JPH01241203A - Digital beam forming device - Google Patents

Abstract

PURPOSE:To eliminate the need for an external device and to drastically improve the accuracy of calibration by adopting the constitution such that a false signal is fed to each reception unit and each reception unit uses an injected false signal to obtain a calibration signal. CONSTITUTION:A signal fR generated in a false signal generating section 10 is sent to each reception unit 7, in which the signal enters a switch 2. The switch 2 is thrown to the position C at the calibration, the signal fR enters a frequency converter 4 via a low noise amplifier 3, mixed with a signal from a local signal generator 9 and converted into an intermediate frequency fIF. The signal fIF is detected by a reception section 6, A/D-converted and fed to a digital beam forming device 8 as a calibration signal Ci. The forming device 8 processes calibration signals C0-Cn-1 sent from each reception unit and stores them as reference values. With the switch 2 thrown to the position S at the reception, reception signals S0-Sn-1 are inputted to the forming device 8, subjected to calculation processing as signals Si, Ci to form a beam.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital beamforming device, and particularly to an improvement in a calibration means for correcting variations in each receiving unit.

[Conventional technology]

Conventionally, there have been devices of this type, such as those shown in FIGS. 4 and 5, for example. In Figures 4 and 5, 1 is a receiver;
3 is an amplifier that amplifies the signal of the received signal frequency fR, 4 is a frequency converter, 5 is an intermediate frequency amplifier, 6 is a receiving section equipped with a wave detector and an A/D converter, 7 is a receiving unit that houses them, 8 is a digital beamformer that processes digital signals sent from a plurality of receiving units 7 and forms a beam; 9 is a local signal generator; 11 is a signal radiator with a reception signal frequency f; 10 is a reception signal This is one pseudo signal generator that generates a frequency.

Next, the operation will be explained. 1 A pseudo received signal of frequency f8 generated by the pseudo body signal generator 10 is emitted into space from the radiator 11, received by the receiver 1, amplified with low noise by the amplifier 3 of the receiving unit 7, and then sent to the frequency converter 4. It is mixed with a local signal of frequency fM flF sent from the local signal generator 9 and converted to an intermediate frequency flF. fl
The received signal converted to F is amplified by an intermediate frequency amplifier 5, detected by a receiving section 6, converted into a digital signal, and sent to a digital beamformer 8 as a calibration signal C4 (i=0 to n-1).
) is sent as

The digital beamformer 8 processes the calibration signal C6-cn-+ sent from each receiving unit and stores it as a reference value.

Next, when the original received signal fR3 is received, the signal sent to the digital beamformer 9 is 5o-sn-+
Then, by calculating with the reference value, S; −C+
If beam formation is performed with (i=0 to n-1), the variation in amplitude and one phase of each receiving unit is also corrected and beam formation is performed.

[Problem to be solved by the invention]

Conventional digital beamforming devices are configured as described above, so they require an external radiator, and the installation location cannot be moved freely, which poses considerable operational constraints. Also, the propagation loss and phase of the pseudo signal can easily change depending on weather conditions, so calibration is required @
There was a problem that accurate calibration could not be performed unless it was done frequently.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a digital beam forming device that can perform calibration without requiring an external device.

[Means to solve the problem]

The digital beam forming device according to the present invention includes:
A pseudo signal having the same frequency as the received signal is generated and sent to each receiving unit node, and a signal injection means injects the pseudo signal into each receiving unit.

[Effect]

In this invention, by configuring as described above, the pseudo No. 18 signal and the local signal are mixed in the receiving unit and converted to an intermediate frequency, and a calibration signal can be obtained. It becomes possible to perform calibration without being influenced by conditions.

〔Example〕

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

FIG. 1 shows a digital beamforming device according to an embodiment of the present invention, in which 1 is a receiver, 2 is a switch (signal injection means), 3 is a low noise amplifier, 4 is a frequency converter, and 5 is a receiver. is an intermediate frequency amplifier; 6 is a receiving section that performs wave detection and A/D conversion; 7 is a receiving unit in which these are housed; 8 is a receiving unit that processes digital signals from each receiving unit;
A digital beamformer forms a beam, 9 is a local signal generator, and 10 is a pseudo signal generator.

Next, the operation will be explained.

The fR signal generated by the pseudo signal generator 10 is sent to each receiving unit 7 and enters the switch 2. When calibrating switch 2,
The signal of fR is sent to the low noise amplifier 3, amplified, and enters the frequency converter 4, where it is mixed with the signal fRflF from the local signal generator 9 and converted to the intermediate frequency of f□. is converted to The signal converted to the intermediate frequency flF is detected by the receiving section 6, A/D converted, and sent to the digital beam former 8 as a calibration signal C1. The digital beamformer 8 processes the calibration signals C9 to cn-+ sent from each receiving unit and stores them as reference values. Next, when receiving, if the switch 2 is switched to the S side, the same processing is performed and the received signal S is sent to the digital beamformer 8. ~57-1 is input, and if the reference value and 5H-CH (i-〇~n-1) are processed and beam formed, the amplitude 2-phase variation of each receiving unit is also corrected and beam formation is performed. .

In the above embodiment, the switching device 2 is used, but a directional coupler 12 may be provided as shown in FIG.

In this case, no switching operation is required and the pseudo signal fR can be input at any time, so that part of the transmission time or part of the reception time can be used for calibration.

〔Effect of the invention〕

As described above, according to the digital beamforming device according to the present invention, the pseudo signal is sent to each receiving unit and each receiving unit uses the injected pseudo signal to obtain a calibration signal. It is not necessary and does not depend much on weather conditions (it has the effect of being able to perform calibration and greatly improving calibration accuracy).

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a receiving unit of a digital beamforming device according to an embodiment of the invention, FIG. 2 is a block diagram of the entire digital beamforming device of the invention, and FIG. 3 is another embodiment of the invention. A diagram showing
FIGS. 4 and 5 are block diagrams of the receiving unit and the entire conventional digital beamforming device. In the figure, 1 is a receiver, 2 is a switch (signal injection means)
, 4 is a frequency converter, 6 is a receiving section, 9 is a local signal generating section, 10 is a condensed signal generating section, and 12 is a directional coupler ((δ injection means). The same reference numerals in the figures are the same. - or a corresponding part. Agent Haya: 4n Constitution - Figure 1 Figure 3 12, f;

Claims (1)

[Claims] (1) A plurality of receivers each having a receiver for receiving a received signal, a frequency converter for mixing the received signal with a local signal and converting it into an intermediate frequency, and a receiving section for demodulating the intermediate frequency signal. A digital beamforming device comprising a receiving unit and a digital beamformer that stores a calibration signal and performs digital signal processing on this and a received signal of the receiving unit to correct variations in each receiving unit and form a beam, a pseudo signal generating section that generates a pseudo signal of the same frequency as the frequency of the received signal; and a pseudo signal generator provided between the receiver and the frequency converter in each receiving unit, converting the received signal or the pseudo signal into the frequency converter. a signal injection means for inputting the pseudo signal to the receiving unit, the digital beam forming apparatus comprising: a signal injection means for inputting the pseudo signal to the receiving unit;