JP2002325071A - Transmitter, receiver, transmitting method and receiving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a transmission method wherein quadrature multivalued modulation is applied to an UWB-IR system, high quality and high transmission rate are realized by increasing pulse intervals without decreasing transmission rate and the number of pulses, enables interference exclusion simultaneously, and the problem that a large amount of codes are used is solved by separating multiple access from codes showing information. SOLUTION: An orthogonal component element selecting circuit 102 outputs selectively a plurality of orthogonal component elements which are mutually orthogonal. An information signal from an information signal source 101 is converted into orthogonal component elements by the selecting circuit 102. A frame clock signal which is produced by a frame clock forming circuit 103 and a channeling code forming circuit 104 and turned into modulation codes is modulated by the orthogonal component elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transmitting device, a receiving device, a transmitting method, and a receiving method. More specifically, by applying the quadrature component element to ultra wideband communication, it is possible to increase the pulse interval without lowering the transmission rate and reducing the number of pulses by increasing the pulse interval.
Transmission that enables simultaneous interference elimination at a high transmission rate and avoids the problem of using a large number of codes, such as M-ary / SSMA modulation, by using separate codes for multiple access and information. The present invention relates to an apparatus, a receiving apparatus, a transmitting method, and a receiving method.

[0002]

2. Description of the Related Art In the information society in recent years, the social importance of information and communication has been increasing. In addition, wireless communication
It is clear from the spread of wireless communication devices such as mobile phones that there is an advantage in the possibility of obtaining information when compared with wired. Further, it is required to send not only audio information but also image information such as moving images and still images.

At present, as a method that satisfies this demand, IM
W-CDM in the air interface part of T2000
A and cdma2000 are adopted.
Also in wireless LANs, SS (Spread Spe
ctrum) method and OFDM (Orthogonal)
Frequency Division Multip
A wideband transmission scheme such as a lexing scheme is used.

[0004] On the other hand, Ultra W is a new transmission system with a broader band name than these wide band transmission systems.
ide Bandwidth-Ilmple Rad
The io (UWBIR) system has attracted attention in recent years, and Japanese Patent Publication No. Hei 10-508725 discloses an example of the UWB-IR system. In this system, baseband transmission using a pulse called 1 cycle (nanosecond) or less called "monocycle" is performed.

In such a transmission system, the pulse width is 1
ns or less, so that the transmission system occupies a larger occupied band than the conventional broadband transmission system. Due to the size of the occupied band, the transmission system in such a transmission system is susceptible to distortion of a transmission signal, but on the other hand, a delay wave due to multipath can be very finely decomposed, so that the transmission system is resistant to multipath. I can say. The UWB-IR system is expected as a high-quality and high-speed transmission system because of the high resolution of the path.

[0006] As a method for improving the frequency use efficiency in the conventional SS communication, the M-ary / SSMA method has been proposed. For example, in Japanese Patent No. 2968991, M
A communication device using a -nary / spread spectrum communication system is disclosed.

[0007]

In the case of multiple access by the UWB-IR system, time hopping (Time Hopping) modulation for shifting a pulse train by a code sequence unique to each user (station) is performed, and furthermore, time hopping is performed. The input data is put on the pulse train by adding a delay according to the input data to the pulse train that has been subjected to the hopping modulation. On the other hand, when the receiving side receives the pulse train on which the input data is loaded as described above, it correlates this pulse train with all the prepared code sequences and makes a majority decision. Inter-station interference depends on the probability that the pulse of the other station and the pulse of the own station hit.

In order to reduce the probability that the pulse hits, it is necessary to increase the pulse interval. However, increasing the pulse interval may lead to a decrease in transmission rate and an increase in the error rate due to a decrease in the number of pulses per symbol.

In the M-ary / SSMA system, 1
Since a plurality of codes are used by a plurality of users, a large number of codes are used by a plurality of users, and a correlator for all codes is required.

[0010] Accordingly, the present invention provides a UWB-IR system which employs M
-By applying ary, etc., the transmission rate is not reduced and the pulse interval is widened without reducing the number of pulses. An object of the present invention is to realize a transmission system that solves the problem of using a large number of codes, such as M-ary / SSMA modulation, by using different codes representing information.

[0011]

According to the method of the present invention, one or a plurality of orthogonal component elements are selected according to input data using a plurality of orthogonal component elements orthogonal to each other, and a monocycle is selected. Modulation is performed using the orthogonal component elements. In this method, when the same number of pulses as in the conventional method are used, a plurality of times of bit information can be transmitted, so that the pulse interval can be widened accordingly.

The present invention has the following features as means for achieving the above object.

According to the first aspect of the present invention, an information signal is converted into at least one of a plurality of orthogonal component elements orthogonal to each other, and the converted orthogonal component element is converted into a frame. The modulation is performed using at least one of a clock signal and a channelized code signal.

According to a second aspect of the present invention, there is provided an orthogonal component selection circuit for selecting at least one orthogonal component from a plurality of orthogonal components orthogonal to each other in accordance with an information signal. A frame clock generation circuit for generating a frame clock signal; a channelization code generation circuit for generating a channelization code signal; a frame clock generation circuit connected to the frame clock generation circuit and the channelization code generation circuit; A mixer for mixing and outputting a channelized code signal, and a modulation circuit for modulating an output of the mixer by the at least one orthogonal component element selected by the orthogonal component element selection circuit. .

According to a fifth aspect of the present invention, there is provided an orthogonal component selecting circuit for selecting at least one orthogonal component from a plurality of orthogonal components orthogonal to each other in accordance with an information signal. A frame clock generation circuit for generating a frame clock signal; a quadrature component selection circuit and a frame clock generation circuit connected to the quadrature component selection circuit; A modulation circuit that modulates, a channelization code generation circuit that generates a channelization code signal, a frame clock signal that is connected to the modulation circuit and the channelization code generation circuit, and that is modulated by the at least one orthogonal component element, A mixer for mixing and outputting the channelized code signal.

According to an eighth aspect of the present invention, there is provided an orthogonal component selection circuit for selecting at least one orthogonal component from a plurality of orthogonal components orthogonal to each other in accordance with an information signal. And a channelization code generation circuit for generating a channelization code signal, connected to an orthogonal component element selection circuit and a channelization code generation circuit, and mixing and outputting the at least one orthogonal component element and the channelization code signal. A mixer that generates a frame clock signal, and a modulation circuit that is connected to the mixer and the frame clock generation circuit and that modulates the frame clock signal according to the output of the mixer. It is characterized by.

According to an eleventh aspect of the present invention, an information signal is received, a k-bit information signal is converted and output in parallel, and the (k + 1) -th bit following the k-bit is output. A serial-to-parallel conversion circuit that outputs an information signal, a sequence code generation circuit that can generate a plurality of code sequences orthogonal to each other, and a selection circuit that is connected to the sequence code generation circuit and the serial-to-parallel conversion circuit. a selection circuit that receives and outputs at least one of the plurality of code sequences from the sequence code generation circuit in response to a k-bit information signal, and is connected to a selection circuit and a serial / parallel conversion circuit; Code sequence and k
An exclusive OR circuit that outputs an exclusive OR signal with the information signal of the (+1) th bit, a frame clock generation circuit that generates a frame clock signal, a channelization code generation circuit that generates a channelization code signal, and a frame. A first delay circuit connected to the clock generation circuit and the channelization code generation circuit for delaying and outputting the frame clock signal according to the channelization code signal; and a first delay circuit and the exclusive OR A second delay circuit that is connected to a circuit and adds a delay corresponding to the output of the exclusive OR circuit to the delayed frame clock signal.

According to a twelfth aspect of the present invention, a frame clock signal and a channelization code signal in which a quadrature component element or a component corresponding to the quadrature component included in a radiation signal is used by a transmitting apparatus are used. And a correlation value between the extracted orthogonal component element or a component corresponding thereto and each of the plurality of orthogonal component elements used by the transmitting apparatus.

According to a thirteenth aspect of the present invention, there is provided a frame clock generating circuit for generating a frame clock signal substantially identical to a frame clock signal used by a transmitting device, and a transmitting device comprising: A decode code generation circuit that generates and outputs a decode control signal corresponding to the channelization code to be used, is connected to the frame clock generation circuit and the decode code generation circuit, receives the frame clock signal and the decode control signal, and receives these signals. A mixer for mixing and outputting, a pulse generator connected to the mixer, generating a monocycle pulse triggered by the output of the mixer, sending the monocycle pulse to the primary demodulator, and a radiation signal from the transmitter. And a quadrature component extracted from the radiated signal using the monocycle pulse. And a correlator connected to the primary demodulator for receiving the extracted quadrature component signal and calculating a correlation value between a plurality of predetermined quadrature component components and the extracted quadrature component component. An aggregate and a maximum value selection circuit connected to the correlator aggregate and determining an orthogonal component element that has obtained a maximum correlation value from the correlation values calculated by the correlator aggregate.

According to a fourteenth aspect of the present invention, there is provided a frame clock generating circuit for generating a frame clock signal substantially identical to a frame clock signal used by a transmitting device, and a transmitting device comprising: A sequence code generation circuit that generates a sequence code corresponding to the channelization code to be used, a delay circuit that is connected to the frame clock generation circuit and the sequence code generation circuit, and that adds a delay to the frame clock signal according to the sequence code; A transmission waveform circuit that is connected to a circuit and generates a pulse train using the delayed frame clock signal as a trigger, and receives a radiation signal from the transmission device and is connected to the transmission waveform circuit and calculates a correlation between the radiation signal and the pulse train And a plurality of orthogonal code sequences connected to the correlation circuit and used by the transmission device. A correlator aggregate for calculating a correlation value between the output of the related circuit and each of the plurality of orthogonal code sequences; and a correlator aggregate connected to the correlator aggregate and calculating the maximum correlation value from the correlation values output by the correlator aggregate. A maximum value selection circuit to be selected and a sign determination circuit to determine whether the selected maximum value is positive or negative are provided.

It is to be noted that claims 15 to 28 are inventions of a method corresponding to the inventions of the apparatus of claims 1 to 14.

[0022]

Next, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment] First, the first embodiment of the present invention will be described.
The embodiment will be described with reference to FIGS.

[Exemplary Configuration of Transmitting Apparatus] FIG. 1 is a block diagram showing an exemplary configuration of the transmitting apparatus according to the first embodiment of the present invention. The transmitting apparatus according to the present embodiment includes an information signal source 101, an orthogonal component element selection circuit 102 connected to the information signal source 101, a frame clock generation circuit 10
3, a mixer 105 that mixes and outputs the output signals of the channelization code generation circuit 104, the frame clock generation circuit 103 and the channelization code generation circuit 104, and the output signal of the orthogonal component selection circuit 102. Vessel 10
5 and a pulse generation circuit 107 for pulsing the output signal from the modulation circuit 106. The output signal from the pulse generation circuit 107 is sent to the transmission antenna 108 and radiated into the air.

The information signal source 101 generates an information signal to be transmitted by the transmission device, and outputs the information signal to the orthogonal component element selection circuit 1.
02. The information signal may be a digital signal representing voice, data, image, or the like, an analog signal, or a composite signal thereof.

The orthogonal component element selection circuit 102 stores an orthogonal component element group composed of a plurality of orthogonal component elements that are orthogonal to each other, and based on the information signal sent from the information signal source 101, At least one orthogonal component element is selected from the component element group, output, and supplied to the modulation circuit 106.

Here, the orthogonal component element means one in which the inner product of a certain orthogonal component element and another orthogonal component element becomes zero. As the orthogonal component element, for example, a Walsh code sequence, a pseudo random noise (PN)
It may be an orthogonal code such as a code sequence, or a plurality of signals having waveforms which are orthogonal to each other, a plurality of signals having frequencies which are orthogonal to each other, and having a spatial axis which is orthogonal to each other. The present invention can be realized even if a plurality of signals are used as the orthogonal component element group. In the following description, it is assumed that orthogonal codes are used as orthogonal component elements.

[0028]

[Table 1] The above “Table 1” shows an example of the relationship between the orthogonal component element group stored in the orthogonal component element selection circuit 102 and the information signals associated with the orthogonal component element group.

In this example, the orthogonal component element group is composed of four orthogonal component elements, ie, orthogonal code sequences “0000” and “0”.
011 ”,“ 0101 ”, and“ 0110 ”. These orthogonal component elements are 2-bit signals“ 00 ”,“ 01 ”,“ 10 ”, and“ 1 ”sent from the information signal source 101.
The orthogonal component element selection circuit 102 selects one of the orthogonal code sequences according to the received 2-bit information signal, converts it into a signal, and outputs an orthogonal component element signal. . For example, if the received information signal is “10”, the corresponding orthogonal code sequence “0101” is output as an orthogonal component element signal.

The frame clock generation circuit 103 generates a frame clock signal. The frame clock signal is a monocycle pulse, for example, a pulse having a pulse interval of 25 to 1000 nanoseconds and a pulse width of 0.2 to 1.50 nanoseconds. The generated frame clock signal is supplied to the mixer 105.
Supplied to

The channelization code generation circuit 104 generates a channelization code uniquely defined for each transmission device, and supplies this to the mixer 105 as a channelization code signal.
The channelization code is a code sequence orthogonal to the channelization code of another transmission device, and for example, a PN code sequence is used.

The mixer 105 mixes the frame clock signal and the channelized code signal to obtain a signal (hereinafter, referred to as a signal).
(Referred to as a “channelized frame clock signal”) to the modulation circuit 106. Where "mixed"
Means synthesis of signals such as addition, multiplication, and delay. Considering that the frame clock signal is a monocycle pulse having a very small pulse interval, “mixing” is preferably “delay” for performing time position modulation (pulse position modulation).

The modulation circuit 106 modulates the channelized frame clock signal output from the mixer 105 with the quadrature component signal output from the quadrature component selection circuit 102. Here, the modulation method performed by the modulation circuit 106 includes frequency modulation (FM) and amplitude modulation (A
M), phase modulation, frequency displacement modulation (FSK), phase displacement modulation (PSK), pulse FM, or any other modulation technique, but the frame clock signal has a very small pulse interval. Considering that the pulse is a small monocycle pulse, the modulation performed here is preferably time position modulation (pulse position modulation. By performing such modulation, the modulation circuit 106 modulates the modulated coded channel. Generating a generalized frame clock signal,
It is sent to the pulse generation circuit 107.

The pulse generation circuit 107 generates an electric monocycle pulse by using the modulation-coded channelized frame clock signal as a trigger.

The generated electric monocycle pulse is sent to a transmitting antenna 108, which converts the electric monocycle pulse into an electromagnetic pulse,
It is sent to the receiving device as a radiation signal via a propagation medium such as air. This radiated signal becomes a wide band signal or an ultra wide band signal, and enables communication that is more resistant to multi-path and fading as compared with conventional spread spectrum (SS) communication and that realizes a higher transmission rate. Further, according to the transmission apparatus according to the present embodiment, the transmission rate is relatively improved by performing multi-level coding using orthogonal component elements, and it is possible to cope with a multi-user environment by using a channelized code sequence. Is possible.

[Another Configuration Example of Transmission Apparatus] Next, another configuration example of the transmission apparatus according to the present embodiment will be described. FIG. 2 is a block diagram of another configuration example of the transmitting apparatus according to the present embodiment. In this configuration example, the output of the channelization code generation circuit 104 is
3 is mixed with the output of the modulation circuit 106 and the mixer 105.

That is, as shown in FIG. 2, the information signal source 101 outputs an information signal to the orthogonal component element selection circuit 102. The orthogonal component element selection circuit 102 outputs the orthogonal component element signal to the modulation circuit 106. Further, the frame clock generation circuit 103 outputs a frame clock signal to the modulation circuit 106. The modulation circuit 106 modulates the frame clock signal using the quadrature component signal, and modulates the modulated clock frame signal into the mixer 10.
5 is output. The channelized code generation circuit 104 outputs the channelized code signal to the mixer 105, and the mixer 105 mixes the channelized code signal and the modulated frame clock signal, and outputs the modulated and encoded channelized frame clock signal to the pulse generation circuit. Output to 107. Pulse generation circuit 1
07 generates an electrical monocycle pulse triggered by the modulation-coded channelized frame clock signal. The generated electrical monocycle pulse is sent to transmit antenna 108, which converts the electrical monocycle pulse into an electromagnetic pulse,
It is sent to the receiving device as a radiation signal via a propagation medium such as air.

[Another Example of Configuration of Transmitting Apparatus]
Another configuration example of the transmitting apparatus according to the present embodiment will be described. FIG. 3 is a block diagram of still another configuration example of the transmitting apparatus according to the present embodiment. In this configuration example, the output of the channelization code generation circuit 104 is not mixed with the output of the frame clock generation circuit 103,
The signal is mixed with the output of the quadrature component selection circuit 102 by the mixer 105.

That is, as shown in FIG. 3, the information signal source 101 outputs an information signal to the orthogonal component element selection circuit 102. The orthogonal component element selection circuit 102 outputs the orthogonal component element signal to the mixer 105. On the other hand, the channelization code generation circuit 104 outputs the channelization code signal to the mixer 105, and the mixer 105 mixes the channelization code signal with the orthogonal component element signal, and modulates the channelization orthogonal component element signal. Output to 106. Further, the frame clock generation circuit 103 converts the frame clock signal into the modulation circuit 1
06 is output. Modulating circuit 106 modulates the frame clock signal using the channelized quadrature component signal,
The modulation-coded channelized frame clock signal is output to the pulse generation circuit 107. Pulse generation circuit 107
Generates an electrical monocycle pulse triggered by the modulation-coded channelized frame clock signal. The generated electric monocycle pulse is sent to a transmitting antenna 108, which converts the electric monocycle pulse into an electromagnetic pulse and transmits it as a radiation signal to a receiving device via a propagation medium such as air. Sent.

The configuration examples shown in FIGS. 1 to 3 are as follows.
This is shown as an example, and the configuration of the transmitter according to the present embodiment is not intended to be limited to these.

[Exemplary Configuration of Receiver] Next, an exemplary configuration of a receiving apparatus that receives and demodulates a radiation signal transmitted from the transmitting apparatus according to the present embodiment will be described with reference to FIG. FIG. 4 is a block diagram illustrating a configuration example of the receiving apparatus according to the present embodiment.

The receiving apparatus according to the present embodiment has a receiving antenna 408 for receiving a transmitted radiation signal, and the received signal is sent from the receiving antenna 408 to the primary demodulation circuit 406.

The primary demodulation circuit 406 performs a demodulation process corresponding to the modulation method executed by the modulation circuit 106 of the transmitting device.

On the other hand, the receiving apparatus according to this embodiment has a frame clock generating circuit 403, and a frame substantially equivalent to the frame clock (monocycle pulse) generated by the frame clock generating circuit 103 of the transmitting apparatus. Generate a clock signal. The frame clock generation circuit 403 outputs the frame clock signal to the mixer 405. Further, the receiving device is a decoding code generation circuit 40.
4, the decode code generation circuit 404 generates a decode control signal corresponding to the channelization code used by the channelization code generation circuit 104 of the transmitting apparatus, and outputs this to the mixer 405.

The mixer 405 is the mixer 105 of the transmitting device.
It performs processing corresponding to the processing operation of, for example,
If the mixer 105 of the transmitting device performs the delay, the mixer 405 is also configured to perform the delay. Mixer 40
5 sends its output to the pulse generation circuit 407.

The pulse generation circuit 407 generates a monocycle pulse using the output of the mixer 405 as a trigger,
This is sent to the primary demodulator 406.

The primary demodulation circuit 406 performs a demodulation process corresponding to the modulation method executed by the modulation circuit 106 of the transmission device using the monocycle pulse obtained from the pulse generation circuit 407, and receives the radiation signal. From the orthogonal component element inverse mapping circuit 4
02 is output.

The orthogonal component element inverse mapping circuit 407 has the same orthogonal component element group as the orthogonal component element group used by the orthogonal component element selection circuit 102 of the transmitting apparatus. A correlation is obtained between the component element signal and each of the orthogonal component elements of the orthogonal component element group, and an information signal corresponding to the orthogonal component element having the maximum correlation value is output.

[0049]

[Table 2] Table 2 above shows an example in which the orthogonal component inverse mapping circuit 402 inverse maps the orthogonal component to an information signal.

In this example, the orthogonal code sequences “0000”, “0011”, and “010”, which are the same four orthogonal component elements as the orthogonal component element group listed in Table 1 above, are used.
1 "and" 0110 "are used.

These orthogonal component elements are respectively associated with 2-bit signals “00”, “01”, “10”, and “11” to be output.
Calculates the correlation value between the received orthogonal component element signal and each of the four orthogonal component elements, and generates an output signal associated with the orthogonal component element that has obtained the highest correlation value. For example, if the received quadrature component signal is "0
If it is "101", the orthogonal component element "0101" having the highest correlation with this is selected, and the corresponding output signal "10" is output. As a result, the transmitted information signal “10” is restored as the output signal “10” in the receiving device.

[Second Embodiment] Next, a second embodiment according to the present invention will be described with reference to FIGS.

[Exemplary Configuration of Transmitting Apparatus] FIG. 5 is a block diagram showing an exemplary configuration of the transmitting apparatus according to the second embodiment of the present invention.

The transmitting device has an information signal source 501.
Serial / parallel conversion circuit 502 connected to information signal source 501
C, a sequence code generation circuit 502A, a selection circuit 502B connected to the sequence code generation circuit 502A and the serial / parallel conversion circuit 502C, and an exclusive OR circuit connected to the selection circuit 502B and the series / parallel conversion circuit 502C. 5
09, the frame clock generation circuit 503, the channelization code generation circuit 504, and the frame clock generation circuit 5
03, a delay circuit 505 connected to the channelization code generation circuit 504, a delay circuit 505, a second delay circuit 506 connected to the exclusive OR circuit 509, and a delay circuit 506 connected to the second delay circuit 506. And a pulse generation circuit 507.

The information signal source 501 generates an information signal to be transmitted by the transmission device, and converts the information signal into a serial / parallel conversion circuit 502.
Supply to C. The information signal is a digital signal representing voice, data, image, or the like.

The serial / parallel conversion circuit 502C converts the information signal, which is a serial signal supplied from the information signal source 501, into a parallel signal and supplies the parallel signal to the selection circuit 502B. In this configuration example, it is assumed that an information signal composed of k bits is converted in parallel as the information signal and supplied to the selection circuit 502B.

The sequence code generation circuit 502A stores M code sequences orthogonal to each other, and supplies the code sequence selected by the selection circuit 502B to the selection circuit. Where M =
It is assumed that the number is 2k, and M kinds of information represented by k bits and M code sequences are associated with each other in a one-to-one correspondence. In this embodiment, a Walsh sequence is used as the code sequence.
The present invention is not limited to the alsh sequence, and can be realized by using other orthogonal sequences.

The selection circuit 502B includes a serial / parallel conversion circuit 5
According to the k-bit parallelized information signal to be supplied from 02C, a corresponding code sequence is selected, and the signal of the selected code sequence is supplied to the exclusive OR circuit 509. The Walsh sequence selected by the selection circuit 502B is the i-th Walsh code sequence of the M Walsh sequences of the e-th user, and the j-th value (1 or 0) of the code sequence is expressed by the following equation (1). 1)

(Equation 1) It is represented by

On the other hand, the serial-to-parallel conversion circuit 502C outputs the next 1-bit data (represented by the following equation (2)) of the k-bit information signal supplied in parallel to the selection circuit 502B.

(Equation 2) Is supplied to the exclusive OR circuit 509. The exclusive OR circuit 509 that receives the signal calculates the following equation (3).

(Equation 3) And outputs the output signal to the second delay circuit 5
06.

On the other hand, in the transmission device, the frame clock generation circuit 503 generates a frame clock signal SG101 having a pulse interval (period) Tf, and supplies this to the delay circuit 505. As in the first embodiment, the frame clock signal is a monocycle pulse,
For example, it is preferable to use a pulse having a pulse interval of 25 to 1000 nanoseconds and a pulse width of 0.2 to 1.50 nanoseconds.

FIG. 6 shows a waveform diagram of the frame clock signal SG101 output from the frame clock generation circuit 503. As shown in the figure, a pulse train of pulses P is output at a pulse interval Tf. This pulse train is expressed by the following equation (4).

(Equation 4) It expresses.

On the other hand, the channelization code generation circuit 504
A channelization code uniquely determined for each transmission device is generated and supplied to the delay circuit 505 as a channelization code signal. The channelization code is a code sequence orthogonal to the channelization code of another transmission device, and for example, a PN code sequence is used. The j-th value of this channelization code is c
j.

The delay circuit 505 delays the pulse of the frame clock signal by using the channelization code.

(Equation 5) Output signal SG102 of delay circuit 505 represented by
And supplies the same to the second delay circuit 506.

FIG. 7 shows a waveform diagram of signal SG102 output from delay circuit 505. As shown in the figure, each pulse P is compared with the signal generated by the frame clock generation circuit by the following equation (6).

(Equation 6) Only a delay TD1 has been added.

Next, the second-order delay circuit 506 outputs the output signal SG102 of the delay circuit 505 to the exclusive-OR circuit 5.
09 and the output signal SG103
Is generated and supplied to the pulse generation circuit 507.

The output signal SG103 is represented by the following equation (7).

(Equation 7)

FIG. 8 is a waveform diagram of the output signal SG103.
Shown in Each pulse P is output from the frame clock generation circuit 503.
Are delayed by the delay amount TD2 represented by the following equation (8).

(Equation 8)

The pulse generation circuit 507 outputs the output signal SG1
03 as an electrical monocycle pulse SG
Generate 104. Electrical monocycle pulse SG1
04 is the following equation (9)

(Equation 9) Can be represented by FIG. 9 shows a waveform diagram of the electric monocycle pulse SG104.

The generated electric monocycle pulse SG104 is sent to a transmitting antenna (not shown), and the transmitting antenna converts the electric monocycle pulse into an electromagnetic pulse, and outputs a radiation signal through a propagation medium such as air. To the receiving device. This radiated signal becomes a wide band signal or an ultra wide band signal, and enables communication that is more resistant to multi-path and fading as compared with conventional spread spectrum (SS) communication and that realizes a higher transmission rate. Further, according to the transmission apparatus according to the present embodiment, the transmission rate is relatively improved by performing multi-level coding using orthogonal component elements, and it is possible to cope with a multi-user environment by using a channelized code sequence. Is possible.

[Configuration Example of Receiving Apparatus] Next, a configuration example of the receiving apparatus according to the present embodiment will be described with reference to FIGS.
3 will be described. FIG. 10 is a block diagram illustrating a configuration example of a receiving apparatus according to the present embodiment.

The receiving apparatus according to the present embodiment has a receiving antenna 1008 for receiving a transmitted radiation signal.
And the received signal r (t) is given by the following equation (1).
0).

(Equation 10) This signal r (t) is sent from reception antenna 1008 to correlation circuit 1006.

On the other hand, the receiving apparatus according to the present embodiment has a frame clock generating circuit 1003, and a frame substantially equivalent to the frame clock (monocycle pulse) generated by the frame clock generating circuit 503 of the transmitting apparatus. A clock signal SG201 is generated. The frame clock signal SG201 is calculated by the following equation (11).

[Equation 11] Is represented by In Expression (11), τ1 indicates a delay time due to signal propagation between the transmitting and receiving devices. ΔD is a value determined by the time width of the pulse. Note that FIG.
5 shows a waveform diagram of the frame clock signal SG201.

The frame clock generation circuit 1003 converts the frame clock signal SG201 into a delay circuit 1005
Output to Further, the receiving device is a sequence code generation circuit 100.
4, the sequence code generation circuit 1004 generates a sequence code signal cj corresponding to the channelization code used by the channelization code generation circuit 504 of the transmission device, and outputs this to the delay circuit 1005.

The delay circuit 1005 delays the pulse P of the frame clock signal SG201 using the sequence code signal cj, and obtains the following equation (12).

(Equation 12) Then, an output signal SG202 represented by the following formula is generated and supplied to the transmission waveform circuit 1007. In equation (11), Tc indicates a delay amount provided by the delay circuit 1005. FIG. 12 shows a waveform diagram of the output signal SG202 of the delay circuit 1005. In the figure, it is shown that each pulse is delayed by TD3 = cjTc as compared with the time when the pulse was generated by the frame clock generation circuit 1003.

The pulse generation circuit 507 outputs the output signal SG2
02 as a trigger, electrical monocycle pulse SG
203 is generated. Electric monocycle pulse SG2
03 is the following equation (13)

(Equation 13) Can be represented by FIG. 13 shows a waveform diagram of the electric monocycle pulse SG203. In the figure, each pulse P is applied to a frame clock generation circuit 10.
It is shown that the time is delayed by TD3 = cjTc compared to the time point generated by C.03.

The correlation circuit 1006 outputs the output signal SG203
And the received signal r (t) is correlated to output an output signal αj. The output signal αj is represented by the following equation (14).

[Equation 14] The output signal αj is sent to the correlator aggregate 1002A.
The correlator aggregate 1002A includes M correlators 1002a to 1002a.
1002 m, each correlator is a sequence obtained by converting 0 of the Walsh sequence used on the transmission side to −1, Cwals
h (i, j) are stored, and a correlation value with each output signal αj is calculated, and this is output to the maximum value selection circuit 1002B.

The maximum value selection circuit 1002B determines the one having the maximum absolute value from the following equation (14) calculated by the correlator aggregate 1002A, and supplies the maximum value to the sign determination circuit 1002C. I do. Sign determination circuit 1
002C further determines whether the maximum value is positive or negative.

Thereafter, the receiving apparatus obtains and outputs a k-bit output signal corresponding to the Walsh code sequence from which the maximum correlation value has been obtained, by an inverse mapping circuit (not shown). This allows
The transmitted information signal is restored as an output signal in the receiving device.

[Evaluation of Performance] Finally, the result of evaluating the performance of the method according to the present invention by calculation simulation will be described.

[Theoretical Values and Simulation Results of Conventional Ultra Wideband System] Before performance evaluation of the proposed system, a simulation of the conventional system was made and compared with the theoretical values. The specifications are shown in Table 3 below, and the results are shown in FIG.

[Table 3] In FIG. 14, the SNR is plotted on the horizontal axis and the BER is plotted on the vertical axis. The theoretical value is

(Equation 15) Asked. This result confirms that the theoretical value and the simulation value are almost the same.

[Simulation of Proposed System] In the conventional system, it is sufficient to judge whether the output result is + or-. However, in the system according to the present invention, a plurality of bits are transmitted at the same time, and all the sequences are correlated on the receiving side. It is necessary to determine whether the correlation value with the series is maximum. Therefore, the BER naturally becomes worse in the method according to the present invention even when compared at the same S / N. Therefore, the BER was compared with Eb / No in order to compare under a fair condition. The specifications are shown in Table 4 below.

[Table 4] Here, since the number of bits transmitted simultaneously in one symbol is 6 bits, the pulse repetition time is increased by 60 times to 60 ns in order to equalize the transmission rate, and conversely, the pulse repetition time of the conventional method is reduced. The simulation is performed for the case where the ratio is reduced to 1/6. Figure 1 shows the results.
It is shown in FIG. From these results, when the BER is compared with 10-3, a gain of about 3 dB is obtained for one user and about 4 dB for 30 users, and even if the transmission speed is increased, the characteristics of the system according to the present invention are lower than those of the conventional system. Is small.

[Optimal value of pulse repetition number of proposed method] In the conventional method, the SNR does not change even if the pulse repetition number is changed under the condition of a constant transmission rate. However, if the number of pulse repetitions is too large, the pulse repetition rate becomes small, and the rule deteriorates. On the other hand, in order to increase the number of pulse repetitions under the condition of a constant transmission rate in the proposed method, it is necessary to determine Tf such that NsTf / m = constant if the number of bits transmitted simultaneously in one symbol is m. Here, Ns = 2m-1. In the M-ary, if the number of bits transmitted simultaneously is k bits, the transmission speed is K times higher with the same processing gain. Conversely, if the transmission speed is the same, the processing gain can be suppressed to 1 / k. For this reason, in the method according to the present invention, the characteristics are improved as the number of pulse repetitions is increased. However, if the number of pulse repetitions Ns is increased, the pulse repetition time Tf becomes shorter under the condition of a constant transmission rate, and if this Tf becomes too short, Nh becomes smaller in consideration of the pulse width, so that NhTc / Tf becomes smaller. Then, the characteristics deteriorate because the inter-station interference is not approximated to the Gaussian distribution. Therefore, there should be an optimal value for the number of pulse repetitions. Therefore, Eb / No is 5d
B was fixed to B, and the BER characteristics when the number of pulse repetitions was changed were examined by simulation.

First, a simulation was performed using the conventional method. Table 5 below shows the simulation data.

[Table 5] FIG. 16 shows a simulation result.

Assuming that interference between other stations is approximated to a Gaussian distribution in the conventional system, the characteristics do not change even if the number of pulse repetitions is changed under the constant transmission rate condition. However, when the number of pulse repetitions is increased under the condition of a constant transmission rate, NhTc / T
f becomes small, interference between other stations cannot be approximated to a Gaussian distribution, and the characteristics deteriorate. The simulation results show that the characteristics do not deteriorate when the number of pulse repetitions is about 100 or less, but that the characteristics start to deteriorate around 100 or more.

Next, a similar simulation was performed by the proposed method. Table 6 below shows the specifications of the simulation.

[Table 6] FIG. 17 shows a simulation result. The results show that the characteristics improve as the number of pulse repetitions increases. In this evaluation, the number of pulse repetitions was 21
At this point, the sequence length was 210
= 1024 Walsh sequences are required, and it is difficult to investigate further by simulation. Also,
The circuit scale also increases.

[Evaluation Results] In this evaluation, in the method according to the present invention, when the BER was 10-3, a gain of about 3 dB was obtained when the Eb / No was 30 users, and a gain of about 4 dB was obtained when the Eb / No was 60 users. Further, the optimum value of the number of pulse repetitions of the method according to the present invention was obtained by simulation, and it was found that the gain was obtained as the number of pulse repetitions was increased.

[0087]

According to the present invention, the transmission speed is not reduced,
In addition, by increasing the pulse interval without reducing the number of pulses, it is possible to eliminate interference at the same time while achieving high quality and high transmission rate, and by using a code indicating information for multiple access and M-ary, It is possible to realize a transmission system that solves the problem of using a large number of codes such as / SSMA modulation.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a transmission device according to a first embodiment.

FIG. 2 is a block diagram illustrating another configuration example of the transmitting apparatus according to the first embodiment.

FIG. 3 is a block diagram illustrating still another configuration example of the transmission device according to the first embodiment.

FIG. 4 is a block diagram illustrating a configuration example of a receiving apparatus according to the first embodiment.

FIG. 5 is a block diagram illustrating a configuration example of a transmission device according to a second embodiment;

FIG. 6 is an output waveform diagram of the frame clock generation circuit according to the second embodiment;

FIG. 7 is an output waveform diagram of the delay circuit according to the second embodiment.

FIG. 8 is an output waveform diagram of a second delay circuit according to the second embodiment.

FIG. 9 is an output waveform diagram of the pulse generation circuit according to the second embodiment.

FIG. 10 is a block diagram illustrating a configuration example of a receiving apparatus according to a second embodiment.

FIG. 11 is a waveform chart of the receiving apparatus according to the second embodiment.

FIG. 12 is a waveform chart of the receiver according to the second embodiment.

FIG. 13 is a waveform chart of the receiving device according to the second embodiment.

FIG. 14 is a diagram showing a simulation and a theoretical value of an ultra wide band.

FIG. 15 is a diagram showing BER characteristics of a conventional system and a system according to the present invention.

FIG. 16 is a diagram showing a simulation result when the number of pulse repetitions is changed.

FIG. 17 is a diagram showing BER characteristics of the system according to the present invention when the number of pulse repetitions is changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 ... Information signal source 102 ... Orthogonal component element selection circuit 103 ... Frame clock generation circuit 104 ... Channelization code generation circuit 105 ... Mixer 106 ... Modulation circuit 107 ... Pulse generation circuit 108 ... Transmission antenna 402 ... Orthogonal component inverse mapping circuit 403 ... frame clock generation circuit 404 ... channelization code generation circuit 405 ... mixer 406 ... primary demodulation circuit 407 ... pulse generation circuit 408 ... receiving antenna

Continued on the front page F term (reference) 5K022 EE01 EE21 EE31 5K029 AA03 AA11 BB03 GG03 5K041 AA01 BB08 EE00 FF21 FF32 5K047 AA15 BB01 EE04 MM02 MM11

Claims (28)

[Claims] 1. An information signal is converted into at least one of a plurality of orthogonal component elements orthogonal to each other, and the converted orthogonal component element is modulated using at least one of a frame clock signal and a channelization code signal. A transmission device, characterized by the above. 2. An orthogonal component element selection circuit for selecting at least one orthogonal component element from a plurality of orthogonal component elements orthogonal to each other according to an information signal; a frame clock generation circuit for generating a frame clock signal; A channelization code generation circuit for generating a code signal; a mixer connected to the frame clock generation circuit and the channelization code generation circuit for mixing and outputting the frame clock signal and the channelization code signal; A modulation circuit for modulating an output of a mixer by the at least one orthogonal component element selected by an element selection circuit. 3. The transmission apparatus according to claim 2, wherein the plurality of orthogonal component elements are a plurality of code sequences that are orthogonal to each other. 4. The transmission device according to claim 2, wherein the mixer adds a delay according to a channelization code signal to a frame clock signal, and the modulation circuit performs a modulation according to the at least one orthogonal component element. And performing time position modulation on a frame clock signal delayed according to a channelized code signal. 5. A quadrature component selection circuit for selecting at least one quadrature component from a plurality of quadrature components orthogonal to each other according to an information signal; a frame clock generation circuit for generating a frame clock signal; A modulation circuit connected to an element selection circuit and a frame clock generation circuit, for modulating a frame clock signal by the at least one orthogonal component element selected by the orthogonal component element selection circuit; and a channelization for generating a channelization code signal. A code generation circuit, a mixer connected to the modulation circuit and the channelization code generation circuit, and mixing and outputting the frame clock signal modulated by the at least one orthogonal component element and the channelization code signal; A transmission device comprising: 6. The transmitting apparatus according to claim 5, wherein the plurality of orthogonal component elements are a plurality of code sequences that are orthogonal to each other. 7. The transmission device according to claim 5, wherein the modulation circuit performs time position modulation on a frame clock signal according to the at least one orthogonal component element, and the mixer performs the time position modulation. A transmission device for adding a delay according to the channelized code signal to the frame clock signal. 8. An orthogonal component element selection circuit for selecting at least one orthogonal component element from a plurality of orthogonal component elements orthogonal to each other according to an information signal; a channelization code generation circuit for generating a channelization code signal; A mixer connected to the orthogonal component element selection circuit and the channelization code generation circuit, for mixing and outputting the at least one orthogonal component element and the channelization code signal; and a frame clock generation circuit for generating a frame clock signal. And a modulation circuit connected to the mixer and the frame clock generation circuit, and modulating the frame clock signal according to the output of the mixer. 9. The transmitting apparatus according to claim 8, wherein the plurality of orthogonal component elements are a plurality of code sequences that are orthogonal to each other. 10. The transmission device according to claim 8, wherein the modulation circuit performs time position modulation on a frame clock signal according to the at least one orthogonal component element, and the mixer performs the time position modulation. A transmission device for adding a delay according to the channelized code signal to the frame clock signal. 11. A serial-to-parallel conversion circuit for receiving an information signal, converting the k-bit information signal into parallel and outputting the same, and outputting an information signal of the (k + 1) th bit following the k-bit, A sequence code generation circuit capable of generating a code sequence; and a selection circuit connected to the sequence code generation circuit and the serial / parallel conversion circuit, wherein at least one of the plurality of code sequences is determined according to the received k-bit information signal. And a selection circuit for receiving and outputting the selected code sequence from the sequence code generation circuit, an exclusive logic of the selected at least one code sequence and the information signal of the (k + 1) th bit connected to the selection circuit and the serial / parallel conversion circuit. An exclusive OR circuit that outputs a sum signal, a frame clock generation circuit that generates a frame clock signal, and a channel that generates a channelized code signal A first delay circuit that is connected to the frame code generation circuit, the frame clock generation circuit, and the channelization code generation circuit, and that delays and outputs the frame clock signal in accordance with the channelization code signal; A delay circuit and the exclusive OR circuit,
A second delay circuit for adding a delay according to an output of the exclusive OR circuit to the delayed frame clock signal. 12. A quadrature component element included in a radiation signal or a component corresponding thereto is extracted using a frame clock signal and a channelization code signal used by a transmission device,
A receiving apparatus for calculating a correlation value between the extracted orthogonal component element or a component corresponding thereto and each of a plurality of orthogonal component elements used by a transmitting apparatus. 13. A frame clock generation circuit for generating a frame clock signal substantially the same as a frame clock signal used by a transmission device, and a decode control signal corresponding to a channelization code used by the transmission device are generated and output. A mixer for receiving a frame clock signal and a decode control signal, mixing and outputting these, and a mixer connected to the mixer, A pulse generating circuit for generating a monocycle pulse by using the output of the device as a trigger and transmitting the monocycle pulse to a primary demodulator; receiving a radiation signal from a transmitting device; And a primary demodulator for extracting the quadrature component from the radiation signal and a primary demodulation circuit, A correlator aggregate for receiving the obtained orthogonal component element signal and calculating a correlation value between a plurality of predetermined orthogonal component elements and the extracted orthogonal component element; and a correlator aggregate connected to the correlator aggregate. A maximum value selection circuit that determines an orthogonal component element that has obtained the maximum correlation value from the correlation value calculated by the body. 14. A frame clock generation circuit for generating a frame clock signal substantially the same as a frame clock signal used by a transmission device, and a sequence code generation for generating a sequence code corresponding to a channelization code used by the transmission device. A delay circuit that is connected to the circuit, the frame clock generation circuit and the sequence code generation circuit, and adds a delay to the frame clock signal in accordance with the sequence code; and a delay circuit that is connected to the delay circuit and uses the delayed frame clock signal as a trigger to generate a pulse train. A transmission waveform circuit to be generated, a correlation circuit that receives a radiation signal from the transmission device and is connected to the transmission waveform circuit, and calculates a correlation between the radiation signal and the pulse train. Have a plurality of orthogonal code sequences, and the output of the correlation circuit and each of the plurality of orthogonal code sequences A correlator aggregate for calculating a correlation value; a maximum value selection circuit connected to the correlator aggregate for selecting a maximum correlation value from the correlation values output by the correlator aggregate; A receiving apparatus comprising: a sign determination circuit that determines whether the sign is positive or negative. 15. A step of converting a certain information signal into at least one of a plurality of orthogonal component elements orthogonal to each other, and modulating the converted orthogonal component element using at least one of a frame clock signal and a channelization code signal. A transmitting method. 16. A step of selecting at least one orthogonal component element from a plurality of orthogonal component elements orthogonal to each other in accordance with an information signal; a step of mixing and outputting a frame clock signal and a channelization code signal; Modulating the output obtained by said mixing and outputting step with at least one selected orthogonal component element. 17. The transmission method according to claim 16, wherein the plurality of orthogonal component elements are a plurality of code sequences that are orthogonal to each other. 18. The transmission method according to claim 16, wherein the step of mixing and outputting is a step of adding a delay according to a channelization code signal to a frame clock signal, and the step of modulating includes: Transmitting a time position modulation to the frame clock signal delayed according to the channelized code signal in accordance with the at least one orthogonal component element. 19. A step of selecting at least one orthogonal component element from a plurality of orthogonal component elements orthogonal to each other in accordance with an information signal; a step of generating a frame clock signal; Modulating a frame clock signal by an element; generating a channelized code signal; mixing the frame clock signal modulated by the selected at least one orthogonal component element with the channelized code signal. And transmitting the data. 20. The transmission method according to claim 19, wherein the plurality of orthogonal component elements are a plurality of code sequences that are orthogonal to each other. 21. The transmission method according to claim 19, wherein the modulating step is a step of performing time-position modulation on a frame clock signal according to the at least one orthogonal component element. Adding a delay according to the channelization code signal to the time position modulated frame clock signal. 22. A step of selecting at least one orthogonal component element from a plurality of orthogonal component elements orthogonal to each other according to an information signal; a step of generating a channelized code signal; A step of mixing and outputting the component elements and the channelized code signal; a step of generating a frame clock signal; and a step of modulating the frame clock signal according to the output obtained by the mixing step. A transmitting method. 23. The transmission method according to claim 22, wherein the plurality of orthogonal component elements are a plurality of code sequences that are orthogonal to each other. 24. The transmission method according to claim 22, wherein the modulating step is a step of performing time position modulation on a frame clock signal according to the selected at least one orthogonal component element; Transmitting the time position modulated frame clock signal with a delay according to a channelization code signal. 25. A step of receiving an information signal, converting and outputting the k-bit information signal in parallel, and outputting an (k + 1) -th bit information signal following the k-bits, from a plurality of code sequences orthogonal to each other. Selecting at least one of the plurality of code sequences according to the received k-bit information signal; and the selected at least one code sequence and the k + 1
Outputting an exclusive OR signal with the information signal of the bit; generating a frame clock signal; generating a channelized code signal; delaying the frame clock signal according to the channelized code signal And a second delay step of adding a delay according to the exclusive OR signal to the delayed frame clock signal. Method. 26. A step of extracting a quadrature component element or a component corresponding to the quadrature component element contained in a radiation signal using a frame clock signal and a channelization code signal used by a transmitting apparatus; Obtaining a correlation value between a corresponding component and each of a plurality of orthogonal component elements used by the transmitting apparatus. 27. A method for generating a frame clock signal substantially the same as a frame clock signal used by a transmitting device, generating a decode control signal corresponding to a channelization code used by a transmitting device, Receiving a signal and a decode control signal, mixing and outputting them, generating a monocycle pulse using the output obtained by the mixing and outputting step as a trigger, and radiating a signal from the transmitting device. Receiving the quadrature component transmitted from the radiation signal using the monocycle pulse, and receiving the extracted quadrature component signal and extracting a predetermined plurality of quadrature components. Calculating a correlation value with the calculated orthogonal component element; and calculating a quadrature component that has obtained a maximum correlation value from the calculated correlation value. Determining the element. 28. A step of generating a frame clock signal that is substantially the same as a frame clock signal used by the transmitting apparatus, a step of generating a sequence code corresponding to the channelization code used by the transmitting apparatus, Adding a delay to the frame clock signal accordingly; generating a pulse train using the delayed frame clock signal as a trigger; receiving a radiation signal from a transmitting device and calculating a correlation between the radiation signal and the pulse train And a plurality of orthogonal code sequences used by the transmitting device,
Calculating a correlation value between the output of the correlation circuit and each of the plurality of orthogonal code sequences; selecting a maximum correlation value from the calculated correlation values; and determining whether the selected maximum value is positive or negative. And a receiving method.