JP4243726B2 - Communication device - Google Patents

Description

  The present invention relates to a communication device that transmits and receives digital data, and more particularly to a digital signal transmission system.

  For example, a conventional communication apparatus may include a “frequency monitoring means for monitoring the appearance frequency of data in an input digital signal, and a first modulation pulse width based on the appearance frequency monitored by the frequency monitoring means. And assigning a second modulation pulse width longer than the first modulation pulse width to the second data having a lower frequency of appearance than the first data, and pulse width modulation for pulse-width modulating the input digital signal And a data modulation system characterized by comprising the above-mentioned means "(for example, see Patent Document 1).

Japanese Patent Laid-Open No. 9-246973 (Claim 4, FIGS. 1 and 5)

  The transmission method of the conventional communication apparatus uses a means such as a heterodyne method in which a carrier frequency signal is generated in a receiving unit and a received signal is multiplied to form a baseband in order to separate a noise signal and a carrier signal. In addition, since a transmitter having a frequency matching the transmission-side carrier frequency is required in the receiving unit, and a transmitter with high frequency accuracy is required, there is a problem that the circuit scale is increased and the cost is increased.

  In addition, when the receiving circuit is configured by using an LC tuning circuit to reduce the cost, since the tuning circuit has a resonance point at the carrier signal frequency, the received signal energy causes a damped oscillation in the tuning circuit, and the carrier There is a problem that waveform distortion occurs due to continued vibration even after the stop, and there is a high possibility that a reading error will occur due to overlapping with the next data bit, so that reliable transmission cannot be realized.

  The present invention has been made to solve such a problem, and provides a communication device that can realize a low-cost and highly reliable communication method.

The communication apparatus according to the present invention includes a communication control means for encoding a logical value of digital data with a pulse train of a pulse width modulation signal (hereinafter referred to as a PWM signal) composed of a plurality of pulses having different duty ratios, and a pulse train of the PWM signal. A modulation unit that modulates the transmission signal; and a transmission unit that transmits the transmission signal . The communication control unit includes a first duty that is a predetermined duty ratio and a second duty that is lower than the first duty. Are encoded with a first logical value, which is a logical value of digital data, by using a first pulse train of a pulse width modulation signal composed of a pulse train obtained by combining one or more of the above and the pulse train of either the first duty or the second duty The second logical value, which is the logical value of the digital data, is encoded by the second pulse train of the pulse width modulation signal comprising:

  The present invention can reduce digital data reading errors by encoding the logical value of digital data to be transmitted with pulses of a plurality of PWM signals having different duty ratios.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a communication system according to Embodiment 1 of the present invention. In FIG. 1, a plurality of communication devices 1 are arranged, and each communication device 1 is connected to each other by a wireless medium 2 using radio waves to perform data communication.

FIG. 2 is a diagram showing the configuration of the communication apparatus according to Embodiment 1 of the present invention. In FIG. 2, a tuning circuit unit 3 serving as a receiving means is a tuning circuit having a resonance point at a predetermined carrier frequency, and receives an amplitude-modulated transmission signal. The reception amplifier 4 amplifies the reception signal selectively received by the tuning circuit unit 3 to a predetermined voltage level. The time constant of the tuning circuit of the tuning circuit unit 3 is set to be shorter than a pulse period tp-tw2 of a PWM signal to be described later with the input impedance of the receiving amplifier 4 as a load resistance.
The detector 5 is composed of a low-pass filter circuit (hereinafter referred to as LPF) using a diode, a resistor, and a capacitor. The cutoff frequency of the LPF is set lower than the carrier frequency, and the received signal amplified by the receiving amplifier 4 is received. It operates so as to be converted into a direct current by a diode and further remove a carrier frequency component. The comparator 6 binarizes the signal output from the detection unit 5. The detection unit 5 and the comparator 6 constitute detection means for demodulating the amplitude-modulated received signal. The communication control means 7 is constituted by a microcomputer or the like, and receives a demodulated reception signal.

The amplitude modulation circuit unit 8 as modulation means is composed of a carrier signal generation circuit and an AND circuit. The data signal to be transmitted is input from the communication control means 7 to the amplitude modulation circuit unit 8 and is amplitude-modulated at a predetermined carrier frequency to generate a transmission signal. The transmission amplifier 9 amplifies the transmission signal to a predetermined signal power, inputs it to the tuning circuit unit 3 that is a transmission means, and transmits the signal as a radio wave.
A transmission system in which digital data is transmitted and received by a PWM signal with such a configuration will be described next.

FIG. 3 is a diagram illustrating a conventional data transmission / reception method using a PWM signal. As shown in FIG. 3, the conventional transmission / reception of data using a PWM signal represents information of 1-bit logical value of digital data to be transmitted in one cycle of the PWM signal. The transmission data bit string shown in FIG. 3 (1) is converted into the PWM signal shown in FIG. 3 (2), and then amplitude-modulated by the carrier signal to be transmitted as the transmission signal shown in FIG. 3 (3). When the signal is received by the tuning circuit of the tuning circuit unit 3 shown in FIG. 2, the received signal is extended in the time axis direction due to the damped oscillation phenomenon of the tuning circuit, and as shown in FIG. Interfering with “0” of the fourth bit, the signal continues to the data fetch clock position of the fourth bit of the binarized output as shown in FIGS. 3 (5) and 3 (6). As shown in 3 (7), the fourth bit of the received data bit string is erroneously received as “1”.
Next, the operation in Embodiment 1 of the present invention for avoiding such erroneous reception of received data will be described.

  FIG. 4 is a diagram showing the waveform of the PWM signal in the first embodiment of the present invention. In FIG. 4, the vertical axis represents voltage and the horizontal axis represents time. In the first embodiment, a pulse having a period tp and a high level tw1 is a first duty, and a pulse having a high level tw2 is a PWM signal having a second duty. Note that a relationship of tp> tw1> tw2 is established.

First, detection of a reading start point of digital data transmitted and received by the communication device 1 will be described.
FIG. 5 shows the structure of the data frame in Embodiment 1 of the present invention. The communication control unit 7 generates data frames that the communication device 1 transmits and receives to and from each other. As shown in FIG. 5, the data frame includes a preamble portion 10 and a data portion 11. The preamble part 10 is a signal part for synchronizing the reading timing of the data frame, and the data part 11 is a signal part of digital data.

  FIG. 6 is a diagram showing details of the preamble part and modulation / demodulation operation in Embodiment 1 of the present invention. As shown in FIG. 6 (1), the communication control means 7 generates a pulse train of the preamble section 10 composed of 8 pulses of the first duty PWM signal and 8 pulses of the second duty PWM signal, and has an amplitude. Input to the modulation circuit unit 8. As shown in FIG. 6B, the amplitude modulation circuit unit 8 modulates the amplitude of the pulse train of the input PWM signal at a predetermined carrier frequency and inputs it to the transmission amplifier 9 as a transmission signal. The transmission amplifier 9 amplifies the input transmission signal to a predetermined power and then inputs it to the tuning circuit unit 3. The tuning circuit unit 3 radiates the input transmission signal from the antenna and propagates through the space.

  The propagated transmission signal is received by the tuning circuit unit 3 of the other communication device 1, but the output waveform of the tuning circuit unit 3 differs depending on the propagation distance. FIG. 6 (3) shows a reception waveform of the tuning circuit unit 3 in the case of a short distance. When the distance is short, the received energy is large, so that the damped oscillation continues for a long time. The PWM signal with the duty of the current value continues until the next cycle. When this signal is binarized at, for example, a half level of the signal, as shown in FIG. 6 (4), the first half of the preamble section 10 composed of the PWM signal having the first duty seems to continue at a high level. Signal. In the second half of the preamble section 10 composed of the PWM signal having the second duty, the received wave does not continue until the next period. Therefore, as shown in FIG. 6 (4), a pulse having the PWM period tp can be obtained.

  Next, FIG. 6 (3 ′) is a reception waveform of the tuning circuit unit 3 in the case of a long distance. When the distance is long, the received vibration is small, so that the damped oscillation converges quickly. As shown in '), a pulse having a PWM period tp can be obtained for both the first duty and the second duty.

  As described above, the demodulated signal input to the communication control means 7 differs depending on the distance, but as shown in FIG. 6 (5), the signal is generated at a position ½ of tp from the rising edge A of the demodulated signal. The start of the preamble can be detected by checking the level and detecting a high level for a predetermined period, in this example, eight periods. Next, after detecting the eighth high level, the communication control means 7 opens the tp period, detects the next demodulated signal rising edge B, and adds a point of every tp period with 1/2 tp time as the reference timing of the data reading position. And The start of data is a point of 8 tp period after B detection, and the start point of data can be detected.

Next, encoding of digital data constituting the data part of the data frame will be described.
FIG. 7 is a diagram showing the first encoding of the data part in the first embodiment of the present invention. FIG. 7 shows a specific example in which, for example, a logical value of 1 bit of digital data is encoded with a PWM signal of 6 cycles. As shown in FIG. 7, the communication control means 7 encodes the logical value 1 with the pulse train of the PWM signals having the first, second, first, second, first, and second duties, and outputs the logical value 0. Is encoded with a pulse train of PWM signals having second, first, second, second, second and second duty.

  By encoding digital data using such a combination of PWM signals, even if the transmission distance is short and the damped oscillation continues for a long time, and the first duty PWM signal after reception continues until the next cycle, communication control is performed. The means 7 inspects the signal at the reference timing of the data reading position obtained by the preamble unit 10. When the logical value is 1, three pulses of the first duty are detected in the 6 tp period, When the value is 0, one pulse with the first duty can be detected, so that the logical value 1 or 0 can be determined regardless of the distance.

  FIG. 8 is a diagram showing the second encoding of the data part in the first embodiment of the present invention. As shown in FIG. 8, for example, 1-bit logical value of digital data may be encoded with a 4-cycle PWM signal. As shown in FIG. 8, the communication control means 7 encodes the logical value 1 with the pulse train of the PWM signals having the first, second, first, and second duties, and sets the logical value 0 to the second and second values. , Encoding with a pulse train of PWM signals of second and second duty.

  By encoding digital data using such a combination of PWM signals, even if the transmission distance is short and the damped oscillation continues for a long time, and the first duty PWM signal after reception continues until the next cycle, communication control is performed. The means 7 inspects the signal at the reference timing of the data reading position obtained by the preamble unit 10. When the logical value is 1, two pulses of the first duty are detected in the 4 tp period, When the value is 0, the pulse of the first duty is not detected, so whether the logical value is 1 or 0 is determined depending on whether a predetermined number of pulses of the first duty are detected during the period of 4 tp period. It becomes possible.

As described above, in the first embodiment of the present invention, the preamble portion 10 is generated at the head of the data frame, and the logical value of the digital data is encoded into the pulse trains of a plurality of PWM signals having different duty ratios. Even when the received signal is extended to the time axis method due to the damped oscillation phenomenon of the circuit, the data reading start point can be detected, the logical value of the digital data can be determined, and the reading error of the received data can be reduced. Can do. In addition, a receiving circuit using an inexpensive tuning circuit can be configured.
As a result, wireless communication can be used for relatively low-cost products such as home appliances, sensors, and remote controllers, and network home appliances with good installability can be realized.

  In the first embodiment, a case has been described in which 1-bit logical value of digital data is encoded with a combination of PWM signals having different duty ratios of 6 cycles or 4 cycles, but the present invention is not limited to this. Other combinations may be used.

Embodiment 2. FIG.
FIG. 9 is a diagram showing a configuration of a communication apparatus according to Embodiment 2 of the present invention. In the first embodiment, the cutoff frequency of the LPF of the detection unit 5 is set lower than the carrier frequency, and the output of the detection unit 5 is binarized by the comparator 6, but in the second embodiment, the detection unit 5 For example, the cutoff frequency of the LPF is set lower than 1 / (8 * tp), and the comparator 6 is not provided as shown in FIG.
Next, a transmission method in which digital data transmission / reception with such a configuration is performed by a PWM signal will be described.

  FIG. 10 is a diagram showing details of the preamble part and modulation / demodulation operation in the second embodiment of the present invention. As shown in FIG. 10 (1), the communication control means 7 generates a pulse train of the preamble section 10 composed of 8 pulses of the first duty PWM signal and 8 pulses of the second duty PWM signal, and performs amplitude modulation. Input to the circuit unit 8. As shown in FIG. 10 (2), the amplitude modulation circuit unit 8 modulates the amplitude of the pulse train of the input PWM signal at a predetermined carrier frequency and inputs it to the transmission amplifier 9 as a transmission signal. The transmission amplifier 9 amplifies the input transmission signal to a predetermined power and then inputs it to the tuning circuit unit 3. The tuning circuit unit 3 radiates the input transmission signal from the antenna and propagates through the space.

The propagated transmission signal is received by the tuning circuit unit 3 of the other communication device 1, but the output waveform of the tuning circuit unit 3 differs depending on the propagation distance.
FIG. 10 (3) shows a reception waveform in the case of a short distance. When the distance is short, the received energy is large, so that the damped oscillation continues for a long time. Therefore, the PWM signal of the first duty having a high duty is obtained. Will continue until the next cycle.
As shown in FIG. 10 (4), the reception signal output by the LPF included in the detection unit 5 has a high-level voltage (Vh) during the first duty period, and the second duty period is The waveform continues with a low level voltage (Vl).
The communication control means 7 sets the average value of the voltage obtained based on Vh in the first 8 tp period and Vl in the next 8 tp period, (Vh−Vl) / 2, as a threshold voltage for signal reading only for reception of the data frame. .

  FIG. 11 is a diagram showing encoding of the data part in the second embodiment of the present invention. FIG. 11 is a specific example in which, for example, a logical value of 1 bit of digital data is encoded by an 8-cycle PWM signal. As shown in FIG. 11, the communication control means 7 encodes a logical value 1 with a pulse train of a PWM signal having a first duty of 8 cycles, and a logical value 0 is a PWM signal having a second duty of 8 cycles. Encode with pulse train.

  By encoding digital data with such a pulse train of PWM signals, the logical value 1 or 0 of the received digital data in the data section 11 is the same as the LPF output shown in FIG. Since it is converted to a voltage level, even if the PWM signal of the first duty after reception is continued until the next period due to the transmission distance by reading every 8 tp period at the threshold of (Vh−Vl) / 2, A logical value of 1 is a high level voltage (Vh), and a logical value of 0 is a low level voltage (Vl), so that a logical value of 1 or 0 can be discriminated.

As described above, in the second embodiment, by decoding the average value of the pulse train voltage of the preamble portion output by the LPF into the logical value of the digital data as a threshold voltage, the time is reduced due to the damped oscillation phenomenon of the tuning circuit. Even when the received signal is extended to the axis method, the reading error of the received data can be reduced.
Furthermore, the number of parts can be reduced by adopting a configuration in which no comparator is provided.

  In the second embodiment, the cutoff frequency of the LPF of the detection unit 5 is set lower than 1 / (8 * tp), and the 1-bit logical value of the digital data is encoded with an 8-period PWM signal. As described above, the present invention is not limited to this, and encoding by another number of periods and the cutoff frequency of the LPF may be used.

Embodiment 3 FIG.
In the first and second embodiments, the amplitude modulation circuit unit 8 amplitude-modulates the PWM signal at a predetermined carrier frequency, and the modulation signal is received by the tuning circuit having a resonance point at the predetermined carrier frequency of the tuning circuit unit 3. However, amplitude modulation and demodulation may be performed using a plurality of carrier frequencies. In this way, by using a plurality of carrier frequencies, it is possible to selectively transmit / receive a specific communication device or specific transmit / receive data.

Embodiment 4 FIG.
In the first to third embodiments, the case where the radio wave medium 2 is used as the transmission medium of the communication apparatus has been described. However, instead of the radio medium 2, infrared rays or wires as shown in FIG. A highly reliable communication device can be obtained at a low cost with the same configuration even when using a cable or the like.

It is the figure which showed the structure of the communication system in Embodiment 1 of this invention. It is the figure which showed the structure of the communication apparatus in Embodiment 1 of this invention. It is the figure which showed the data transmission / reception method by the conventional PWM signal. It is the figure which showed the waveform of the PWM signal in Embodiment 1 of this invention. It is the figure which showed the structure of the data frame in Embodiment 1 of this invention. It is a figure which shows the detail of the preamble part in Embodiment 1 of this invention, and modulation / demodulation operation | movement. It is the figure which showed the 1st encoding of the data part in Embodiment 1 of this invention. It is the figure which showed the 2nd encoding of the data part in Embodiment 1 of this invention. It is the figure which showed the structure of the communication apparatus in Embodiment 2 of this invention. It is a figure which shows the detail of the preamble part in Embodiment 2 of this invention, and modulation / demodulation operation | movement. It is the figure which showed the encoding of the data part in Embodiment 2 of this invention. It is the figure which showed the structure of the communication system in Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication apparatus, 2 Wireless medium, 3 Tuning circuit part, 4 Reception amplifier, 5 Detection part, 6 Comparator, 7 Communication control means, 8 Amplitude modulation circuit part, 9 Transmission amplifier, 10 Preamble part, 11 Data part, 12 Transmission medium .

Claims (14)

A communication control means for encoding a logical value of digital data with a pulse train of a pulse width modulation signal composed of a plurality of pulses having different duty ratios;
Modulation means for modulating a pulse train of the pulse width modulation signal into a transmission signal;
A transmission means for transmitting the transmission signal;
With
The communication control means includes a first pulse train of the pulse width modulation signal comprising a pulse train obtained by combining one or more of a first duty having a predetermined duty ratio and a second duty having a duty ratio lower than the first duty. To encode a first logical value that is a logical value of the digital data,
A second logical value, which is a logical value of the digital data, is encoded by a second pulse train of the pulse width modulation signal composed of a pulse train of either the first duty or the second duty. and to that communication apparatus. A communication control means for encoding a logical value of digital data with a pulse train of a pulse width modulation signal composed of a plurality of pulses having different duty ratios;
Modulation means for modulating a pulse train of the pulse width modulation signal into a transmission signal;
A transmission means for transmitting the transmission signal;
With
The communication control means includes a first pulse train of the pulse width modulation signal comprising a pulse train obtained by combining one or more of a first duty having a predetermined duty ratio and a second duty having a duty ratio lower than the first duty. To encode a first logical value that is a logical value of the digital data,
The digital data is a logical value of the digital data by a second pulse train of the pulse width modulation signal that is composed of a pulse train combining one or more of the first duty and the second duty and is different from the first pulse train. the second logic value characterized by encoding communication device. Receiving means for receiving a transmission signal in which digital data is encoded into a pulse train of a pulse width modulation signal and the pulse train of the pulse width modulation signal is modulated;
Detecting means for demodulating the transmission signal into a pulse train of a pulse width modulation signal;
A communication apparatus comprising: communication control means for decoding a pulse train of the pulse width modulation signal demodulated by the detection means into a logical value of the digital data with a pulse number of a predetermined duty ratio. The receiving means uses a first pulse train of the pulse width modulation signal composed of a pulse train in which one or more of a first duty having a predetermined duty ratio and a second duty having a duty ratio lower than the first duty are combined. A first logical value that is a logical value of the digital data is encoded, and the second pulse train of the pulse width modulation signal including the pulse train of either the first duty or the second duty A second logical value, which is a logical value of digital data, is encoded, the encoded pulse width modulated signal is received as a modulated transmission signal;
The communication control means is a pulse train of the pulse width modulation signal demodulated by the detection means, which is either the first pulse train or the second pulse train, depending on the number of pulses equal to or higher than the first duty ratio. 4. The communication apparatus according to claim 3 , wherein the communication device is discriminated and decoded into a logical value of the digital data. The receiving means uses a first pulse train of the pulse width modulation signal composed of a pulse train in which one or more of a first duty having a predetermined duty ratio and a second duty having a duty ratio lower than the first duty are combined. The first logical value, which is the logical value of the digital data, is encoded and is composed of a pulse train combining one or more of the first duty and the second duty, and the pulse is different from the first pulse train. A second logical value that is a logical value of the digital data is encoded by the second pulse train of the width modulation signal, and the transmission signal obtained by modulating the encoded pulse width modulation signal is received.
The communication control means is a pulse train of the pulse width modulation signal demodulated by the detection means, which is either the first pulse train or the second pulse train, depending on the number of pulses equal to or higher than the first duty ratio. 4. The communication apparatus according to claim 3 , wherein the communication device is discriminated and decoded into a logical value of the digital data. The communication control unit generates a preamble portion including a pulse train of a pulse width modulation signal in which a plurality of pulses having different duty ratios are arranged in a predetermined manner at the head of a data frame composed of the digital data. Item 3. The communication device according to Item 1 or 2 . The receiving means has a pulse train of the pulse width modulation signal having a preamble portion composed of a pulse train of a pulse width modulation signal in which a plurality of pulses having different duty ratios are arranged in a predetermined manner at the head of a data frame composed of the digital data Receive the modulated transmission signal,
Wherein the communication control means according to any of claims 3-5, characterized in that the reading position of the pulse train of the pulse width modulated signal demodulated by the detection unit is determined based on the pulse train of the preamble portion Communication equipment. A preamble portion including a pulse train of a pulse width modulation signal in which a first duty and a second duty having different duty ratios are arranged in a predetermined manner is generated at the head of a data frame composed of digital data. A communication control means for encoding a logical value of 1 and a second logical value by a pulse width modulation signal comprising a pulse train of either the first duty or the second duty, respectively;
A communication apparatus comprising: modulation means for modulating a pulse train of the pulse width modulation signal into a transmission signal; and transmission means for transmitting the transmission signal. At the beginning of a data frame composed of digital data, a preamble portion comprising a pulse train of a pulse width modulation signal in which a first duty and a second duty having different duty ratios are arranged in a predetermined manner is provided. The logical value of 1 and the second logical value are encoded by a pulse width modulation signal composed of a pulse train of either the first duty or the second duty, respectively, and the encoded pulse width modulation signal is Receiving means for receiving the modulated transmission signal;
Detecting means for demodulating the transmission signal into a pulse train of a pulse width modulation signal using a low-pass filter whose cutoff frequency is a frequency determined by a period of the pulse train of the preamble part;
Using the average value of the voltage of the pulse width modulation signal of the preamble demodulated by the detection means as a threshold voltage, the pulse train of the pulse width modulation signal demodulated by the detection means is decoded into a logical value of the digital data. And a communication control means. Transmission / reception means for receiving or transmitting a signal in which digital data is encoded into a pulse train of a pulse width modulation signal and the pulse train of the pulse width modulation signal is modulated;
Detection means for demodulating the signal received by the transmission / reception means into a pulse train of a pulse width modulation signal;
The pulse train of the pulse width modulation signal demodulated by the detection means is decoded into the logical value of the digital data by the number of pulses of a predetermined duty ratio, the digital data is received, and the logic of the digital data to be transmitted Communication control means for encoding a value with a pulse train of a pulse width modulation signal composed of a plurality of pulses having different duty ratios;
A communication apparatus comprising: modulation means for modulating a pulse train of the pulse width modulation signal encoded by the communication control means into a signal to be transmitted. At the beginning of a data frame composed of digital data, there is a preamble part composed of a pulse train of a pulse width modulation signal in which a plurality of pulses having different duty ratios are arranged in a predetermined manner, and the digital data is encoded into the pulse train of the pulse width modulation signal Transmitting and receiving means for receiving or transmitting a signal that is modulated and a pulse train of the pulse width modulated signal is modulated;
Detection means for demodulating the signal received by the transmission / reception means into a pulse train of a pulse width modulation signal using a low-pass filter having a cutoff frequency as a frequency determined by a period of the pulse train of the preamble part;
The average value of the voltage of the pulse width modulation signal of the preamble demodulated by the detection means is used as a threshold voltage, and the pulse train of the pulse width modulation signal demodulated by the detection means is decoded into the logical value of the digital data. The digital data is received, and further, the logical value of the digital data to be transmitted is encoded with a pulse train of a pulse width modulation signal having a different duty ratio, and the duty ratio is different at the head of the data frame constituted by the digital data. Communication control means for generating a preamble portion comprising a pulse train of a pulse width modulation signal in which a plurality of pulses are arranged in a predetermined manner;
A communication device comprising: modulation means for modulating a pulse train of the pulse width modulation signal generated by the communication control means into a signal to be transmitted. Said modulating means, said pulse width modulated signal, according to claim 1, characterized in that the amplitude modulated by one or a plurality of carrier frequencies, 2, 6, 8, 1 0, 1 1 communication apparatus according to any one of . The detection means may include one or more of the amplitude-modulated signal which is amplitude-modulated by a carrier frequency, to any one of claims 3-5, 7, 9-1 1, characterized in that demodulating the pulse width modulated signal The communication device described. Said receiving means, one or a plurality of tuning circuits having a resonance point in the carrier frequency, according to claim 3 to 5, wherein the receiving the transmission signal, 7, 9-1 1, 1 3 either The communication device described.

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