JP4579007B2 - COMMUNICATION DEVICE USING MULTIPLE MODULATION METHODS AND TRANSMITTER DEVICE CONSTRUCTING THE COMMUNICATION DEVICE - Google Patents

Description

  The present invention relates to a communication apparatus, and more specifically, can select either an ASK (or BPSK) modulation method or a modulation method other than ASK (or BPSK) and transmit a modulated signal. The present invention relates to a communication device.

  In general, when communication is performed using a modulated signal, a modulation method may be selected according to the state of the transmission path and the amount of data to be sent. For example, an ASK modulation method and a QPSK modulation method can be used in a DSRC (Dedicated Short-Range Communication) system of an intelligent road traffic system.

  FIG. 12 is a diagram illustrating an example of a conventional communication apparatus that can select a modulation method. In this conventional communication apparatus, a modulated high-frequency signal is obtained by multiplying a high-frequency signal by a band-limited baseband signal when performing ASK modulation and QPSK modulation (for example, US Patent Publication). : US2003 / 0157888A1 (FIG. 5), corresponding basic application: see JP2003-244260).

  In FIG. 12, the conventional communication apparatus includes an ASK data generation unit 201, a QPSK data generation unit 202, a data selection unit 203, low-pass filter units 204 and 205, an orthogonal modulation unit 206, a signal source 207, A high-frequency power amplification unit 208 and a transmission antenna 209. Although the data selection unit 203 is not specified in the drawings of the above-mentioned prior patent documents, a configuration for preventing a collision between the output of the ASK data generation unit 201 and the output of the QPSK data generation unit 202 is essential. For this reason, the data selection unit 203 is added.

  The ASK data generation unit 201 generates ASK data from predetermined data. The QPSK data generation unit 202 generates QPSK data from predetermined data. The data selection unit 203 has two input terminals in which two terminals are paired and one output terminal in which two terminals are paired. Based on a modulation scheme designation signal given separately, the data selection unit 203 This switch controls connection switching. In the example of FIG. 12, a pair of data output from the ASK data generation unit 201 and zero value data are input to one input terminal (input 1), and QPSK data generation is performed to the other input terminal (input 2). A pair of data output by the unit 202 is input. The low-pass filter units 204 and 205 each remove the high-frequency component of the paired data output from the data selection unit 203 and output it as a baseband modulation signal. The quadrature modulation unit 206 performs frequency conversion using the signal generated by the signal source 207 on the baseband modulation signals output from the low-pass filter units 204 and 205, and performs high frequency modulation using ASK modulation or QPSK. Output a signal. The high frequency power amplifier 208 amplifies the high frequency signal modulated by the quadrature modulator 206 and radiates it from the transmission antenna 209.

  When ASK modulation is performed, the data selection unit 203 is notified of a modulation scheme designation signal that designates an ASK modulation scheme. Upon receiving this notification, the data selection unit 203 switches to the connection between the input 1 terminal and the output terminal, and the single-axis baseband modulation signal and the zero-value signal corresponding to the ASK modulation output from the ASK data generation unit 201. Are output to the low-pass filter units 204 and 205.

  When performing QPSK modulation, the data selection unit 203 is notified of a modulation scheme designation signal that designates the QPSK modulation scheme. In response to this notification, the data selection unit 203 switches the connection between the input 2 terminal and the output terminal, and outputs a pair of baseband modulation signals corresponding to the QPSK modulation output from the QPSK data generation unit 202 to the low frequency band. Output to the pass filter units 204 and 205.

Here, the relationship between ASK modulation and QPSK modulation and the transmission power output from the high frequency power amplifier 208 will be described. The transmission power is determined by the power of the high frequency signal output from the quadrature modulation unit 206 and the gain of the high frequency power amplification unit 208. The power of the high-frequency signal output from the quadrature modulation unit 206 is determined by the amplitude of data output from the ASK data generation unit 201 and the coefficients of the low-pass filter units 204 and 205 when performing ASK modulation, and QPSK when performing QPSK modulation. It is determined by the amplitude of data output from the data generation unit 202 and the coefficients of the low-pass filter units 204 and 205. Therefore, the ratio between the transmission power output from high-frequency power amplification section 208 when performing ASK modulation and the transmission power output from high-frequency power amplification section 208 when performing QPSK modulation is a fixed value determined by design.
Japanese Patent Laying-Open No. 2003-244260 (7th page, FIG. 5) US Patent Application Publication No. 2003/0157888

  A communication system is usually composed of a plurality of communication devices, and the specifications of the plurality of communication devices differ according to the type. For example, a communication apparatus that constitutes a base station of a wireless communication system greatly affects the operation of the entire system. On the other hand, since a general user owns a communication device constituting a mobile device, low cost is important.

  Among the elements constituting the communication device, one of the elements related to both the small number of transmission errors and the cost is a high frequency power amplifier. For communication devices where low transmission errors are important, it is desirable to select one with high output power. On the other hand, in communication devices where low cost is important, output power is somewhat low. It is desirable to select an inexpensive one. Also, when selecting a high-frequency power amplifier, it should be noted that the power that can be output differs depending on the modulation method.

  A narrow communication system will be described as an example. The standard for this narrow-area communication system includes an upper limit of transmission power for ASK modulation and π / 4 shift QPSK (hereinafter referred to as QPSK) modulation for class 1 base stations and mobile devices. Is defined as 10 mW. Here, the transmission power is given by the peak value of the antenna power during ASK modulation and by the average value of the antenna power during QPSK modulation. On the other hand, an inexpensive high-frequency power amplifier designed to output a peak value of 10 mW when performing ASK modulation can output only an average value of about 5 mW when performing QPSK modulation.

In a communication device in which a small number of transmission errors are important, there is a restriction that the sensitivity of the communication device with a focus on cost, which is a communication partner, is not so good, and a high-frequency power amplifier that can output 10 mW when performing QPSK modulation is selected. Is desirable. Therefore, the transmission power when performing ASK modulation / QPSK modulation is desirably 10 mW / 10 mW which is the upper limit of the standard. On the other hand, in a communication device where low cost is important, the power that can be output when performing QPSK modulation is about 5 mW, but it is desirable to select an inexpensive high-frequency power amplifier. Therefore, the transmission power when performing ASK modulation / QPSK modulation is preferably 10 mW / 5 mW.
That is, the ratio of the transmission power output from the high-frequency power amplification unit when performing ASK modulation and the transmission power output from the high-frequency power amplification unit when performing QPSK modulation differs depending on the type of communication apparatus.

  However, in the conventional communication apparatus, the ratio between the transmission power output from the high frequency power amplification unit when performing ASK modulation and the transmission power output from the high frequency power amplification unit when performing QPSK modulation is lower than that of the data generation unit. It was a fixed value determined by the design of the bandpass filter section. Therefore, a plurality of types of data generation units or low-pass filter units are required depending on the type of communication device, and the cost reduction effect due to mass production cannot be obtained sufficiently.

  In addition, when a data generation unit and a low-pass filter unit that are not suitable for the type of communication device are used, an expensive high-frequency power amplification unit is required. For example, a case where a data generation unit and a low-pass filter unit designed so that the ratio of transmission power when performing ASK modulation / QPSK modulation is “1” is used in a communication apparatus where low cost is important. Think. In this case, an inexpensive high-frequency power amplifying unit has a transmission power of 5 mW not only when performing QPSK modulation but also when performing ASK modulation, causing a problem in transmission reliability. That is, an inexpensive high-frequency power amplifier cannot be used.

Therefore, in order to realize the two types of transmission power ratio when ASK modulation / QPSK modulation is 10 mW / 10 mW = 1 and 10 mW / 5 mW = 2 with the same communication apparatus, Usually, the following configuration (A) or (B) is required.
(A) A multiplier for amplifying the amplitude by √2 is provided before the orthogonal modulation unit 206 in FIG. In this configuration, it is necessary to handle a number of about 1.4 times, which increases the number of digits when expressed in binary, increasing the hardware scale of digital signal processing and increasing the cost.
(B) A variable attenuator or a variable gain amplifier is provided at the input of the high frequency power amplifier 208 in FIG. In this configuration, the addition of high-frequency components degrades the stability of transmission power and increases the cost.

  Therefore, an object of the present invention is to add transmission power without adding a special configuration when there are a plurality of types of communication devices having different transmission power specifications in a communication system using a plurality of modulation schemes. It is an object of the present invention to provide a communication device that achieves cost reduction and circuit sharing without deteriorating stability.

  The present invention provides communication for performing data communication by selectively using a uniaxial modulation method using an ASK modulation method or a BPSK modulation method and a biaxial modulation method using a modulation method other than the ASK modulation method or the BPSK modulation method. The present invention is directed to an apparatus and a transmission apparatus constituting the communication apparatus. And in order to achieve the said objective, the transmitter of this invention is equipped with the 1st and 2nd signal production | generation part, the modulation system selection part, the orthogonal modulation part, and the high frequency power amplification part.

  The first signal generation unit generates a baseband modulation signal for a single-axis modulation method. The second signal generation unit generates a baseband modulation signal pair for the biaxial modulation method. When performing biaxial modulation, the modulation scheme selection unit selects the baseband modulation signal pair generated by the second signal generation unit, and when performing single axis modulation, the baseband modulation generated by the first signal generation unit Either a signal pair of a signal and a fixed value signal or a signal pair using the baseband modulated signal on both axes is selected according to transmission power. The orthogonal modulation unit performs frequency conversion on the signal pair selected by the modulation method selection unit, and outputs a modulated high-frequency signal. The high frequency power amplification unit amplifies the high frequency signal modulated by the quadrature modulation unit and transmits the amplified signal from the antenna.

  Preferably, the modulation scheme selection unit inputs the baseband modulation signal generated by the first signal generation unit and the fixed value signal, and outputs one of the signals based on a predetermined power ratio designation signal. A ratio switch, a signal pair of a baseband modulation signal generated by the first signal generation unit and a signal output by the power ratio switch, and a baseband modulation signal pair generated by the second signal generation unit; It is comprised with the modulation system switch which outputs either one signal pair based on a predetermined modulation system designation | designated signal.

  Alternatively, the modulation scheme selection unit inputs a signal pair of the baseband modulation signal and the fixed value signal generated by the first signal generation unit and the baseband modulation signal pair generated by the second signal generation unit. A modulation method switch that outputs one of the signal pairs based on a predetermined modulation method designation signal and a signal pair that is output by the modulation method switch are input, and when using single-axis modulation, a predetermined power ratio Based on the designated signal, the input signal pair is configured as it is or a power ratio switch that outputs either one of the signal pair using the baseband modulation signal of the input signals for both axes.

  Alternatively, the modulation scheme selection unit inputs a signal pair using the baseband modulation signal generated by the first signal generation unit for both axes and the baseband modulation signal pair generated by the second signal generation unit, When a single-axis modulation is used when a modulation method switch that outputs one of the signal pairs based on a predetermined modulation method specification signal and a signal pair output by the modulation method switch are used, a predetermined power ratio specification Based on the signal, the input signal pair is composed of a power ratio switch that outputs either one of the input signal pair as it is or one of the input signals that is switched to a fixed value signal.

  Each process performed by each configuration of the transmission apparatus described above can be regarded as a transmission method that provides a series of processing procedures. This method may be provided in the form of a program for causing a computer to execute a series of processing procedures. This program may be installed in a computer in a form recorded on a computer-readable recording medium. In addition, some or all of the functional blocks constituting the transmission apparatus described above may be realized as an LSI that is an integrated circuit.

  As described above, according to the communication device of the present invention, the ratio between the transmission power when ASK modulation is performed and the transmission power when modulation other than ASK is performed can be changed according to the type of the communication device. Therefore, it is possible to select and mount a high-frequency power amplification unit at a cost suitable for the type of the communication device. In addition, since most of the components other than the high-frequency power amplifier can be shared, it is possible to reduce the cost by mass production.

Examples of the uniaxial modulation method that can be used in the communication apparatus of the present invention include an ASK modulation method and a BPSK modulation method. It should be noted that the present invention can be applied to a modulation method that will be standardized in the future as long as it is a single-axis modulation method.
Hereinafter, the communication apparatus according to the present invention will be described by taking as an example a case where an ASK modulation method is used as a uniaxial modulation method and a modulation method other than ASK is used as a biaxial modulation method. This ASK modulation method includes a multi-level ASK modulation method. Further, modulation schemes other than ASK include modulation schemes having phase modulation components such as QPSK, QAM, and MSK.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of a communication apparatus 1 according to the first embodiment of the present invention. In FIG. 1, the communication device 1 according to the first embodiment includes a transmission unit 10, a reception unit 50, a data processing unit 60, a transmission antenna 70 and a reception antenna 80. The receiving unit 50 performs predetermined reception processing on the data received by the receiving antenna 80. The data processing unit 60 receives the received data from the receiving unit 50 and performs predetermined processing, and outputs transmission data generated by the predetermined processing to the transmitting unit 10. The transmission unit 10 performs predetermined transmission processing on the transmission data output from the data processing unit 60 and transmits the transmission data from the transmission antenna 70. The transmission antenna 70 and the reception antenna 80 may be shared. Further, when the communication device is a transmission device having only a transmission function, the configuration of the reception unit 50 and the reception antenna 80 is not necessary.

The communication apparatus 1 according to the present invention implements modulation scheme switching processing using the characteristic configuration of the transmission unit 10 as follows.
The transmission unit 10 includes a first signal generation unit 11, a second signal generation unit 12, a modulation scheme selection unit 13, an orthogonal modulation unit 16, a signal source 17, and a high frequency power amplification unit (PA) 18. Is provided. In the example using the ASK modulation method, the first signal generation unit 11 becomes the ASK modulation method baseband modulation signal generation unit 11 and the second signal generation unit 12 uses the non-ASK modulation method baseband modulation signal generation unit. 12 The modulation scheme selection unit 13 includes a power ratio switch 14 and a modulation scheme switch 15.

  The ASK modulation system baseband modulation signal generation unit 11 receives transmission data from the data processing unit 60 and generates a single-axis baseband modulation signal for the ASK modulation system. 2A and 3A show a configuration example of the baseband modulation signal generation unit 11 for the ASK modulation method. In the configuration shown in FIG. 2A, the transmission data is encoded by the encoding unit 111, mapped to a value corresponding to the ASK modulation scheme by the mapping unit 112, and then band-limited through the low-pass filter unit 113. Output as a baseband modulation signal. By making the circuit for the ASK modulation system different from the circuit for the modulation system other than ASK, the calculation coefficient used in the mapping unit 112 and the low-pass filter unit 113 is fixed, and the circuit scale is reduced. be able to.

  3A stores the calculation results of the mapping unit 112 and the low-pass filter unit 113 in FIG. 2A in the waveform ROM 116 in advance, and reads the calculation results from the waveform ROM 116 according to the transmission data. It is a thing. It is known that a baseband modulation signal can be generated if a waveform in a modulation symbol is stored for a data sequence corresponding to the response duration of the low-pass filter unit 113. Therefore, in the configuration shown in FIG. 3A, transmission data is encoded by the encoding unit 111, converted into a data sequence of a predetermined length by the shift register 115, and then given to the waveform ROM 116. In the waveform ROM 116, the waveform for the data series is read according to the time in the modulation symbol given by the counter 117, and is output as a baseband modulation signal. By making the circuit for the ASK modulation system different from the circuit for the modulation system other than ASK, the storage capacity of the waveform ROM 116 can be eliminated, and the circuit scale can be reduced.

  The non-ASK modulation system baseband modulation signal generation unit 12 receives transmission data from the data processing unit 60 and generates a baseband modulation signal in which both axes for any modulation system other than ASK are paired. 2B and 3B show a configuration example of the baseband modulation signal generation unit 12 for the non-ASK modulation method. In the configuration shown in FIG. 2B, the transmission data is encoded by the encoding unit 121 and mapped to a paired value according to an arbitrary modulation scheme by the mapping unit 122, and then the low-pass filter unit 123 and A band-limited baseband modulation signal is output through 124. Since the circuit for the modulation system other than ASK is configured separately from the circuit for the ASK modulation system, the calculation coefficients used in the mapping unit 122 and the low-pass filter units 123 and 124 are fixed values, and the circuit scale is reduced. Can be reduced.

  In the configuration shown in FIG. 3B, similarly to the configuration shown in FIG. 3A, the transmission data is encoded by the encoding unit 121, converted into a data series of a predetermined length by the shift register 125, and then the waveform ROM 126. Given to. In the waveform ROM 126, the waveform for the data series is read according to the time in the modulation symbol given by the counter 127, and is output as a baseband modulation signal. Since the circuit for the modulation system other than ASK is configured separately from the circuit for the ASK modulation system, useless storage capacity of the waveform ROM 126 can be eliminated and the circuit scale can be reduced.

  The power ratio switch 14 has two input terminals and one output terminal, and is a switch that controls connection switching between the input terminal and the output terminal based on a separately provided designation signal. In the example of FIG. 1, a signal output from the baseband modulation signal generation unit 11 for ASK modulation system is input to one input terminal a, and a signal having a value of zero is input to the other input terminal b. A signal specifying the power ratio is provided. The designation of the ASK power ratio may be an electrical designation set in a register or the like, or a mechanical designation such as a switch contact position. The zero-value signal input to the input terminal b means a fixed-value signal in which the amplitude of the high-frequency signal is zero when input to the quadrature modulation unit 16.

  The modulation system switch 15 has two input terminals in which two terminals are paired and one output terminal in which two terminals are paired, and the connection switching between the input terminal and the output terminal is performed based on a separately provided designation signal. It is a switch that controls In the example of FIG. 1, a pair of signals output from the baseband modulation signal generation unit 11 for ASK modulation method and a signal output from the power ratio switch 14 are input to one input terminal c and to the other input terminal d. A pair of signals output from the non-ASK modulation system baseband modulation signal generation unit 12 are respectively input, and a signal designating a modulation system is given as a designation signal.

  In the connection switching control performed by the modulation scheme selection unit 13, the power ratio switch 14 and the modulation scheme switch 15 are switched in the combination shown in FIG. 4 according to the modulation scheme and transmission power ratio to be applied to the transmission data. The modulation scheme is designated by a modulation scheme designation signal, and the transmission power ratio is designated by an ASK power ratio designation signal. The designation of the modulation method can be freely determined according to the type of transmission data, the communication partner, or a control signal received from the communication partner. The designation of the transmission power ratio is often fixed depending on the type of communication device, but may be changed dynamically.

(1) When modulation other than ASK is performed, a modulation method designation signal for designating a modulation method other than ASK is notified to the modulation method switch 15. Upon receiving this notification, the modulation system switch 15 switches to the connection between the input terminal d and the output terminal, and becomes a pair corresponding to the modulation other than ASK output by the non-ASK modulation system baseband modulation signal generation unit 12. The baseband modulated signal is output to the quadrature modulation unit 16.

(2) ASK power for designating ASK power ratio “1” when ASK modulation is performed and the ratio of the transmission power of the ASK modulation scheme to the transmission power of a modulation scheme other than ASK is 1 × The ratio designation signal is notified to the power ratio switch 14, and the modulation scheme designation signal for designating the ASK modulation scheme is notified to the modulation scheme switch 15. In response to this notification, the power ratio switch 14 switches the connection between the input terminal b and the output terminal, and outputs a signal having a value of zero to one terminal of the input terminal c of the modulation system switch 15. Also, the modulation system switch 15 switches to the connection between the input terminal c and the output terminal, and the uniaxial baseband modulation signal corresponding to the ASK modulation output from the ASK modulation system baseband modulation signal generation unit 11 and the value zero. Are output to the quadrature modulation unit 16.

(3) When ASK modulation is performed and the ratio of the transmission power of the ASK modulation scheme and the transmission power of a modulation scheme other than ASK is doubled, the ASK power designating the ASK power ratio “2” The ratio designation signal is notified to the power ratio switch 14, and the modulation scheme designation signal for designating the ASK modulation scheme is notified to the modulation scheme switch 15. In response to this notification, the power ratio switch 14 switches to the connection between the input terminal a and the output terminal, and the uniaxial baseband modulation corresponding to the ASK modulation output from the baseband modulation signal generation unit 11 for the ASK modulation method The signal is output to one terminal of the input terminal c of the modulation system switch 15. In addition, the modulation system switch 15 switches the connection between the input terminal c and the output terminal so that the uniaxial baseband modulation signal corresponding to the ASK modulation output from the ASK modulation system baseband modulation signal generation unit 11 is transmitted on both axes. The input signal pair is output to the quadrature modulation unit 16.

  The quadrature modulation unit 16 performs frequency conversion using the signal generated by the signal source 17 on the baseband modulation signal output from the modulation system switch 15, and outputs a high-frequency signal modulated by ASK modulation or other than ASK. To do. The high frequency power amplifier 18 amplifies the high frequency signal modulated by the quadrature modulator 16 and radiates it from the transmission antenna 70.

The transmission power when using π / 4 shift QPSK modulation (hereinafter referred to as QPSK) as a modulation other than ASK will be described by taking a narrowband communication system as an example. FIG. 5 shows an example of a signal space diagram at the time of quadrature modulation in the quadrature modulation unit 16. The I axis and the Q axis are the axes of the baseband modulation signals that form a pair.
In FIG. 5, points indicated by ◯ are QPSK signal points, and points indicated by X are ASK signal points. When the ASK power ratio designation is “1”, the I-axis input is a baseband modulation signal for the ASK modulation method and the Q-axis input is a signal having a value of zero. It becomes x mark of. On the other hand, when the ASK power ratio designation is “2”, since the I-axis input and the Q-axis input are the same baseband modulation signal for the ASK modulation method, the ASK signal points are the A mark and the C mark. Become a mark. Compared to the average amplitude of the QPSK modulation (circle), the peak amplitude of the ASK modulation (×) is 1 time when the ASK power ratio designation is “1” and when the ASK power ratio designation is “2”. √ Doubled.

  As described above, according to the communication device 1 according to the first embodiment of the present invention, the ratio of the transmission power when ASK modulation is performed and the transmission power when modulation other than ASK is performed is determined as the communication device. Therefore, it is possible to select and mount a high-frequency power amplifier having a cost suitable for the type of the communication device. In addition, since most of the components other than the high-frequency power amplifier can be shared, it is possible to reduce the cost by mass production.

  For example, when the ASK power ratio designation is “1”, the transmission power when performing ASK modulation / QPSK modulation can be designed to be 10 mW / 10 mW, which is the upper limit of the standard, and a high frequency capable of outputting 10 mW when performing QPSK modulation. By selecting the power amplifying unit, it is possible to realize a communication device in which little transmission error is important. On the other hand, when the ASK power ratio designation is “2”, the transmission power when performing ASK modulation / QPSK modulation can be designed to be 10 mW / 5 mW, and an inexpensive high-frequency power amplifying unit is selected. realizable.

In the above embodiment, the ASK power ratio designation is “1” when the ratio between the transmission power of the ASK modulation scheme and the transmission power of a modulation scheme other than ASK is one, and the ratio is twice. “2” was specified. However, this designation method is an example, and when the ratio is an arbitrary value determined based on error rate characteristics during communication, circuit feasibility, or the like, “1” is set, and the ratio is set to the arbitrary value. If the number is double, “2” may be designated.
In the above embodiment, the modulation system switch is arranged immediately after the power ratio switch in the modulation system selection unit. However, providing, for example, a D / A converter, a filter, a level conversion circuit, or the like between these switches is within the normal design range.

(Second Embodiment)
FIG. 6 is a block diagram showing a configuration of the communication apparatus 2 according to the second embodiment of the present invention. In FIG. 6, the communication device 2 according to the second embodiment includes a transmission unit 20, a reception unit 50, a data processing unit 60, a transmission antenna 70 and a reception antenna 80. The transmission unit 20 includes a first signal generation unit 11, a second signal generation unit 12, a modulation scheme selection unit 23, an orthogonal modulation unit 16, a signal source 17, and a high frequency power amplification unit 18. The communication device 2 according to the second embodiment differs from the communication device 1 according to the first embodiment in the configuration of the modulation scheme selection unit 23. Hereinafter, the different modulation scheme selection unit 23 will be described.

  The modulation method selection unit 23 includes a modulation method switch 25, a power ratio switch 24, and a switch control unit 26. The modulation system switch 25 has two input terminals in which two terminals are paired and one output terminal in which two terminals are paired. Based on a modulation system designation signal given separately, an input terminal and an output terminal This switch controls connection switching. In the example of FIG. 6, one input terminal c receives a pair of signals output from the ASK modulation system baseband modulation signal generation unit 11 and a zero value signal, and the other input terminal d receives non-ASK modulation. A pair of signals output from the system baseband modulation signal generation unit 12 are input.

  The switch control unit 26 controls connection switching of the power ratio switch 24 based on a separately provided modulation scheme designation signal and ASK power ratio designation signal. The power ratio switch 24 has two input terminals and one output terminal, and controls connection switching between the input terminal and the output terminal based on an instruction from the switch control unit 26. In the example of FIG. 6, one input terminal a receives a pair of signals output from the modulation system switch 25, and the other input terminal b receives the other signal.

In the connection switching control performed by the modulation scheme selection unit 23, the modulation scheme switch 25 and the power ratio switch 24 are switched in the combination shown in FIG. 7 according to the modulation scheme and transmission power ratio to be applied to the transmission data.
(1) When performing modulation other than ASK, a modulation method designation signal for designating a modulation method other than ASK is notified to the modulation method switch 25 and the switch control unit 26. Upon receiving this notification, the modulation system switch 25 switches to the connection between the input terminal d and the output terminal. Also, the switch control unit 26 receives this notification and performs control to switch the power ratio switch 24 to connection between the input terminal b and the output terminal. By this switching, a pair of baseband modulation signals corresponding to modulation other than ASK output from the non-ASK modulation baseband modulation signal generation unit 12 is output to the orthogonal modulation unit 16.

(2) ASK power for designating ASK power ratio “1” when ASK modulation is performed and the ratio of the transmission power of the ASK modulation scheme to the transmission power of a modulation scheme other than ASK is 1 × The ratio designation signal is notified to the switch controller 26, and the modulation scheme designation signal for designating the ASK modulation scheme is notified to the modulation scheme switch 25 and the switch controller 26. Upon receiving this notification, the modulation system switch 25 switches the connection between the input terminal c and the output terminal. Also, the switch control unit 26 receives this notification and performs control to switch the power ratio switch 24 to connection between the input terminal b and the output terminal. By this switching, a single-axis baseband modulation signal and a zero-value signal corresponding to the ASK modulation output from the ASK modulation scheme baseband modulation signal generation unit 11 are output to the quadrature modulation unit 16.

(3) When ASK modulation is performed and the ratio of the transmission power of the ASK modulation scheme and the transmission power of a modulation scheme other than ASK is doubled, the ASK power designating the ASK power ratio “2” The ratio designation signal is notified to the switch controller 26, and the modulation scheme designation signal for designating the ASK modulation scheme is notified to the modulation scheme switch 25 and the switch controller 26. Upon receiving this notification, the modulation system switch 25 switches the connection between the input terminal c and the output terminal. In response to this notification, the switch control unit 26 performs control to switch the power ratio switch 24 to the connection between the input terminal a and the output terminal. By this switching, a signal pair in which a single-axis baseband modulation signal corresponding to the ASK modulation output from the baseband modulation signal generation unit 11 for the ASK modulation method is input to both axes is output to the quadrature modulation unit 16.

As described above, the communication apparatus 2 according to the second embodiment of the present invention is particularly effective when the baseband modulation signal generation unit and the modulation method switch are integrally formed and the circuit cannot be changed in addition to the above-described effects. Useful.
In the above embodiment, the power ratio switch is arranged immediately after the modulation system switch in the modulation system selection unit. However, providing, for example, a D / A converter, a filter, a level conversion circuit, or the like between these switches is within the normal design range.

(Third embodiment)
FIG. 8 is a block diagram showing the configuration of the communication device 3 according to the third embodiment of the present invention. In FIG. 8, the communication device 3 according to the third embodiment includes a transmission unit 30, a reception unit 50, a data processing unit 60, a transmission antenna 70 and a reception antenna 80. The transmission unit 30 includes a first signal generation unit 11, a second signal generation unit 12, a modulation scheme selection unit 33, an orthogonal modulation unit 16, a signal source 17, and a high frequency power amplification unit 18. The communication device 3 according to the third embodiment differs from the communication device 1 according to the first embodiment in the configuration of the modulation scheme selection unit 33. Hereinafter, the different modulation scheme selection unit 33 will be described.

  The modulation method selection unit 33 includes a modulation method switch 35, a power ratio switch 34, and a switch control unit 36. The modulation system switch 35 has two input terminals in which two terminals are paired and one output terminal in which two terminals are paired. Based on a modulation system designation signal given separately, the input terminal and the output terminal This switch controls connection switching. In the example of FIG. 8, the signal output from the baseband modulation signal generator 11 for ASK modulation system is distributed to one input terminal c and input as a pair, and the other input terminal d is a base for non-ASK modulation system. A pair of signals output from the band modulation signal generation unit 12 are input.

  The switch control unit 36 controls connection switching of the power ratio switch 34 based on a separately provided modulation scheme designation signal and ASK power ratio designation signal. The power ratio switch 34 has two input terminals and one output terminal, and is a switch that controls connection switching between the input terminal and the output terminal based on an instruction from the switch control unit 36. In the example of FIG. 8, a zero-value signal is input to one input terminal a, and one of the signals output from the modulation system switch 35 is input to the other input terminal b.

In the connection switching control performed by the modulation scheme selection unit 33, the modulation scheme switch 35 and the power ratio switch 34 are switched in the combination shown in FIG. 9 according to the modulation scheme and transmission power ratio to be applied to the transmission data.
(1) When performing modulation other than ASK, a modulation method designation signal for designating a modulation method other than ASK is notified to the modulation method switch 35 and the switch control unit 36. Upon receiving this notification, the modulation system switch 35 switches the connection between the input terminal d and the output terminal. In response to this notification, the switch control unit 36 performs control to switch the power ratio switch 34 to the connection between the input terminal b and the output terminal. By this switching, a pair of baseband modulation signals corresponding to modulation other than ASK output from the non-ASK modulation baseband modulation signal generation unit 12 is output to the orthogonal modulation unit 16.

(2) ASK power for designating ASK power ratio “1” when ASK modulation is performed and the ratio of the transmission power of the ASK modulation scheme to the transmission power of a modulation scheme other than ASK is 1 × The ratio specifying signal is notified to the switch control unit 36, and the modulation method specifying signal for specifying the ASK modulation method is notified to the modulation method switch 35 and the switch control unit 36. Upon receiving this notification, the modulation system switch 35 switches the connection between the input terminal c and the output terminal. In response to this notification, the switch control unit 36 performs control to switch the power ratio switch 34 to the connection between the input terminal a and the output terminal. By this switching, a single-axis baseband modulation signal and a zero-value signal corresponding to the ASK modulation output from the ASK modulation scheme baseband modulation signal generation unit 11 are output to the quadrature modulation unit 16.

(3) When ASK modulation is performed and the ratio of the transmission power of the ASK modulation scheme and the transmission power of a modulation scheme other than ASK is doubled, the ASK power designating the ASK power ratio “2” The ratio specifying signal is notified to the switch control unit 36, and the modulation method specifying signal for specifying the ASK modulation method is notified to the modulation method switch 35 and the switch control unit 36. Upon receiving this notification, the modulation system switch 35 switches the connection between the input terminal c and the output terminal. In response to this notification, the switch control unit 36 performs control to switch the power ratio switch 34 to the connection between the input terminal b and the output terminal. By this switching, a signal pair in which a single-axis baseband modulation signal corresponding to the ASK modulation output from the baseband modulation signal generation unit 11 for the ASK modulation method is input to both axes is output to the quadrature modulation unit 16.

As described above, the communication device 3 according to the third embodiment of the present invention is particularly effective when the circuit cannot be changed because the baseband modulation signal generation unit and the modulation system switch are integrally formed in addition to the above-described effects. Useful.
In the above embodiment, the power ratio switch is arranged immediately after the modulation system switch in the modulation system selection unit. However, providing, for example, a D / A converter, a filter, a level conversion circuit, or the like between these switches is within the normal design range.

(Fourth embodiment)
FIG. 10 is a block diagram showing the configuration of the communication device 4 according to the fourth embodiment of the present invention. In FIG. 10, the communication device 4 according to the fourth embodiment includes a transmission unit 40, a reception unit 50, a data processing unit 60, a transmission antenna 70 and a reception antenna 80. The transmission unit 40 includes a first data generation unit 41, a second data generation unit 42, a modulation scheme selection unit 13, low-pass filter units 43 and 44, an orthogonal modulation unit 16, and a signal source 17. And a high frequency power amplifier 18. The communication device 4 according to the fourth embodiment includes a low-pass filter unit 113 included in the first signal generation unit 11 of the communication device 1 according to the first embodiment (see FIG. 2A). The low-pass filter unit 123 (see FIG. 2B) included in the second signal generation unit 12 is shared. Hereinafter, the first data generation unit 41, the second data generation unit 42, and the low-pass filter units 43 and 44 will be described.

  In the example using the ASK modulation method, the first data generation unit 41 becomes the ASK data generation unit 41, and the second data generation unit 42 becomes the non-ASK data generation unit 42. The ASK data generation unit 41 receives transmission data from the data processing unit 60 and generates single-axis data corresponding to the ASK modulation method. The non-ASK data generation unit 42 generates data for both axes corresponding to a modulation method other than ASK. The low-pass filter units 43 and 44 perform band limitation on the pair of signals output from the modulation scheme selection unit 13 and output the signals as baseband modulation signals. Since the low-pass filter units 43 and 44 perform a linear operation, the ratio of the data amplitude generated by the modulation scheme designation signal and the ASK power ratio designation signal is the ratio of the baseband modulation signal input to the quadrature modulation unit 16. Saved.

As described above, the communication device 4 according to the fourth embodiment of the present invention can also be applied to the configuration of a conventional communication device sharing a low-pass filter unit.
In the fourth embodiment, the configurations of the first data generation unit 41, the second data generation unit 42, and the low-pass filter units 43 and 44 are applied to the communication device 1 according to the first embodiment. However, this configuration can also be applied to the communication apparatuses 2 and 3 according to the second and third embodiments.

Here, a specific usage example of the switches included in the modulation scheme selection units 13 to 33 of the first to fourth embodiments will be described.
In general, a communication device modulates transmission data that is digital information into a high-frequency signal that is an analog waveform and transmits the modulated data. Therefore, it is preferable that the first half of the communication device is constituted by a digital signal processing circuit and the latter half is constituted by an analog signal processing circuit. However, since the boundary between the digital signal processing circuit and the analog signal processing circuit is left to design, the switch may handle a digital signal or an analog signal. Normally, when dealing with a digital signal, the signal is represented by a plurality of bits in parallel, so that the number of terminals of the switch is large, and when dealing with an analog signal, the number of terminals of the switch is small.

  Considering these things, a so-called data selector composed of a logic circuit can be considered as a digital switch. As an analog switch, a so-called analog switch composed of an FET or the like can be considered. Since these switches are composed of semiconductors, they can be easily integrated with other circuits. In particular, when the switch connection is fixed during operation of the communication apparatus (for example, when the ASK power ratio is not changed during operation), the analog switch may be mechanical. For example, a dip switch. Further, the switch may be switched by changing the wiring pattern of the printed circuit board used in the transmission device in accordance with the ASK power ratio designation. In this case, the ASK power ratio designation for controlling the switch corresponds to design data such as a wiring diagram. Further, the digital switch may be a mechanical switch in the same manner as the analog switch. However, since the number of terminals is large and the installation area is large, it is better to use when there is room in the communication device.

  A case will be described in which the ASK modulation method described in the first to fourth embodiments is a BPSK modulation method. In the case of the BPSK modulation method, the transmission power is generally defined by an average value as in the modulation methods other than BPSK. However, the modulation method with a long distance between signal points, such as BPSK, and the modulation method other than BPSK have different tolerances for non-linear distortion of transmission errors, and therefore the transmission power that can be output by the high-frequency power amplifier differs. As described above, even in the case of the BPSK modulation method, there may be a plurality of types of communication apparatuses having different transmission power specifications, so the same problem as in the case of the ASK modulation method occurs.

  Since the BPSK modulation method can be represented by only one of the paired baseband modulation signals as in the ASK modulation method, a communication apparatus can be realized with the same configuration as in the first to fourth embodiments. An example of a signal space diagram during quadrature modulation is shown in FIG. In FIG. 11, the points indicated by ◯ are QPSK signal points, and the points indicated by X are BPSK signal points. When the BPSK power ratio designation is “1”, the I-axis input is a baseband modulation signal for the BPSK modulation method, and the Q-axis input is a signal having a value of zero. It becomes x mark of. On the other hand, when the BPSK power ratio designation is “2”, since the I-axis input and the Q-axis input are the same baseband modulation signal for the BPSK modulation method, the signal points of the BPSK are the C mark and the D mark. Become a mark. Compared with the average amplitude of the QPSK modulation (circle), the average amplitude of the BPSK modulation (circle) is 1 when the BPSK power ratio designation is “1” and √ when the BPSK power ratio designation is “2”. It has doubled.

Note that each functional block of the first signal generation unit 11, the second signal generation unit 12, and the modulation scheme selection units 13 to 33 of the present invention is typically an integrated circuit LSI (depending on the degree of integration, (Referred to as an IC, a system LSI, a super LSI, or an ultra LSI) (see the broken line in FIG. 1). These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.
Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. Also, an FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.
Furthermore, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. There is a possibility of adaptation of biotechnology.

  The present invention can be used in a communication system using a plurality of modulation schemes such as a narrow-area communication system, and is particularly useful when there are communication apparatuses having different transmission power specifications.

The block diagram which shows the structure of the communication apparatus 1 which concerns on the 1st Embodiment of this invention. Configuration example of baseband modulation signal generation unit 11 for ASK modulation system Configuration example of baseband modulation signal generation unit 12 for non-ASK modulation system Another configuration example of the baseband modulation signal generation unit 11 for the ASK modulation method Another configuration example of the non-ASK modulation baseband modulation signal generation unit 12 The figure explaining the connection switching control performed in the modulation system selection part 13 The figure which shows the signal space diagram at the time of quadrature modulation (ASK modulation system and QPSK modulation system) The block diagram which shows the structure of the communication apparatus 2 which concerns on the 2nd Embodiment of this invention. The figure explaining the connection switching control performed by the modulation system selection part 23 The block diagram which shows the structure of the communication apparatus 3 which concerns on the 3rd Embodiment of this invention. The figure explaining the connection switching control performed by the modulation system selection part 33 The block diagram which shows the structure of the communication apparatus 4 which concerns on the 4th Embodiment of this invention. The figure which shows the signal space diagram at the time of quadrature modulation (BPSK modulation system and QPSK modulation system) Block diagram showing the configuration of a conventional communication device

Explanation of symbols

1-4 Communication devices 10, 20, 30, 40 Transmitter 11 Baseband modulation signal generator for ASK modulation scheme 12 Baseband modulation signal generator for non-ASK modulation scheme 13, 23, 33 Modulation scheme selectors 14, 24, 34 Power ratio switch 15, 25, 35 Modulation system switch 26, 36 Switch controller 16, 206 Quadrature modulator 17, 207 Signal source 18, 208 High frequency power amplifier 41, 201 ASK data generator 42, 202 Non-ASK data generation (QPSK data generator)
43, 44, 113, 123, 124, 204, 205 Low pass filter unit 50 Reception unit 60 Data processing unit 70, 80, 209 Antenna 111, 121 Encoding unit 112, 122 Mapping unit 115, 125 Shift registers 116, 126 Waveform ROM
117, 127 Counter 203 Data selection part

Claims (11)

A communication apparatus for performing data communication by selectively using a uniaxial modulation method using an ASK modulation method or a BPSK modulation method and a biaxial modulation method using a modulation method other than the ASK modulation method or the BPSK modulation method. ,
A receiving unit that performs a predetermined receiving process on received data;
A data processing unit that inputs received data from the receiving unit and performs predetermined processing, and outputs transmission data generated by the predetermined processing;
A transmission unit that performs predetermined transmission processing on transmission data output from the data processing unit,
The transmitter is
A first signal generation unit that generates a baseband modulation signal for a single-axis modulation method;
A second signal generation unit for generating a baseband modulation signal pair for the biaxial modulation scheme;
When performing bi-axial modulation ,
Choose Back SL baseband modulation signal to the second signal generator to generate,
There rows single shaft modulation, and, when the transmission power ratio between the transmission power of the transmission power and both axes modulated signal single shaft modulated signal is a predetermined value,
Select signal to the signal before Symbol fixed value and the first baseband modulation signal signal generating unit has generated,
When uniaxial modulation is performed and the transmission power ratio is twice the predetermined value,
Select the signal to with the baseband modulation signal both axes
And the modulation scheme selection section,
An orthogonal modulation unit that performs frequency conversion on the signal pair selected by the modulation method selection unit and outputs a modulated high-frequency signal;
A communication apparatus comprising: a high-frequency power amplification unit that amplifies a high-frequency signal modulated by the orthogonal modulation unit and transmits the signal from an antenna. The modulation scheme selector is
A power ratio switch that inputs the baseband modulation signal generated by the first signal generation unit and the signal of the fixed value, and outputs one of the signals based on a predetermined power ratio designation signal;
A signal pair of a baseband modulation signal generated by the first signal generation unit and a signal output from the power ratio switch and a baseband modulation signal pair generated by the second signal generation unit are input, and The communication apparatus according to claim 1, further comprising: a modulation system switch that outputs one of the signal pairs based on the modulation system designation signal. The modulation scheme selector is
Input a signal pair of a baseband modulation signal generated by the first signal generation unit and the fixed value signal and a baseband modulation signal pair generated by the second signal generation unit, and a predetermined modulation method A modulation system switch that outputs either one of the signal pairs based on the designated signal;
When the signal pair output from the modulation method switch is input and single-axis modulation is used, the input signal pair is left as it is or the base of the input signals is based on a predetermined power ratio designation signal. The communication apparatus according to claim 1, further comprising: a power ratio switch that outputs either one of a signal pair using a band modulation signal for both axes. The modulation scheme selector is
A signal pair using the baseband modulation signal generated by the first signal generation unit for both axes and the baseband modulation signal pair generated by the second signal generation unit are input, and a predetermined modulation scheme designation signal is input. A modulation system switch that outputs one of the signal pairs based on
When a signal pair output from the modulation system switch is input and single-axis modulation is used, the input signal pair is left as it is or one of the input signals is selected based on a predetermined power ratio designation signal. 2. The communication device according to claim 1, further comprising: a power ratio switch that outputs one of the signal pairs in which the signal is switched to the fixed value signal. A transmission apparatus that performs data transmission by selectively using a uniaxial modulation method using an ASK modulation method or a BPSK modulation method and a biaxial modulation method using a modulation method other than the ASK modulation method or the BPSK modulation method. ,
A first signal generation unit that generates a baseband modulation signal for a single-axis modulation method;
A second signal generation unit for generating a baseband modulation signal pair for the biaxial modulation scheme;
When performing bi-axial modulation ,
Choose Back SL baseband modulation signal to the second signal generator to generate,
There rows single shaft modulation, and, when the transmission power ratio between the transmission power of the transmission power and both axes modulated signal single shaft modulated signal is a predetermined value,
Select signal to the signal before Symbol fixed value and the first baseband modulation signal signal generating unit has generated,
When uniaxial modulation is performed and the transmission power ratio is twice the predetermined value,
Select the signal to with the baseband modulation signal both axes
And the modulation scheme selection section,
An orthogonal modulation unit that performs frequency conversion on the signal pair selected by the modulation method selection unit and outputs a modulated high-frequency signal;
A transmission apparatus comprising: a high-frequency power amplification unit that amplifies the high-frequency signal modulated by the orthogonal modulation unit and transmits the signal from an antenna. The modulation scheme selector is
A power ratio switch that inputs the baseband modulation signal generated by the first signal generation unit and the signal of the fixed value, and outputs one of the signals based on a predetermined power ratio designation signal;
A signal pair of a baseband modulation signal generated by the first signal generation unit and a signal output from the power ratio switch and a baseband modulation signal pair generated by the second signal generation unit are input, and The transmission apparatus according to claim 5, further comprising: a modulation system switch that outputs one of the signal pairs based on the modulation system designation signal. The modulation scheme selector is
Input a signal pair of a baseband modulation signal generated by the first signal generation unit and the fixed value signal and a baseband modulation signal pair generated by the second signal generation unit, and a predetermined modulation method A modulation system switch that outputs either one of the signal pairs based on the designated signal;
When the signal pair output from the modulation method switch is input and single-axis modulation is used, the input signal pair is left as it is or the base of the input signals is based on a predetermined power ratio designation signal. The transmission apparatus according to claim 5, further comprising: a power ratio switch that outputs one of a signal pair using a band modulation signal for both axes. The modulation scheme selector is
A signal pair using the baseband modulation signal generated by the first signal generation unit for both axes and the baseband modulation signal pair generated by the second signal generation unit are input, and a predetermined modulation scheme designation signal is input. A modulation system switch that outputs one of the signal pairs based on
When a signal pair output from the modulation system switch is input and single-axis modulation is used, the input signal pair is left as it is or one of the input signals is selected based on a predetermined power ratio designation signal. The transmission device according to claim 5, further comprising: a power ratio switch that outputs one of the signal pairs in which the signal is switched to the fixed value signal. Used in a transmission apparatus that performs data transmission by selectively using a uniaxial modulation method using an ASK modulation method or a BPSK modulation method and a biaxial modulation method using a modulation method other than the ASK modulation method or the BPSK modulation method. An integrated circuit,
Transmission comprising: an orthogonal modulation unit that outputs a high-frequency signal modulated by performing frequency conversion on a baseband modulation signal pair; and a high-frequency power amplification unit that amplifies the high-frequency signal modulated by the orthogonal modulation unit and transmits the amplified signal from an antenna Built into the device,
A first signal generation unit for generating a baseband modulation signal for a single-axis modulation method;
In the case of performing a second signal generation unit that generates a baseband modulation signal pair for the biaxial modulation method, and biaxial modulation ,
Choose Back SL baseband modulation signal to the second signal generator to generate,
There rows single shaft modulation, and, when the transmission power ratio between the transmission power of the transmission power and both axes modulated signal single shaft modulated signal is a predetermined value,
Select signal to the signal before Symbol fixed value and the first baseband modulation signal signal generating unit has generated,
When uniaxial modulation is performed and the transmission power ratio is twice the predetermined value,
Select the signal to with the baseband modulation signal both axes
It has integrated the circuit functioning as a modulation scheme selecting unit, an integrated circuit. A transmission method for performing data transmission by selectively using a uniaxial modulation method using an ASK modulation method or a BPSK modulation method and a biaxial modulation method using a modulation method other than the ASK modulation method or the BPSK modulation method. ,
A first signal generation step of generating a baseband modulation signal for a single-axis modulation method;
A second signal generating step for generating a baseband modulated signal pair for the biaxial modulation scheme;
When performing bi-axial modulation ,
Choose Back SL baseband modulation signal pair generated by the second signal generating step,
There rows single shaft modulation, and, when the transmission power ratio between the transmission power of the transmission power and both axes modulated signal single shaft modulated signal is a predetermined value,
Select signal to the previous SL signal having a fixed value and the baseband modulated signal generated by the first signal generating step,
When uniaxial modulation is performed and the transmission power ratio is twice the predetermined value,
Select the signal to with the baseband modulation signal both axes
And a select step, the transmission method. An orthogonal transformation step of performing frequency transformation on the signal pair selected in the selection step and outputting a modulated high-frequency signal;
The transmission method according to claim 10, further comprising an amplification step of amplifying the high-frequency signal modulated in the orthogonal modulation step and transmitting from the antenna.

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