UWB communication system

Abstract

To provide a radio communication system for mitigating collisions or interference that may occur among UWB data packets transmitted from different systems or devices, in environment in which a plurality of systems or devices using UWB are mixed.SOLUTION: A UWB communication system includes: means for informing a UWB physical layer and a narrow bandwidth physical layer cooperatively operates with the UWB physical layer of a task request signal for requesting tasks from a MAC layer; determination means for determining a clear channel using either of energy detection by the narrow bandwidth physical layer to which the task request signal has been informed, CSMA or CSMA / CA; report notification means for informing of a clear channel report according to the clear channel determination; command signal notification means for notifying the UWB physical layer and the narrow bandwidth physicals layer of a command signal from the MAC layer according to the clear channel report; and means for transmitting a pilot narrow bandwidth signal indicating execution of UWB communication using the narrow bandwidth physical layer and transmitting the UWB signal from the UWB physical layer.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a UWB communication system for reducing collisions and interference that may occur between UWB data packets transmitted from different systems and devices in an environment where a plurality of systems and devices using UWB (Ultra Wide Band) coexist.

Background Art

[0002] Since UWB has features such as low power consumption, a simple circuit, and high time resolution, its application to high-precision ranging and positioning, radar, and short-range communication is being promoted. To support these various applications, a plurality of international standards using UWB have been established by Working Group 15 (WSN; Wireless Specialty Networks) under the IEEE802 Standardization Committee of the International Organization for Standardization. In addition, smartphones, smartwatches, and keyless access systems for cars equipped with UWB chips have been commercialized and are on the market.

[0003] However, during UWB communication, if a UWB packet is transmitted from a device not related to the UWB communication, there is a possibility that it will collide with the packet during the UWB communication. Therefore, as the number of systems and devices using UWB increases, the probability of causing collisions and interference between UWB packets transmitted from various systems and devices may increase. For this reason, media access technologies for reducing collisions and interference that may occur between UWB data packets transmitted from different systems and devices as shown in Non-Patent Documents 1 and 2 and Patent Document 1 have attracted attention.

[0004] In Non-Patent Document 1, a media access technology that defines ALOHA as the media access method for UWB is disclosed. Also, in Non-Patent Document 2, a media access technology is disclosed in which CCA (Clear Channel Assessment) based on sensing for the preamble of UWB packets is added. Further, in Patent Document 1, a method of coordinating a central wireless device and its peripheral devices as one group and accessing time slots as a medium is disclosed.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the ALOHA method used in Non-Patent Document 1, since the UWB device can always freely access the time slot when the medium is in the idle state, as the number of systems and devices using UWB increases, the probability of collision between UWB packets continuously increases. Further, in Non-Patent Document 2, in addition to the ALOHA method, CCA based on sensing of the preamble of the packet is defined, but there are problems such that the receiver becomes complicated or the detection time becomes long to detect the preambles of different UWB methods. Further, in Patent Document 1, one UWB central wireless device and a plurality of UWB peripheral wireless devices are grouped together as one group, and access to the time slot is coordinated with the UWB central wireless device as the center. Therefore, it is impossible to avoid data packet collision or interference between UWB devices outside the group or with other groups.

[0008] Therefore, the present invention has been devised in view of the above-described problems, and an object thereof is to provide a UWB communication system for reducing collisions and interference that may occur between UWB data packets transmitted from different systems and devices in an environment where a plurality of systems and devices using UWB coexist.

Means for Solving the Problems

[0009] The UWB communication system according to the first invention is a UWB communication system that performs UWB communication based on a UWB physical layer using UWB (Ultra Wide Band) communication, at least one narrowband physical layer that cooperates with the UWB physical layer, and a MAC (Media Access Control) layer that manages the UWB physical layer and the narrowband physical layer. The UWB communication system includes: a request notification means for notifying a communication request signal for requesting UWB communication from the MAC layer to the UWB physical layer and the narrowband physical layer; a determination means for determining an available channel for the UWB communication by using any one of energy detection, CSMA (Carrier Sense Multiple Access), or CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) by the narrowband physical layer notified of the communication request signal; a report notification means for notifying a clear channel report indicating the result of the determination by the determination means from the narrowband physical layer to the MAC layer based on the determination by the determination means; a command notification means for notifying a command signal for the UWB communication from the MAC layer to the UWB physical layer and the narrowband physical layer in response to the clear channel report notified by the report notification means; and a communication means for transmitting a pilot narrowband signal indicating the execution of the UWB communication by using the narrowband physical layer notified of the command signal by the command notification means, and performing the UWB communication by using the UWB physical layer notified of the command signal by the command notification means.

[0010] The UWB communication system according to the second invention is the UWB communication system according to the first invention, wherein the communication means is characterized in that the transmission of the pilot narrowband signal and the UWB communication are started simultaneously.

[0011] The UWB communication system according to the third invention is the UWB communication system according to the second invention, wherein the communication means is characterized in that the transmission of the pilot narrowband signal and the UWB communication are ended simultaneously.

[0012] The UWB communication system according to the fourth invention, in the first invention, is characterized in that the communication means starts the UWB communication after starting the transmission of the pilot narrowband signal.

[0013] The UWB communication system according to the fifth invention, in any one of the first to fourth inventions, is characterized in that the communication means transmits the pilot narrowband signal composed of a plurality of narrowband signals with different preset frequencies according to the channel for the UWB communication.

[0014] The UWB communication system according to the sixth invention, in any one of the first to fourth inventions, is characterized in that the communication means transmits the pilot narrowband signal composed of a plurality of narrowband signals with different preset frequencies according to the time for the UWB communication.

Advantages of the Invention

[0015] According to the first to sixth inventions, by introducing the cooperative operation between the UWB physical layer and the narrowband physical layer and associating the transmission of the pilot narrowband signal with the UWB communication, in the determination of the available channel, a pilot narrowband signal that is relatively easy to perform CCA such as CSMA / CA, CSMA, or energy detection can be used as a reference signal for substitution. In addition, the mutual interference of UWB signals emitted from different wireless devices can be reduced based on the CCA result for the pilot narrowband signal. Thereby, in an environment where a plurality of systems and devices using UWB coexist, collisions and interferences that may occur between UWB data packets transmitted from different systems and devices can be reduced.

[0016] In particular, according to the second invention, the communication means starts the transmission of the pilot narrowband signal and the UWB communication simultaneously. Therefore, the transmission of the pilot narrowband signal and the execution of the UWB communication in the UWB physical layer can be synchronized. As a result, it becomes possible to equivalently detect the presence or absence of the execution of UWB communication with higher accuracy by CSMA / CA, CSMA, or energy detection for the pilot narrowband signal.

[0017] In particular, according to the third invention, the communication means simultaneously terminates the transmission of the pilot narrowband signal and the UWB communication. Thereby, the start and end of the transmission of the pilot narrowband signal and the UWB communication are synchronized. As a result, it becomes possible to equivalently detect the presence or absence of the execution of UWB communication with higher accuracy by means such as CSMA / CA, CSMA, or energy detection for the pilot narrowband signal.

[0018] In particular, according to the fourth invention, the communication means performs UWB communication after transmitting a pilot narrowband signal. By predetermining the time interval between the pilot narrowband signal and the UWB communication, it is possible to determine that UWB communication is executed after the reception of the pilot narrowband signal. As a result, it becomes possible to equivalently detect the presence or absence of the execution of UWB communication with higher accuracy by means such as CSMA / CA, CSMA, or energy detection for the pilot narrowband signal.

[0019] In particular, according to the fifth invention, the communication means transmits a pilot narrowband signal composed of a plurality of narrowband signals having different preset frequencies according to the channel for UWB communication. Therefore, it is possible to distinguish from narrowband signals transmitted from other narrowband wireless devices using the same frequency band. Also, since the patterns of a plurality of narrowband frequencies correspond to the channel for UWB communication, it becomes possible to determine the channel for UWB communication by determining the patterns of the plurality of narrowband frequencies.

[0020] In particular, according to the sixth invention, the communication means transmits a pilot narrowband signal composed of a plurality of narrowband signals having different preset frequencies according to the time for UWB communication. Therefore, since the patterns of a plurality of narrowband frequencies correspond to the time of UWB communication, it becomes possible to determine the communication time of UWB communication by determining the patterns of the plurality of narrowband frequencies.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

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Figure 7

Mode for Carrying Out the Invention

[0022] Hereinafter, an embodiment of a wireless communication system including the UWB communication system according to the present embodiment will be described using the embodiment.

[0023] FIG. 1 is a configuration diagram of a wireless communication system 100 including a UWB communication system according to an embodiment. The wireless communication system 100 is a communication system using UWB communication and wireless communication other than UWB communication. As shown in FIG. 1, the wireless communication system 100 includes a wireless communication terminal 1 and a base station 3, and the wireless communication terminal 1 and the base station 3 are connected via a communication line 4. Further, the wireless communication system 100 may include a plurality of wireless communication terminals 1a, 1b, 1c via the communication line 4. Also, UWB communication is generally performed directly between a plurality of wireless communication terminals 1a, 1b, 1c.

[0024] The communication line 4 is, for example, a communication line such as 3G, 4G, 5G, LTE (Long Term Evolution), WiFi (registered trademark), etc.

[0025] The base station 3 serves as a wireless access point between a plurality of wireless communication terminals 1 and serves as an interface between a communication line 4 such as the Internet. That is, the base station 3 serves as a relay means for enabling the wireless communication terminal 1 to transmit and receive data to and from the communication line 4 such as the Internet through this.

[0026] The wireless communication terminal 1 may be a communication terminal equipped with a plurality of wireless communication chips, but is not limited to this, and may be any smartphone, smartwatch, tablet terminal, PC, etc.

[0027] The wireless communication terminal 1 performs UWB communication based on a UWB physical layer which is a physical layer using UWB communication, a narrowband physical layer that cooperates with the UWB physical layer which is a physical layer used to determine the presence or absence of UWB communication, and a MAC layer which is a layer above the UWB physical layer and the narrowband physical layer. The wireless communication terminal 1 may perform communication based on a plurality of UWB physical layers and the narrowband physical layer respectively. Also, the wireless communication terminals 1a, 1b, 1c may perform communication such as UWB communication with each other.

[0028] The functions of the wireless communication terminal 1 are realized by a processor such as a CPU (Central Processing Unit) or MPU (Micro processing Unit) reading a program stored in a storage medium such as an HDD or a non-volatile memory (for example, a flash memory).

[0029] The UWB physical layer performs UWB transmission and reception. Also, the UWB physical layer may perform IR-UWB (Impulse Radio Ultra Wide Band) transmission and reception that uses a pulse signal with a very short time width of about 1 nanosecond and transmits information without using a carrier wave by changing the position or phase of the pulse signal on the time axis.

[0030] A narrowband physical layer that operates in coordination with the UWB physical layer may be, for example, a Pilot-NB PHY that transmits and receives narrowband signals for determining the presence or absence of UWB communication. Further, the narrowband physical layer can also communicate via communication line 4. For example, it may communicate via communication line 4 using wireless communication different from the UWB physical layer, such as 3GPP, WiFi (registered trademark), Bluetooth (registered trademark), LoRa (registered trademark), etc.

[0031] The MAC layer is a higher-level protocol that controls the operations of the UWB physical layer and the narrowband physical layer by sending various commands to them.

[0032] FIG. 2 is a flowchart showing the operation of UWB communication according to an embodiment. Hereinafter, with reference to FIG. 2, the operation of the wireless communication terminal 1 according to this embodiment will be described.

[0033] First, in step S10-1, the wireless communication terminal 1 as a communication requester notifies a communication request signal for requesting UWB communication to the narrowband physical layer that operates in coordination with the UWB physical layer from the MAC layer.

[0034] Next, in step S11-1, the narrowband physical layer that operates in coordination with the UWB physical layer, to which the communication request signal has been notified, determines an available channel (CCA: Clear Channel Assessment) using methods such as energy detection, CSMA (Carrier Sense Multiple Access), or CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance).

[0035] CSMA / CA is a communication method using CSMA that checks whether there is a host currently communicating on the transmission medium before starting communication and starts communication when multiple hosts share the same transmission medium and no other host is currently communicating. For example, when it determines that communication is possible, CSMA / CA further waits for a random time and then transmits data.

[0036] Energy detection is ED (energy detection) that detects the energy of a signal by sensing the spectrogram of the signal on the transmission medium. Energy detection determines whether the channel is idle based on the presence or absence of the detected energy.

[0037] Next, in step S12, if the MAC layer does not receive a clear channel report indicating the determination result even after a preset time has passed, it determines a timeout and terminates the current operation.

[0038] Next, when the MAC layer determines a timeout and terminates the current operation, in step S10-2, it notifies the narrowband physical layer that cooperates with the UWB physical layer from the MAC layer again with a communication request signal.

[0039] Next, in step S11-2, the narrowband physical layer that cooperates with the UWB physical layer notified of the communication request signal determines the available channel again.

[0040] If it can be determined in step S11 that there is an available channel, in step S13, the narrowband physical layer notifies the upper layer such as the MAC layer with a clear channel report.

[0041] Next, in step S14, when the MAC layer receives the clear channel report, it notifies the UWB physical layer and the narrowband physical layer that cooperates with the UWB physical layer with a command signal for UWB communication.

[0042] Next, in step S15, the narrowband physical layer that cooperates with the UWB physical layer notified of the command signal transmits a pilot narrowband signal indicating the execution of UWB communication, and the UWB physical layer notified of the command signal performs UWB communication. At this time, the narrowband physical layer and the UWB physical layer perform cooperative operations. The cooperative operation between the narrowband physical layer and the UWB physical layer refers to an operation in which the preset narrowband physical layer and UWB physical layer operate in conjunction. Hereinafter, an example of the cooperative operation will be described with reference to FIG. 3.

[0043] FIG. 3(a) is a schematic diagram showing the relationship between the pilot narrowband signal P and UWB communication T. FIG. 3(a) shows the presence or absence of the pilot narrowband signal P and UWB communication T at the time on the horizontal axis. For example, as shown in FIG. 3(a), as the above-described cooperative operation, the narrowband physical layer and the UWB physical layer may start transmitting the pilot narrowband signal P and UWB communication T simultaneously. Also, the end of transmission of the pilot narrowband signal P and the end of UWB communication T may be performed simultaneously. In such a case, the transmission of the pilot narrowband signal P and UWB communication T are based on the same clock, and the start and end of the transmission of the pilot narrowband signal P and UWB communication T are synchronized. Therefore, the transmission of the pilot narrowband signal P and the UWB communication T of the UWB physical layer can be synchronized. As a result, it becomes possible to equivalently detect the presence or absence of UWB communication T with higher accuracy by CSMA / CA or energy detection etc. for the pilot narrowband signal P. Also, in order to make the transmission of the pilot narrowband signal and the UWB communication of the UWB physical layer based on the same clock, for example, the narrowband physical layer and the UWB physical layer may use a common oscillator or a common timer.

[0044] Further, FIG. 3(b) is a schematic diagram showing the relationship between the pilot narrowband signal P and the UWB communication T. FIG. 3(b) shows the presence or absence of the pilot narrowband signal P and the UWB communication T at the time on the horizontal axis. As shown in FIG. 3(b), the narrowband physical layer and the UWB physical layer may execute the UWB communication T for a preset time from the start of transmission of the pilot narrowband signal P. Therefore, by detecting the transmission of the pilot narrowband signal P, it is possible to determine that the UWB communication T is executed for the set time. As a result, it becomes possible to equivalently detect the presence or absence of the UWB communication T with higher accuracy by CSMA / CA, CSMA, or energy detection etc. for the pilot narrowband signal P.

[0045] Further, FIG. 3(c) is a schematic diagram showing the relationship between the pilot narrowband signal P and the UWB communication T. FIG. 3(c) shows the presence or absence of the pilot narrowband signal P and the UWB communication T at the time on the horizontal axis. As shown in FIG. 3(c), the narrowband physical layer and the UWB physical layer may perform the UWB communication T after starting the transmission of the pilot narrowband signal P. In such a case, the UWB communication T may be started after a preset time from the start of transmission of the pilot narrowband signal P. In such a case, for example, the UWB communication T may be started simultaneously with the end of transmission of the pilot narrowband signal P, or the UWB communication T may be started after a certain time from the end of transmission of the pilot narrowband signal P. Therefore, it is possible to determine that the UWB communication T is executed after the transmission of the pilot narrowband signal P. As a result, it becomes possible to equivalently detect the presence or absence of the UWB communication T with higher accuracy by CSMA / CA, CSMA, or energy detection etc. for the pilot narrowband signal P.

[0046] The three types of UWB communications (T1, T2, T3) shown in FIGS. 3(a), 3(b), and 3(c) may be different UWB communications by the same wireless communication terminal 1, or may be UWB communications by a plurality of different wireless communication terminals 1. Further, the cooperative operation is not limited to the above-described example, and any operation may be used.

[0047] The pilot narrowband signal is a pre-set narrowband signal between transmission and reception, and is a signal indicating the execution of UWB communication with coordinated operations. For example, the pilot narrowband signal may be a Sin wave centered at a pre-set frequency as shown in FIG. 4. Also, the pilot narrowband signal may be a plurality of signals with different frequency characteristics. The pilot narrowband signal may be, for example, a plurality of Sin waves with center frequencies of f1, f2, f3 ··· f x respectively.

[0048] In step S15, the narrowband physical layer that operates in coordination with the UWB physical layer may transmit a pilot narrowband signal composed of a plurality of narrowband signals with different pre-set frequencies according to the UWB communication channel. In such a case, for example, by pre-setting in advance that two Sin waves having the frequency characteristics of f1 and f3 correspond to channel B, when the pilot narrowband signal is composed of two Sin waves having the frequency characteristics of f1 and f3, it indicates that the UWB physical layer executes UWB communication using channel B. Thereby, it becomes possible to determine the UWB communication channel in use from the characteristics of the pilot narrowband signal without looking at the content of the UWB communication.

[0049] Also, in step S15, the narrowband physical layer may transmit a pilot narrowband signal composed of a plurality of narrowband signals with different pre-set frequencies according to the time of UWB communication. In such a case, for example, by pre-setting in advance that two Sin waves having the frequency characteristics of f1 and f3 correspond to 3 ms (milliseconds), when the pilot narrowband signal is composed of two Sin waves having the frequency characteristics of f1 and f3, it indicates that the required time for UWB communication of the UWB physical layer is 3 ms. Thereby, it becomes possible to determine the required time for UWB communication from the characteristics of the pilot narrowband signal without looking at the content of the UWB communication. This required time is used to determine the "access stop" period in FIG. 7 described later.

[0050] Next, in step S16, after the UWB physical layer completes the UWB communication, it notifies the upper layer such as the MAC layer of the completion report of the UWB communication.

[0051] By performing the above processing, the operation of the UWB communication ends. According to this embodiment, by introducing the cooperative operation between the UWB physical layer and the narrowband physical layer and associating the transmission of the pilot narrowband signal with the UWB communication of the UWB physical layer, in the determination of the presence or absence of UWB communication, a pilot narrowband signal that is relatively easy to perform CCA such as CSMA / CA, CSMA, or energy detection can be used as a reference signal for substitution. In addition, the mutual interference of UWB signals emitted from different wireless devices can be reduced. Thereby, in an environment where a plurality of systems and devices using UWB communication coexist, collisions and interferences that may occur between UWB data packets transmitted from different systems and devices can be reduced.

[0052] Next, the UWB communication sequences of the plurality of wireless communication terminals 1a, 1b, and 1c will be described. FIG. 5 is a diagram showing a UWB communication sequence when the transmission of the pilot narrowband signal P and the UWB communication T as shown in FIG. 3(a) are started simultaneously.

[0053] First, in step S20, the wireless communication terminal 1a first acquires the transmission right and transmits the pilot narrowband signal P1 and performs UWB communication T1 based on the cooperative operation. In step S20, the wireless communication terminal 1b and the wireless communication terminal 1c attempt channel access, but since they detect the pilot narrowband signal P1 of the wireless communication terminal 1a by CCA, they stop accessing the channel during the UWB communication time t1.

[0054] Next, in step S21, the wireless communication terminal 1b acquires the transmission right and transmits the pilot narrowband signal P2 and performs UWB communication T2 based on the cooperative operation. In step S21, the wireless communication terminal 1c attempts channel access, but since it detects the pilot narrowband signal P2 of the wireless communication terminal 1b by CCA, it stops accessing the channel during the UWB communication time t2.

[0055] Next, in step S22, the wireless communication terminal 1c acquires the transmission right and performs transmission of the pilot narrowband signal P3 based on the cooperative operation and UWB communication T3.

[0056] Through the above-described processing, the UWB communications T1, T2, and T3 of the plurality of wireless communication terminals 1a, 1b, and 1c are completed. Also, the UWB communication times t1, t2, and t3 may be the same or different.

[0057] FIG. 6 is a diagram showing a UWB communication sequence in the case of performing UWB communication T over a predetermined time from the start of transmission of the pilot narrowband signal P as shown in FIG. 3(b).

[0058] First, in step S30, the wireless communication terminal 1a first acquires the transmission right and performs transmission of the pilot narrowband signal P1 based on the cooperative operation and UWB communication T1. In step S30, the wireless communication terminal 1b and the wireless communication terminal 1c attempt channel access, but since they detect the pilot narrowband signal P1 of the wireless communication terminal 1a by CCA, they stop accessing the channel during the UWB communication time t1 after the end of transmission of the pilot narrowband signal P1. In such a case, it is preferable to perform CCA for a time longer than the maximum value of the UWB communication times (t1, t2, t3).

[0059] Next, in step S31, the wireless communication terminal 1b acquires the transmission right and performs transmission of the pilot narrowband signal P2 based on the cooperative operation and UWB communication T2. In step S31, the wireless communication terminal 1c attempts channel access, but since it detects the pilot narrowband signal P2 of the wireless communication terminal 1b by CCA, it stops accessing the channel during the UWB communication time t2 after the end of transmission of the pilot narrowband signal P2.

[0060] Next, in step S32, the wireless communication terminal 1c acquires the transmission right and performs transmission of the pilot narrowband signal P3 based on the cooperative operation and UWB communication T3.

[0061] Through the above-described process, the UWB communications T1, T2, and T3 of the plurality of wireless communication terminals 1a, 1b, and 1c are completed. Also, the UWB communication times t1, t2, and t3 may be the same or different. Further, the transmission of the pilot narrowband signal and the UWB communication may start simultaneously.

[0062] FIG. 7 is a diagram showing a UWB communication sequence in the case of performing UWB communication T after starting the transmission of the pilot narrowband signal P as shown in FIG. 3(c). Also, the arrow Y in FIG. 7 indicates the detection of the pilot narrowband signal.

[0063] First, in step S40, the wireless communication terminal 1a first acquires the transmission right and performs the transmission of the pilot narrowband signal P1 and the UWB communication T1 based on the cooperative operation. In step S40, the wireless communication terminal 1b and the wireless communication terminal 1c attempt channel access, but since they detect the pilot narrowband signal P1 of the wireless communication terminal 1a by CCA, they stop accessing the channel during the UWB communication time t1. In such a case, it is preferable to perform CCA for a time longer than the largest value of the UWB communication times (t1, t2, t3).

[0064] Next, in step S41, the wireless communication terminal 1b acquires the transmission right and performs the transmission of the pilot narrowband signal P2 and the UWB communication T2 based on the cooperative operation. The wireless communication terminal 1c attempts channel access, but since it detects the pilot narrowband signal P2 of the wireless communication terminal 1b by CCA, it stops accessing the channel during the UWB communication time t2.

[0065] Next, in step S42, the wireless communication terminal 1c acquires the transmission right and performs the transmission of the pilot narrowband signal P3 and the UWB communication T3 based on the cooperative operation.

[0066] Through the above-described process, the UWB communications T1, T2, and T3 of the plurality of wireless communication terminals 1a, 1b, and 1c are completed. Also, the UWB communication times t1, t2, and t3 may be the same or different.

Description of Symbols

[0067] 1 Wireless communication terminal 3 Base station 4 Communication line 100 Wireless communication system P Pilot narrowband signal T UWB communication f Frequency t UWB communication time

Claims

1. In a UWB communication system that performs UWB communication based on a UWB physical layer using UWB (Ultra Wide Band) communication, at least one narrowband physical layer that cooperates with the UWB physical layer, and a MAC (Media Access Control) layer that manages the UWB physical layer and the narrowband physical layer, request notification means for notifying a communication request signal for requesting UWB communication from the MAC layer to the narrowband physical layer; determination means for determining an available channel for performing the UWB communication by using any one of energy detection, CSMA (Carrier Sense Multiple Access), or CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) by the narrowband physical layer notified of the communication request signal; report notification means for notifying a clear channel report indicating the result of the determination by the determination means from the narrowband physical layer to the MAC layer based on the determination by the determination means; command notification means for notifying a command signal for performing the UWB communication from the MAC layer to the UWB physical layer and the narrowband physical layer in response to the clear channel report notified by the report notification means; a communication means for transmitting a pilot narrowband signal indicating the execution of the UWB communication using the narrowband physical layer notified of the command signal by the command notification means, and performing the UWB communication using the UWB physical layer notified of the command signal by the command notification means A UWB communication system characterized by the above.

2. The communication means is characterized in that the transmission of the pilot narrowband signal and the UWB communication are started simultaneously. The UWB communication system according to claim 1, characterized in that.

3. The communication means is characterized in that the transmission of the pilot narrowband signal and the UWB communication are terminated simultaneously. The UWB communication system according to claim 2, characterized in that.

4. The communication means is characterized in that the UWB communication is started after the transmission of the pilot narrowband signal is started. The UWB communication system according to claim 1, characterized in that.

5. The communication means is characterized in that the pilot narrowband signal composed of a plurality of narrowband signals having different preset frequencies is transmitted according to the channel for performing the UWB communication. The UWB communication system according to any one of claims 1 to 4, characterized in that.

6. The communication means transmits the pilot narrowband signal composed of a plurality of narrowband signals with different preset frequencies according to the time of the UWB communication. The UWB communication system according to any one of claims 1 to 4, characterized by the above.

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