KR100867075B1 - Cross polarization transmission method - Google Patents

Abstract

MPEG TS of separate information is input in vertical and horizontal polarization, and null insertion processing is provided in each system of horizontal and vertical polarization to equalize TS rates, and common clock and preamble period timing pulses are synchronized in time. Let's do it.

The reference signal performs transmission in the form of the first half of the preamble period with only horizontal polarization and the second half with only vertical polarization, and the equalization processing of the reception is performed in the first half of the horizontal polarization and the second half of the vertical polarization. do.

Alternatively, the frequency is half offset to negate the crosstalk of the horizontal polarization and the vertical polarization, which are added once every preamble period and inverted once. In addition, mutual crosstalk is calculated by subtracting the signal delayed in the preamble period.

After mutual crosstalk is subtracted from the opponent's decoding signal, it is equalized, demodulated, error-corrected and decoded, and TS is output.

Description

Cross polarization transmission method {CROSS POLARIZATION TRANSMISSION METHOD}

The present invention relates to a transmission device for performing digital modulation demodulation for digitally transmitting an image or data.

Although video and audio have been transmitted by analog FM a few years ago for wireless transmission of video and audio signals, a digital transmission scheme such as a quadrature amplitude modulation (QAM) scheme has recently been used.

Television broadcasts send to the headquarters microwaves the broadcast material received at the top of a mountain or in a tall building (most often with a transmitting station). A transmitter that connects video or audio from the transmitter to the studio is called TSL. This TSL device is an important line for transmitting to a general home, and is composed of a control unit for modulating, a high frequency unit for converting into microwaves, a power supply, and the like.

In view of the effective use of radio resources these days, it is desired to transmit separate materials at the same frequency. A representative example is the method of transmitting material 1 as horizontal polarization and material 2 as vertical polarization.

Fig. 9 is a block diagram showing the overall configuration of a TSL device using horizontal (H) and vertical (V) polarizations in a conventional video transmission system. The video is digital data in the TS (Transport Stream) format of MPEG and is input to the transmission control units TCs 5a and 5b. The TC performs a single 64 QAM modulation and outputs an 130 MHz IF signal. The IF signal is sent to the transmitting high frequency units TH (2a, 2b), converted into a signal of the microwave band and performs power amplification, and is output from the antenna 6 in horizontal polarization and vertical polarization, respectively. A single QAM signal in microwave reaches the studio's receiving antenna (7) several kilometers to tens of kilometers away. As for the signal from the antenna 7, the H component and the V component are respectively taken out and input to the reception high frequency units (RH) 9a, 9b. The RHs 9a and 9b convert the received single QAM signal into a 130 MHz IF signal and hand it to the reception control units RC 8a and 8b. The video data TS demodulated by the RCs 8a and 8b is output.

10 is a block diagram showing the configuration of a TC of a conventional digital TSL device using horizontal and vertical polarization. TS input data is received by an external encoder 12 with a parity signal. The phase locked voltage controlled oscillator (PLLVCO) 18 receives a system clock sys-ck and sends a clock CK of a predetermined frequency to each part. The control unit CONT 15 receives the CK, and passes the control signal to H in the preamble period to the preamble pattern generator 14 and the selection unit SEL 16. TS input data receiving the parity signal is time-compressed via the memory 13 except for the preamble period, the preamble is inserted in the SEL 16, and a single 64 QAM modulation is performed in the MOD 17. Is converted into an IF signal of MHz. The role of the preamble is used on the receiving side to determine sample timing of subsequent data symbols and to correct waveform distortion caused by transmission.

Although the transmission high frequency parts 2a and 2b are basically the same structure, time delay etc. are slightly different from the difference in the detailed characteristic of a microwave band filter etc.

Fig. 11 is a block diagram showing the RC configuration of a conventional TSL device using horizontal and vertical polarization, and Fig. 12 is a block showing the detailed configuration of a RC demodulation unit (DEM) of a conventional TSL device using horizontal and vertical polarization. FIG. 13 is a transmission / reception timing diagram illustrating a signal type of a conventional TSL.

[Patent Document 1]

Japanese Patent Laid-Open Publication Pyeongseong 10-17579

[Patent Document 2]

Japanese Patent Laid-Open No. 2004-201154

In the conventional configuration described above, the horizontal polarization and the vertical polarization usually generate cross talk of 15 dB to 25 dB or less. In addition, when the propagation state fluctuates, there is a case in which crosstalk is increased. In this case, since the vertical polarization and the horizontal polarization transmit different materials, the transmitted contents are different and affect each other as noise.

An object of the present invention is to realize a transmission system capable of attenuating crosstalk of horizontal and vertical polarizations in a system for removing these defects and transmitting separate materials in horizontal and vertical polarizations.

To solve the above problems, the present invention transmits each system of horizontal polarization and vertical polarization synchronously, and offsets a predetermined half of the horizontal and vertical polarizations from a predetermined axis.

Specifically, in the digital transmission method for transmitting each piece of information using horizontal and vertical polarizations, each system of horizontal and vertical polarizations is transmitted in synchronism with time, and for a predetermined period on the time axis in horizontal and vertical polarizations. Is divided into half and offset by half of a predetermined period or by half frequency of a predetermined frequency.

More specifically, in a digital transmission method for transmitting information using horizontal and vertical polarization, each system of horizontal and vertical polarization is transmitted in synchronization in time, and the reference signal is divided into preamble periods. The other side which has only horizontal polarization and divides the preamble period transmits a transmission signal having a configuration in which only vertical polarization exists.

In the above digital transmission method, the equalization processing of reception is performed by horizontal polarization on one side of the preamble period and vertical polarization on the other side of the preamble period, and from horizontal polarization to vertical polarization on one side of the preamble period. Crosstalk is detected, the crosstalk from the vertical polarization to the horizontal polarization is detected on the other side where the preamble period is divided, the crosstalk portion is calculated from the decoding result, and the crosstalk portion is subtracted from the opponent's decoding signal. .

More specifically, it has a digital modulator and a digital demodulator of a plurality of systems of horizontal polarization and vertical polarization, and each system of horizontal polarization and vertical polarization transmits synchronously in time, and the reference signal is only horizontal polarization in the first half of the preamble period. In the second half, only the vertical polarization is transmitted, and the equalization processing of the reception is performed in the first half of the horizontal polarization and the second half of the vertical polarization. In the first half, the crosstalk from the horizontal polarization to the vertical polarization is detected. The crosstalk portion of the horizontal polarized wave is detected, the crosstalk portion is calculated from the decoding result, the crosstalk portion is subtracted from the opponent's decoding signal before demodulation and error corrected and decoded. Alternatively, the reference signal is transmitted in the form of the first half only and the second half only horizontally polarized. The equalization processing of the reception is performed in the first half and the horizontal one in the second half. The crosstalk portion of the furnace is detected, the crosstalk portion from the horizontal polarization to the vertical polarization is detected in the second half, the crosstalk portion is calculated from the decoding result, and the demodulation is performed after subtracting the crosstalk portion from the opponent's decoding signal. Error correction and decoding.

In the above-described transmission method, separate information is transmitted in the horizontal and vertical polarizations, and the transmitting side commons the clock and the preamble period pulses in each of the horizontal and vertical polarizations.

In the above transmission method, digital data in the TS (Transport Stream) format of MPEG is transmitted, a null insertion process is provided on the transmission side, and TS rates are equalized in horizontal and vertical polarizations.

In a digital transmission method for transmitting respective information using horizontal and vertical polarizations, each system of horizontal and vertical polarizations is synchronized in time, and one polarized wave is inverse of the preamble period with respect to the other polarized wave. It transmits by offsetting to either frequency of half frequency or half frequency of carrier spacing frequency.

Further, in the digital transmission method described above, cross-talk between horizontal and vertical polarizations is performed by offsetting and transmitting at a frequency half of the inverse of the preamble period, and equalizing the reception by adding the preamble period evenly and inverting each time. Deny minutes, subtract one cycle to subtract their components, negate their crosstalks, calculate crosstalks of horizontal and vertical polarizations, and subtract crosstalks from their decoded signals.

Further, in the above-described transmission method, the equalization processing of reception decodes the crosstalk portion from the opponent's decoded signal before equalizing, demodulating and error correcting and decoding.

In the above-described transmission method, single QAM modulation is used to transmit at a frequency different from about 357 kHz of half the frequency of the reciprocal of the preamble period of about 1.4 ms.

In the above digital transmission method, OFDM modulation is used to offset one polarized wave at a frequency half of the carrier interval frequency with respect to the other polarized wave.

In addition, in the above-described transmission method, separate information is transmitted in the horizontal and vertical polarizations, and the transmission side commonizes the clock and preamble period timing pulses and the reference frequency in the high frequency unit in each of the horizontal and vertical polarizations.

As described above, according to the present invention, since the clock and the preamble period timing pulses are common, the TS rate is equalized by null insertion, and time synchronization is performed, it is possible to stably cross the horizontal polarization to the vertical polarization throughout the preamble period. The torque component can be detected, and the crosstalk component from the vertical polarization to the horizontal polarization can be detected later in the preamble period, and the crosstalk component can be attenuated with high accuracy. As a result, signal degradation can be suppressed as well as error correction, so that separate materials can be transmitted stably at the same frequency.

Alternatively, the clock and preamble period timing pulses are common, the TS rate is equalized by null insertion, and time synchronization is performed. Therefore, the horizontal cross and the vertical polarization cross each other are steadily added by adding the preamble period stably. The torque can be negated. In addition, mutual crosstalk portions can be detected stably, and crosstalk portions remaining in a negative state can be corrected with high accuracy. As a result, signal degradation can be suppressed as well as error correction, so that separate materials can be transmitted stably at the same frequency.

In the case of OFDM modulation, since the signal offset up or down by half the frequency of the carrier spacing appears as noise, self-equalization is not affected by mutual crosstalk.

The configuration and basic operation of one embodiment according to the present invention will be described with reference to Figs. 1 to 8, and the configuration and basic operation of another embodiment will be described with reference to Figs. 18 to 23, 5 and 6, and Figs. It demonstrates using 17.

1 is a block diagram showing the overall configuration of an image transmission system according to an embodiment of the present invention. In the block diagram showing the overall configuration of the conventional video transmission system of FIG. 9, the main difference of FIG. 1 is that on the transmitting side, the common clock t-ck and t pulses of the transmission preamble period are supplied from the control unit 3C to the transmission control unit TC. Synchronous processing by stuffing and alternating pause of the reference signal are performed. On the receiving side, the crosstalk coefficient s is returned from the reception control unit RC to the control unit 4C. When the crosstalk coefficient s is larger than a predetermined amount, the control unit 4C instructs the subtraction control FC to the RC to control the subtraction of the counterpart crosstalk component by ON.

In Fig. 1 of the block diagram showing the overall configuration of an image transmission system according to an embodiment of the present invention, 1a and 1b are the transmission control unit TC, 2a and 2b are the transmission high frequency unit TH, 3c and 4c are the control unit CONT. ), 6 and 7 are antennas, 9a and 9b are reception high frequency units (RH), and 10a and 10b are reception control units (RC).

Fig. 5 is a block diagram showing a transmission control section TC of one embodiment of the present invention, and Fig. 6 is a block diagram showing details of the stuffing section 11 of TC of one embodiment of the present invention. 5 and 6, the TS input is read from the memory 33 in accordance with the common clock t-ck, so that the shortage of the amount of data being stored is eliminated. It outputs as a full / empty signal, and when null is generated in the null inserting section 35, a null is inserted. If a pool is generated, NULL is deleted and the uniformity TS is matched to the read rate. The homogenized TS receives a parity signal in the external encoder 12. The control unit CONT 15 receives the common clock t-ck, and passes the control signal H to the preamble pattern generator 14 and the selection unit SEL 16 in the preamble period. The TS input data to which the parity signal is added are time-compressed via the memory 13 except for the preamble period, the preamble is inserted in the SEL 16, and the single modulator (MOD) 17 performs single 64QAM modulation. And a 130 MHz IF signal.

2 is a timing diagram of the transmission side of the present invention in one embodiment, and FIG. 3 is a timing diagram of the reception side in the first embodiment of the present invention, and a difference from FIG. 13 in the transmission / reception timing diagram showing a conventional signal form is an IF signal. There is an idle period of the reference signal alternately in the first and second half of the preamble period. Using this rest period, the crosstalk component from the horizontally polarized wave to the vertically polarized wave (V component) is detected in the first half, and the crosstalk component from the vertically polarized wave to the horizontally polarized wave (H component) in the second half.

4 is a schematic diagram showing a receiving side process according to an embodiment of the present invention, FIG. 7 is a block diagram showing a receiving control unit RC according to an embodiment of the present invention, and FIG. 8 is a demodulation unit of RC according to an embodiment of the present invention. It is a block diagram which shows (DEM). 4, 7, and 8, the horizontally polarized wave data Dc1 generated by demodulating IFr1 is remodulated to generate a horizontally polarized wave modulation waveform Hm, and the horizontally polarized wave crosstalk is generated in the crosstalk component generation process. Generate waveform Hs. Similarly, the vertical polarization (V) data (Dc2) generated by demodulating IF2r is remodulated to generate a vertical polarization (V) modulation waveform (Vm), and the vertical polarization (V) crosstalk waveform in the crosstalk component generation process. Produces (Vs). Subtract Vs from IFr1 and then equalize and demodulate to H data Dc1 and correct the error to reproduce horizontal polarization (H) TS, subtract Hs from IFr2, then equalize and demodulate V The data Dc2 is used and the error is corrected to reproduce the vertical polarized wave (V) TS.

In Fig. 8 of the block diagram showing the RC demodulation section (DEM) of one embodiment of the present invention, 21a and 21b are re-modulation sections, 22a and 22b are coefficient multipliers, 23a and 23b are gate on / off, 24a and 24b. Are subtractors, 25a and 25b are equalizers, 26a and 26b are demodulators, 27a and 27b are preamble extractors, 28a and 28b are equalization calculators, and 29a and 29b are crosstalk detectors. In Fig. 8, the V data Dc2 becomes the V modulated waveform Vm in the remodulation section 21a, and Vm is multiplied by the crosstalk coefficient s1 in the coefficient multiplying section 22a, and the subtraction control FC1 at the gate on / off 23a. Is controlled to become V crosstalk waveform Vs. From the IFr1, the preamble extractor 27a generates Pr-puls and the sustain instruction pulse of the received preamble period pulses, and the equivalent calculator 28a and the crosstalk detector 29a generate the crosstalk coefficient s1. Similarly, crosstalk coefficient s2 is generated from IFr2.

In the above, the reference signal has been described in such a manner that only the horizontal polarization is present in the first half of the preamble period and only the vertical polarization is present in the second half. Similarly, even if the reference signal transmits only the first half of the vertical polarization and only the second half of the horizontal polarization, the equalization processing of the reception is performed in the first half of the vertical polarization and the second half of the horizontal polarization. Detects minutes, detects crosstalk from horizontal to vertical polarization in the second half, calculates crosstalk from the decoding result, subtracts the crosstalk from the opponent's decoding signal, equalizes and demodulates, and corrects errors. Decoding and outputting TS. In general, even if the reference signal is transmitted with only one horizontally polarized wave divided by the preamble period and only the vertically polarized wave with the other divided by the preamble period, the equalization processing of the reception is similarly performed by the horizontal polarized wave, one of which divided the preamble period arbitrarily. The vertical polarization is performed on the other side of the preamble period, and the crosstalk portion from the horizontal polarization to the vertical polarization is detected on one side of the arbitrary division of the preamble period, and the vertical polarization to the horizontal polarization on the other side of the preamble period. It is possible to detect the crosstalk component, calculate the crosstalk component from the decoding result, subtract the crosstalk component from the opponent's decoding signal, equalize, demodulate, error correct, decode, and output the TS.

18 is a block diagram showing the overall configuration of an image transmission system according to another embodiment of the present invention. In the block diagram showing the overall configuration of the conventional video transmission system of FIG. 9, the main difference of FIG. 18 is that the common clock t-ck and t-puls of the preamble period are supplied from the control section 3C to the transmission control section TC on the transmitting side. Synchronization processing by stuffing and alternating pause of the reference signal are executed, and the reference frequency fr is supplied from the frequency reference transmitter (XO) 36 to the transmitting high frequency unit TH. On the receiving side, the common clock t-ck and t-puls of the preamble period are supplied from the control section 4C to the preprocessing section, and the crosstalk coefficient s is returned from the reception control section RC to the control section 4C. When the crosstalk coefficient s is larger than a certain amount, the control unit 4C instructs RC to the subtraction control FC a process of controlling ON and subtracting the subtraction of the counterpart crosstalk.

In FIG. 18 of a block diagram showing the overall configuration of an image transmission system according to another embodiment of the present invention, 1a and 1b are the transmission control unit TC, 2a and 2b are the transmission high frequency unit TH, and 3c and 4c are the control unit ( CONT), 6 and 7 are antennas, 9a and 9b are reception high frequency units (RH), 40a and 40b are preprocessing units, and 10a and 10b are reception control units RC. The preprocessors 40a and 40b will be described in detail later with reference to FIGS. 14 and 15.

The predetermined reference frequency fr is commonly supplied from the frequency reference transmitter (XO) 36 to the high frequency units TH1 and TH2. TH1 and TH2 are based on a reference frequency, for example, TH1 is 6999.643 MHz and TH2 is 7000 MHz. Or TH1 is 7000.357 MHz and TH2 is 7000 MHz.

19 is a transmission side timing diagram according to another embodiment of the present invention, and FIG. 20 is a reception side timing diagram according to another embodiment of the present invention. The difference from FIG. 13 in the transmission / reception timing diagram showing the conventional signal form is that the frequency of the IF signal is +357 Hz or -357 Hz frequency offset, which is half the reciprocal of the preamble period. By using this frequency offset, the mutual crosstalk between the horizontal and vertical polarizations which are inverted once by adding the preamble period evenly can be negated. In addition, the crosstalk portion can be detected stably, and the crosstalk portion remaining in a negative state can be accurately corrected.

Fig. 21 is a schematic diagram showing a receiving side processing of another embodiment of the present invention, Fig. 22 is a block diagram showing a receiving control unit RC according to another embodiment of the present invention, and Fig. 23 is a RC of another embodiment of the present invention. Is a block diagram showing a demodulation section DEM. 21, 22, and 23, the horizontally polarized wave (H) data Dc1 generated by demodulating IFr1 is remodulated to generate a horizontally polarized wave modulation waveform (Hm), and the horizontally polarized wave crosstalk is generated in the crosstalk component generation process. Generate waveform Hs. Similarly, the vertically polarized wave data (Dc2) generated by demodulating IF2r is remodulated to generate a vertically polarized wave modulation waveform (Vm), and a vertically polarized crosstalk waveform (Vs) is generated in the crosstalk component generation process. . Subtract Vs from IFp1, then equalize and demodulate to Dc1, and correct the error to reproduce horizontal polarization (H) TS, subtract Hs from IFp2, then equalize and demodulate to reproduce vertical polarization (V) TS do.

In FIG. 23 of a block diagram showing a RC demodulation unit (DEM) of another embodiment of the present invention, 21a and 21b are remodulation units, 22a and 22b are coefficient multipliers, 23a and 23b are gate on / off, 24a, 24b is a subtractor, 25a and 25b are equivalent parts, 26a and 26b are demodulators, 27a and 27b are preamble extractors, 28a and 28b are equivalent calculators, and 29a and 29b are crosstalk detectors. In Fig. 23, the V data Dc2 becomes the V modulation waveform Vm in the remodulation section 21a, and Vm is multiplied by the crosstalk coefficient s1 in the coefficient multiplier 22a, and the subtraction control FC1 in the gate on / off 23a. Is controlled to become V crosstalk waveform Vs. From the IFp1, the preamble extractor 27a generates Pr-puls of the received preamble period pulse. The crosstalk coefficient s1 is generated by the crosstalk detection unit 29a from IFb1 and IFr1. Similarly, crosstalk coefficient s2 is generated from IFb2 and IFr2.

14 is a block diagram showing a preprocessing unit for reception according to another embodiment of the present invention, FIG. 15 is a timing diagram showing the operation of the preprocessor unit for reception according to another embodiment of the present invention, and FIG. 17 is a block diagram showing a reception crosstalk detection unit according to another embodiment, and FIG. 17 is a timing diagram showing the operation of the reception crosstalk detection unit according to another embodiment of the present invention. 14 and 15, the delay unit 37a of the preprocessing unit 1 sets IFr1 to IFb1 by delaying the preamble period. The adder 38a adds IFr1 and IFb1 to reproduce the reference signal. Based on the t-puls of the preamble period pulse of the SEL 39a, a reference signal is selected in the preamble period, IFr1 is selected in the data period, and IFp1 is generated.

16 and 17, the subtractor 41a of the crosstalk detection unit subtracts IFb1 delayed by the preamble period from IFr1. IFb1 from 40a of preprocessing unit 1 may be used as shown in FIG. 16 (a), or IFr1 may be used as IFb1 by delaying preamble period in delay unit 40a of crosstalk detection unit 29a as shown in FIG. good.

The above description is an example of a single QAM, but in OFDM, it is also possible to use a frequency offset of half the carrier interval frequency. In the case of OFDM modulation, since the signal offset up or down by half the frequency of the carrier spacing appears as noise, self-equalization is not affected by mutual crosstalk.

In addition, in the above, the case of transmitting separate information in the horizontal and vertical polarization has been described. Similarly, in the case of diversity transmitting the same information in horizontal and vertical polarization, mutual crosstalk is calculated, and mutual crosstalk is subtracted from the opponent's decoded signal, equalized, demodulated, and error corrected and decoded. It is possible to output the TS and to make it stronger against degradation of the transmission path state.

1 is a block diagram showing the overall configuration of an image transmission system according to an embodiment of the present invention.

Fig. 2 is a transmission timing diagram showing a signal form of one embodiment of the present invention.

Fig. 3 is a reception timing diagram showing a signal form of one embodiment of the present invention.

4 is a schematic diagram showing a receiving side process according to an embodiment of the present invention.

Fig. 5 is a block diagram showing a transmission control unit TC in one embodiment of the present invention.

Fig. 6 is a block diagram showing a stuffing portion of a TC of one embodiment of the present invention.

7 is a block diagram showing a reception control unit RC according to an embodiment of the present invention.

Fig. 8 is a block diagram showing a demodulation unit (DEM) of RC of one embodiment of the present invention.

9 is a block diagram showing the overall configuration of a conventional video transmission system.

10 is a block diagram showing a conventional transmission control unit TC.

11 is a block diagram showing a conventional reception control unit RC.

12 is a block diagram showing a demodulation unit (DEM) of a conventional RC.

13 is a transmission and reception timing diagram showing a conventional signal type.

Fig. 14 is a block diagram showing a pre-receiving processing section according to another embodiment of the present invention.

Fig. 15 is a timing chart showing the operation of the pre-receiving processing section according to another embodiment of the present invention.

Fig. 16 is a block diagram showing a receiving crosstalk detection unit according to another embodiment of the present invention.

Fig. 17 is a timing chart showing the operation of the reception crosstalk detection unit according to another embodiment of the present invention.

18 is a block diagram showing the overall configuration of an image transmission system according to another embodiment of the present invention.

Fig. 19 is a transmission side timing diagram showing a signal form (frequency offset and yin and yang of each waveform) according to another embodiment of the present invention.

20 is a timing diagram showing a reception side showing a signal form according to another embodiment of the present invention;

Fig. 21 is a schematic diagram showing the receiving side processing of another embodiment of the present invention.

Fig. 22 is a block diagram showing a reception control unit RC according to another embodiment of the present invention.

Fig. 23 is a block diagram showing a demodulation unit (DEM) of RC according to another embodiment of the present invention.

Claims (11)

delete delete In the digital transmission method for transmitting each piece of information using horizontal and vertical polarization, Each system of the horizontal polarization and the vertical polarization transmits synchronously in time, and the reference signal is a signal configuration in which only one horizontal division is divided by the preamble period and only the vertical polarization is present by the other division of the preamble period. Characterized in that for transmitting a signal Digital transmission method. In the digital transmission method of claim 3, The equalization processing of the reception is performed such that the horizontal polarization is performed on the one side that divides the preamble period, the vertical polarization is on the other side that divides the preamble period, and the vertical polarization from the horizontal polarization on one side that divides the preamble period. Crosstalk from the vertical polarized wave to the horizontal polarized wave on the other side of the preamble period, and subtracting the crosstalk portion from the opponent's decoded signal. Digital transmission method. In the transmission method of Claim 3 to 4, Separate information is transmitted in the horizontal polarization and the vertical polarization, and the transmitting side commons a clock and a preamble period pulse in each system of the horizontal polarization and the vertical polarization. Transmission method. In the transmission method of Claim 3 to 4, It is characterized by transmitting digital data in TS (Transport Stream) format of MPEG, providing null insertion processing on the transmitting side, and equalizing TS rates in the horizontal polarization and the vertical polarization. Transmission method. In the digital transmission method for transmitting each piece of information using horizontal and vertical polarization, Each system of the horizontal polarization and the vertical polarization is synchronized in time, and the polarization of one of the horizontal polarization and the vertical polarization is half the frequency of the reciprocal of the preamble period with respect to the other polarization other than the one polarization or Characterized in that the transmission is offset to any one of the frequencies of half the carrier interval frequency  Digital transmission method. In the digital transmission method of claim 7, The transmission is offset by a frequency half of the inverse of the preamble period, and the equalization processing of the reception adds the even number of the preamble periods, erases the crosstalk of the horizontal and vertical polarizations to be inverted once, and delays one period to subtract. And erasing its own component to calculate the mutual crosstalk of the horizontal and vertical polarizations, and subtracting the mutual crosstalk from the decoded signal of the opponent. 8. The transmission method according to claim 7, characterized in that the transmission is offset by a frequency different from about 357 kHz, which is half the frequency of the reciprocal of the preamble period of about 1.4 ms using single QAM modulation.  Digital transmission method. A digital transmission method according to claim 7, wherein the OFDM polarization is transmitted by offsetting the one polarized wave at a frequency half of a carrier interval frequency with respect to the other polarized wave. Digital transmission method. In the digital transmission method of claim 7 to 10, Separate information is transmitted in the horizontal polarization and the vertical polarization, and the transmitting side commons a clock, a preamble period timing pulse and a reference frequency of the high frequency part in each of the horizontal polarization and the vertical polarization.  Digital transmission method.

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