that branches the Q signal and combines these diversity signals so that the interference wave is removed, and when the level of the interference wave is large, the above-mentioned J alarm means performs gain control entirely independently. An Etaspace diversity reception system equipped with an anti-jamming reception function, characterized in that it is configured to be able to switch between modes.