JPH01223860A - Digital radio communication method - Google Patents

Abstract

PURPOSE:To eliminate the effect due to the fluctuation of amplitude, phase and frequency of an electromagnetic wave and to enhance ECCM performance by modulating digital information in the direction of polarization of a transmission electromagnetic wave and making communication while distinguishing the digital information depending on the polarization direction. CONSTITUTION:Digital information '1', '0' is modulated in the polarization direction of a transmission electromagnetic wave and the digital information is communicated while being distinguished depending on the polarization direction. For example, a carrier oscillator output is sent to positive, negative circularly polarized wave helical antennas 8, 9 in matching with '1', '0' of the digital data (serial) desired to be sent. On the other band, the signal received by the positive, negative circularly polarized wave helical antennas 47, 48 at the reception side is subjected to AM detection 45, 46 respectively, the level is compared by comparators 47, 48 and demodulated into '1', '0' serial digital data. In this case, since the output of the positive, negative circularly polarized wave helical antennas 41, 42 is inverted ASK output, the error bit is detected by taking the correlation of both. Then digital communication with noise immunity and high ECCM performance is always attained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a digital wireless communication method.

[Conventional technology] ASK is the current digital communication method.

There are FSK, PSK, DPSK, QPSK, and QAM, etc., and all of them are modulated by amplitude, frequency, phase, and a combination thereof, and polarization [Problem to be solved by the invention] of conventional digital wireless communication. In the modulation method, the transmitted information may be erroneous due to fluctuations in the amplitude, phase, and frequency of electromagnetic waves during propagation and external noise, and this is particularly noticeable in a strong ECM environment such as electronic warfare. Further, regarding error detection, troublesome procedures such as parity check are required. There is also the problem that if the receiving polarization direction does not match the transmitting polarization direction, the receiving sensitivity deteriorates significantly.

An object of the present invention is to provide a digital wireless communication method that can solve the above-mentioned conventional problems.

[Means for Solving the Problems] A digital wireless communication method according to the present invention includes digital information "1".

The present invention is characterized in that "0" is modulated in the polarization direction of the transmitted electromagnetic wave, and the digital information is communicated by distinguishing it by the polarization direction. For example, according to the present invention, digital information "1" and "0" can be distinguished by 18 circularly polarized waves (clockwise) and negative circularly polarized waves (counterclockwise), or two different constant Digital information "1" and "0" are distinguished and communicated in the polarization direction.

[Function] According to the present invention, by distinguishing digital information by the polarization direction, there is no influence from fluctuations in the amplitude, phase, and frequency of electromagnetic waves, and a filter with a narrower band can be used compared to FSX etc. ECCM performance is high because it can be Furthermore, since information from two different polarizations is correlated, errors can be easily detected. Furthermore, by adjusting the receiving antenna to match the polarization direction, sensitivity to external noise in the faith wave direction can be lowered.
Improves S/N. Conversely, if circularly polarized waves are used, there is no mismatch between the polarization directions of antennas on the transmitting and receiving sides (which occurs in moving objects such as aircraft and ships).

[Embodiment] FIGS. 1 to 3 are diagrams each showing an embodiment of the transmitting side of the present invention, and FIGS. 4 and 5 are diagrams each showing an embodiment of the receiving side of the present invention.

In FIG. 1, 1 is a carrier wave oscillator, 2 and 3 are IF switches, 4 and 5 are filters, 6 and 7 are power amplifiers, 8 is a positive circularly polarized helical antenna, 9 is a negative circularly polarized helical antenna, and 10 is a Inverter is shown.

In FIG. 2, 21 is a carrier wave oscillator, 22°23 is a multiplier, 24.25 is a filter, 26°27 is a power amplifier, 28 is a positive circularly polarized helical antenna, 29 is a negative circularly polarized helical antenna, and 30 is a negative circularly polarized helical antenna. Inverter is shown.

In Figure 3, 31 is a carrier wave oscillator, 32 is +90°
A phase shifter, 33 is a 90° phase shifter, 34 is a changeover switch,
35 is a filter, 36.37 is a power amplifier, and 38 is a cross typole antenna.

In FIG. 4, 41 is a circularly polarized helical antenna;
2 is a negative circularly polarized helical antenna, 43°44 is a filter, 45.46 is AM detection, 47°48 is a comparator,
49.50 indicates the reference voltage.

In FIG. 5, 51 is a cross dipole antenna;
2.53 is a filter, 54 is a phase difference detection, 55 is a comparator, and 56 is a reference voltage.

The transmitting side shown in FIG. 1 is for transmitting the output of a carrier wave oscillator by switching to positive and negative circularly polarized helical antennas 8 and 9 in accordance with "1" and "0" of digital data (serial) to be transmitted.

Figure 2 shows the product of each digital data to be transmitted with a carrier wave, and after removing unnecessary frequencies from the result using filters 24 and 25, positive and negative circularly polarized helical antennas 28
．． It is transmitted from No. 29.

In FIG. 3, digital data "1" is obtained by shifting the phase of the carrier wave by +90° and -90°.

0, and the output and carrier wave are applied to the horizontal and vertical directions of the cross dipole antenna 38, respectively, thereby modulating the waves into positive and negative circularly polarized waves, respectively, and transmitting them.

In addition, in Figures 1 and 2, if vertical and horizontal polarization antennas are used instead of the positive and negative circularly polarized helical antennas 8, 9, 28, 29, digital data "1" and "0" can be They can be replaced with vertical and horizontal polarization, respectively.

On the receiving side, in FIG. 4, after the signals received by the positive and negative circularly polarized helical antennas 41° and 42 are subjected to AM detection at 45° and 46,
The comparators 47 and 48 compare the levels and show “1” and “0”.
In this case, the outputs of the positive and negative circularly polarized helical antennas 41 and 42 are mutually inverted ASK outputs, so by correlating them, error bits can be detected. can be detected.

(ASK: Amplitude 5hift Ke
ying).

In Fig. 5, the vertical and horizontal components of circularly polarized waves are detected by a cross dipole antenna 51, and the phase difference (+90°, -90°) between them is obtained as a DC output and demodulated into serial digital data. .

[Effects of the Invention] According to the present invention, digital communication with high noise resistance and ECCM performance can be performed in any situation.

[Brief explanation of the drawing]

1 to 3 are block diagrams each showing an embodiment of the transmitting side used to implement the method of the present invention, and FIGS. 4 and 5 are block diagrams each showing an embodiment of the transmitter side used to implement the method of the present invention FIG. 2 is a block diagram showing an embodiment on the receiving side. 8.28.41...Circularly polarized helical antenna, 9.
29.42・Negative circularly polarized helical antenna, 38.51・
・Cross dipole antenna. Applicant's representative Patent attorney Takehiko Suzue Figure 5

Claims (1)

[Claims] In the digital wireless communication method, digital information "1",
A digital wireless communication method, characterized in that "0" is modulated in the polarization direction of transmission electromagnetic waves, and the digital information is communicated by distinguishing it by the polarization direction.