JP2008151533A - Positioning system and radio communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning system capable of calculating a position of a mobile station if there is at least one base station to be installed without requiring a synchronization system between a mobile station and a base station, or between base stations. <P>SOLUTION: A mobile station 100 which is an object to be positioned by one base station 200 comprises: a standard spreading unit 104 where a signal of the Ultra Wideband (UWB) type generated using a timing signal as a trigger is spread by a standard spreading code (PN0) and set as a standard spreading signal; first and second reception parts 110 and 118 for receiving reflected signals from the base station; a first correlator 114 for detecting a reflected signal from a signal received by the first reception part by correlation with a predetermined spreading code (PN1); a second correlator 118 for detecting a reflected signal from a signal received by the second reception part by correlation with the predetermined spreading code (PN1); and a time difference measuring part 126 for measuring time differences between the timing signal and the reflected signals detected by the first and second correlators. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a side system and a wireless communication device, and is particularly applicable to any system that requires position information in a place where it is difficult to use a GPS (Global Positioning System) such as indoors. As such a system, for example, there is a self-propelled robot used for cleaning, security, delivery and the like. In this specification, a device or the like that is a target of a side position is referred to as a “mobile station” (however, generally referred to as a mobile body), and a device or the like that serves as a reference position for performing a side position of the mobile station. It is referred to as “base station” (however, it is also generally referred to as an individual station or a fixed station).

  Conventionally, when the position of a mobile station is measured using a wireless communication means, the position is measured by a triangulation method using the arrival time difference from each base station. When positioning using a wireless LAN or ultrasonic waves is performed, positioning accuracy of several tens of centimeters is the limit. Therefore, in order to improve the accuracy, Japanese Patent Laid-Open No. 2005-274364 (Patent Document 1) improves the accuracy by mounting a travel meter on a mobile station and comparing it with each other.

  In Japanese Patent Laid-Open No. 2006-220642 (Patent Document 2), the lateral position is performed using ultrasonic waves. This lateral system is a method of detecting the time difference of the time when ultrasonic waves are received by each receiving element of the ultrasonic array sensor, which is an ultrasonic receiving device, the position of each receiving element, and the position of the moving object detected by the direction detecting means. Based on the direction, the direction in which the sound source exists is obtained with respect to the ultrasonic receiving apparatus.

JP 2005-274364 A JP 2006-220642 A

  By the way, when performing position detection by conventional triangulation, as shown in FIGS. 9 and 10, a plurality of existing base stations (three or more stations of A, B, and C) are required. In the side system shown in FIG. 9, the radio waves emitted by the mobile station P are received by three or more base stations A, B, and C whose positions are known in advance. Then, the server calculates the time difference received by each of the base stations A, B, and C, thereby identifying the position of the mobile station P. In the side system shown in FIG. 10, the base stations A, B, and C emit radio waves, the mobile station P receives radio waves, and the mobile station P performs calculations for grasping its own position. is there.

  When such a side system is used for household appliances (cleaning robots, etc.), the load on the installation of the base station increases. This is because a plurality of base stations must be synchronized regardless of whether the mobile station P and the base stations A, B, and C perform position detection. Therefore, in such a side system, it is technically difficult to perform accurate position detection. In addition, since a plurality of base stations must be installed in each room and power supply must be ensured for each base station, there are disadvantages in terms of cost and appearance.

  In addition, the side system using ultrasonic waves has high accuracy at a short distance, but the accuracy at a long distance is very deteriorated. In addition, since a signal is transmitted from the base station, time synchronization between the mobile station and the base station is required to perform accurate measurement.

  Moreover, when considering the use of home appliances, it is assumed that it is used indoors. Therefore, if the most effective GPS (Global Positioning System) is used as a positioning method, an error is generated on the contrary, which is not practical.

  The present invention has been made in view of the above-mentioned problems of conventional side systems, and an object of the present invention is that a mobile station, a base station, and a base station-to-base station synchronization system are unnecessary, and an installed base To provide a new and improved side system and wireless communication apparatus capable of calculating the position of a mobile station if the number of stations is at least one.

  In order to solve the above-described problem, according to a first aspect of the present invention, there is provided a side system including a mobile station to be a side target and a base station for performing the side of the mobile station. . The lateral system of the present invention employs the following configuration (claim 1).

  The mobile station (100) includes a reference spreader (104) that spreads a signal based on an ultra-wideband (UWB) method generated by using a timing signal as a trigger with a reference spreading code (PN0) to form a reference spread signal; A transmitter (108) for transmitting a reference spread signal to the base station, first and second receivers (110, 118) for receiving a reflected signal from the base station (a certain distance apart), and the first A first correlator (114) for detecting the reflected signal based on a correlation with a predetermined spread code (PN1) from a signal received by the receiver, and a predetermined spread code from the signal received by the second receiver A second correlator (118) for detecting the reflected signal by correlation with (PN1), and a time difference measurement for measuring a time difference between the reflected signal detected by the first and second correlators and the timing signal. Part (126) , Comprising a.

  The base station (200) includes a receiving unit (202) that receives a signal from the mobile station, and a reference that detects the reference spread signal based on a correlation between a reference spread code (PN0) from the signal received by the receiving unit. A correlator (206); a spreader (214) that spreads a signal generated by using the reference spread signal as a trigger by a predetermined spread code (PN1) to be a reflected signal; and sends the reflected signal to the mobile station A transmission unit (202) for transmission.

  According to such a side system, the mobile station using the UWB, the base station, and the synchronization system between the base stations are unnecessary, and the position of the mobile station can be accurately calculated. By using the base station as a responder, the absolute position of the mobile station can be calculated by the mobile station itself. If the number of base stations to be installed is at least one, the position of the mobile station can be calculated. Therefore, troublesome wiring at the time of installing the base station and synchronization between the base stations are unnecessary, and it is possible to improve the price reduction and technical ease. In addition, in the UWB system in which communication is performed using short pulses, the accuracy can be set to 1 to 2 cm.

  In the above description, the reference numerals in parentheses attached to the constituent elements are merely examples of corresponding constituent elements in the following embodiments and drawings for the convenience of explanation, and the present invention is not limited thereto. It is not limited to. The same applies to the following.

  The lateral system of the present invention can be applied in various ways, and some application examples are as follows.

  The mobile station may further include a moving direction recognizing unit for recognizing its moving direction (Claim 2). By detecting the moving direction of the mobile station, candidate points for the position of the mobile station can be limited. In addition, by setting the base station position at the wall or the like, the mobile station candidate points can be further narrowed down on the assumption that the mobile station position is indoors, and the mobile station position can be uniquely determined. .

  The mobile station may further include an object distance measuring unit (130a, 130b, 130c, 130d) for measuring a distance to the object in each direction (Claim 3). . By measuring the distance to the object in each direction of the mobile station, the candidate points for the position of the mobile station can be limited. Further, the position of the mobile station can be uniquely determined by combining with the detection of the moving direction.

  The base station (200) includes four receiving units (202) for receiving signals from the mobile station, and a reference spreading code (PN0) corresponding to each receiving unit and received from the signals received by the receiving units. ) And four reference correlators (206) for detecting the reference spread signals based on the correlation with the reference spread signals, and signals generated by using the reference spread signals as triggers corresponding to the respective reference correlators. ~ PN4) four diffusers (214) to be reflected signals, and four transmitters (202) corresponding to each diffuser and transmitting the reflected signals to the mobile station, The four receivers and the four transmitters may have a radiation pattern divided into four quadrants, and the four spreaders may be configured to use different spreading codes. . According to such a configuration, the position of the mobile station is uniquely determined by position measurement using only UWB without detecting the movement direction of the mobile station or measuring the distance to the object in each direction of the mobile station. can do.

  In order to solve the above-described problem, according to a second aspect of the present invention, a radio communication apparatus that is a target of one side by a single base station, and an ultra wideband (UWB) generated using a timing signal as a trigger A reference spreader (104) which spreads a signal according to the system with a reference spread code (PN0) to obtain a reference spread signal, a transmission unit (108) for transmitting the reference spread signal to the base station, and a reflection from the base station The first and second receiving units (110, 118) that receive a signal (a certain distance away) and the reflected signal based on a correlation with a predetermined spreading code (PN1) from the signal received by the first receiving unit A first correlator (114) for detecting the reflected signal, and a second correlator (118) for detecting the reflected signal by correlation with a predetermined spreading code (PN1) from the signal received by the second receiver. , In the first and second correlators Ri time difference measuring unit for measuring a time difference between the detected reflected signal and the timing signal (126), characterized by comprising a radio communication apparatus is provided (claim 5).

  According to such a wireless communication apparatus, a mobile station using UWB, a base station, and a synchronization system between base stations are unnecessary, and the position of the mobile station can be accurately calculated. By using the base station as a responder, the absolute position of the mobile station can be calculated by the mobile station itself. If the number of base stations to be installed is at least one, the position of the mobile station can be calculated. Therefore, troublesome wiring at the time of installing the base station and synchronization between the base stations are unnecessary, and it is possible to improve the price reduction and technical ease.

  The wireless communication apparatus of the present invention can be applied in various ways, and some application examples are as follows.

  Furthermore, it is also possible to have a configuration including a movement direction recognition unit for recognizing its own movement direction (claim 6). By detecting the moving direction of the mobile station, candidate points for the position of the mobile station can be limited. In addition, by setting the base station position at the wall or the like, the mobile station candidate points can be further narrowed down on the assumption that the mobile station position is indoors, and the mobile station position can be uniquely determined. .

  Furthermore, it is also possible to have a configuration including an object distance measuring unit (130a, 130b, 130c, 130d) for measuring the distance to the object in each direction (Claim 7). By measuring the distance to the object in each direction of the mobile station, the candidate points for the position of the mobile station can be limited. Further, the position of the mobile station can be uniquely determined by combining with the detection of the moving direction.

  As described above, according to the present invention, the mobile station, the base station, and the synchronization system between the base stations are unnecessary, and the position of the mobile station can be calculated if at least one base station is installed. It is. Other excellent effects of the present invention will be described in the following description of the best mode for carrying out the invention.

  Exemplary embodiments of a side system and a wireless communication apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
A first embodiment of the present invention will be described.

First, the basic concept of this embodiment will be described.
In the following embodiments, one UWB radio transmitter and two UWB radio receivers are mounted on a mobile station at a predetermined distance. Further, it is a responder type position measuring method in which the mobile station itself measures the position of the mobile station using at least one transceiver as a base station. In the measurement procedure, the base station receives a pulse transmitted from the transmitter of the mobile station, changes the spreading code, and the base station returns a pulse to the two receivers of the mobile station. At this time, the two receivers of the mobile station receive the reply pulse from the base station with a slight time difference. The lateral position is determined by this time difference.

  The synchronization is unnecessary because the clock is completed within the mobile station by a repeater system in which the base station sends back the radio wave emitted by the mobile station. Regarding the delay in sending back, there is an advantage that correction is easy by the simple configuration of UWB.

  Hereinafter, the configuration and operation of the present embodiment will be described in detail. An indoor installation example of this embodiment is shown in FIG. 1, and a block diagram of a mobile station and a base station is shown in FIG.

(1-1) Example of indoor installation of mobile station and base station (Fig. 1)
FIG. 1 is an explanatory diagram showing a state where the mobile station 100 and one base station 200 are installed indoors. In this embodiment, as shown in FIG. 1, one UWB wireless transmitter (represented by reference symbol P) and two UWB wireless receivers (represented by reference symbols A and B) are mounted on a mobile station at a fixed distance. Further, the position of the mobile station is measured by the mobile station itself using at least one transceiver as a base station. The present embodiment is such a responder type position measuring method. In the measurement procedure, the base station receives a pulse transmitted from the transmitter of the mobile station, changes the spreading code, and the base station returns the pulse to the two receivers of the mobile station. At this time, the two receivers of the mobile station receive the reply pulse from the base station with a slight time difference.

The mobile station 100 is an example of the wireless communication device of the present invention, and is a device or the like that is a lateral target in the present system. The mobile station 100 of this embodiment needs to know its own position with high accuracy. A specific example of such a mobile station 100 is a self-propelled robot used for applications such as cleaning, security, and delivery. GPS (Global) is the most common method for determining the position on the ground.
In the Positioning System), it is difficult to perform a high-accuracy indoor position indoors. Therefore, the position is performed using the base station 200 described below.

  The base station 200 is a device or the like for performing the position of the mobile station 100. As shown in FIG. 1, the base station 200 is installed on the ceiling of a room that does not become an obstacle in daily life indoors. Further, for example, by installing the base station 200 in the vicinity of the lighting, it is possible to receive power from the same power source as the lighting.

(1-2) Configuration example of mobile station and base station (FIG. 2)
Configuration examples of the mobile station 100 and the base station 200 will be described with reference to FIG.

(Mobile station 100)
As shown in FIG. 2, the mobile station 100 includes a pulse generator 102, a spreader (PN0) 104, an amplifier 106, an antenna 108 as a transmission function (corresponding to the reference symbol P in FIG. 1), and a reception function (FIG. 1). Of two antennas 110, 118 and two amplifiers 112, 120, two correlators (PN1) 114, 122, two analog-digital converters 116, 124, and a time difference A measurement unit 126 is provided.

  The pulse generator 102 generates a pulse by an ultra-wide band (UWB) system using a timing signal from the time measurement unit 126 as a trigger. The spreader 104 spreads this pulse to the code PN0. Since the signal spread by the spreader 104 is a reference signal in the side of the present embodiment, it is hereinafter referred to as a reference spread signal. The amplifier 106 amplifies the reference spread signal. The antenna 108 transmits the amplified reference spread signal to the base station 200.

  On the other hand, the two antennas 110 and 118 serving as reception functions receive signals (reflected signals) sent back from the base station 200. This reflected signal is a signal generated by the base station 200, and details thereof will be described later. The amplifiers 112 and 120 amplify the reflected signal. Correlators 114 and 122 detect the reflected signal transmitted from base station 200 based on the correlation with the first spreading code PN1 from the received signal. The analog / digital converters 116 and 124 digitally convert the reflected signals.

  The time difference measuring unit 126 measures the time difference between the reflected signals received from the two antennas 110 and 118, and measures the time based on the timing signal, thereby determining the distance from the base station 200 of the two antennas 110 and 118. taking measurement. In the present embodiment, the mobile station 100 is positioned using this measured distance. This point will be further described later with reference to FIG.

(Base station 200)
As shown in FIG. 2, the base station 200 includes an antenna 202 and an amplifier 204 as a reception function, a correlator (PN0) 206, an amplifier 208, an analog / digital converter 210, a pulse generator 212, a spreading code, and the like. It comprises a spreader (PN1) 214 corresponding to PN1, an amplifier 216 as a transmission function, and an antenna 202. In the example illustrated in FIG. 2, the antenna 202 has both a transmission function and a reception function, but a transmission antenna and a reception antenna may be provided separately.

  The antenna 202 receives a signal transmitted from the mobile station 100. The amplifier 204 amplifies the received signal. The correlator 206 detects the reference spread signal transmitted from the mobile station 100 based on the correlation with the correlation value (PN0) from the amplified received signal. The amplifier 208 amplifies the reference spread signal. The analog-digital converter 210 converts the amplified reference spread signal into a digital signal. The pulse generator 212 generates a pulse using this digital signal as a trigger.

  The spreader 214 at the next stage spreads the pulse generated by the pulse generator 212 to the code PN1 to form a spread signal. Since the signal diffused by the diffuser 214 is a signal that is reflected by the mobile station 100 at the side position in this embodiment and used at the side position, it is referred to as a reflected signal in this specification. The amplifier 216 amplifies the reflected signal. The antenna 218 sends the amplified radio wave back to the mobile station 100.

  In the present embodiment, synchronization between the mobile station 100 and the base station 200 is not required, and since only one base station 200 is installed, there is no concept of synchronization between base stations. For this reason, the base station 200 of the present embodiment can have a simple configuration as shown in FIG. 2 and can be easily installed.

  The configuration of the present embodiment is as described above. Next, the operation of this embodiment will be described.

(1-3) Operation of this Embodiment In the mobile station 100, a pulse is generated from the pulse generator 102 triggered by the timing signal, spread to the code PN0 by the spreader 104 at the next stage, amplified by the amplifier 106, and then the antenna 108. More fired.

  In the base station 200, a signal is received by the antenna 202, amplified by the amplifier 204, and then a correlation value is output by the correlator 206 corresponding to the code PN0. This signal becomes a trigger, and the radio wave generated by the pulse generator 212 and spread to the code PN1 by the spreader 214 is sent back to the mobile station 100 from the antenna 218 of the base station 200.

  The signals sent back to the mobile station 100 are detected by the two correlators 114 and 122. The time difference measuring unit 126 measures the time from the timing signal, thereby measuring the distance between the mobile station 100 and the base station 200. This point will be described below.

(1-4) Received signal in mobile station and base station (FIG. 3)
FIG. 3 is an explanatory diagram showing received signals in the mobile station 100 and the base station 200. In FIG. 3, for convenience of explanation, only the period from when the mobile station 100 transmits the reference spread signal to when the mobile station 100 receives the reflected signal is shown.

  As shown in FIG. 3, the pulse width transmitted by the mobile station 100 is Tp, the spatial transmission time between each of the two antennas of the mobile station 100 and the base station 200 is Td, and the response time at the base station 200 is Tl. And If the time difference calculated by the time difference measuring unit 126 is Tt, Tt = 4 × Tp + 2 × Td + Tl. Therefore, the distance X between each of the two antennas of the mobile station 100 and the base station 200 is calculated by X = c (light speed) × Td = c × (Tt−4 × Tp−Tl) / 2.

  In the present embodiment, the lateral position is determined using the time difference at which the two antennas of the mobile station 100 receive the reflected signal. That is, since the mobile station 100 itself transmits the reference spread signal and receives the reflected signal, the distance between the mobile station 100 and the base station 200 can be determined. Further, the absolute position candidate points of the mobile station 100 are narrowed down by using the time difference at which the two antennas of the mobile station 100 receive the reflected signal.

  In the calculation as described above, the position of the mobile station 100 is not uniquely determined. As shown in FIG. 4, when the position detection range is considered with XY coordinates centered on the base station 200, the position is symmetrical in each quadrant. And is limited to four coordinates. In the following description, the upper right quadrant in FIG. 4 is referred to as the first quadrant, the upper left quadrant is referred to as the second quadrant, the lower left quadrant is referred to as the third quadrant, and the lower right quadrant is referred to as the fourth quadrant.

  FIG. 5 is an explanatory diagram showing a positional relationship between the two antennas of the mobile station 100 and the base station 200 when the mobile station 100 exists in the second quadrant. In the following description, as shown in FIG. 5, the distances between the two antennas A and B of the mobile station 100 and the base station 200 are distinguished as Xa and Xb.

  As shown in FIG. 4, the position of the mobile station 100 is not uniquely determined, and four candidate points of the mobile station 100 are given. However, under the assumption that the mobile station 100 moves only indoors and does not exist outside the room, when the base station 200 is installed near a wall, two candidate points out of the four are outdoor. Further, when the base station 200 is installed in a corner of the room, three candidate points out of the four are outdoor. Therefore, by inputting in advance to the mobile station 100 information that the mobile station 100 moves only indoors and does not exist outside the room, the position of the mobile station 100 can be narrowed down or uniquely determined. In this way, the existence of other candidate points does not become a practical problem. Note that another method for narrowing down the candidate points of the mobile station 100 will be further described in an embodiment described later.

  Further, the signals received by the mobile station 100 include a reflected wave reflected by a wall or the like in addition to a signal sent back from the base station 200 without reflection. However, since the UWB (ultra-wideband) method is used in the present embodiment, the signal level of the reflected wave is smaller than that of a signal sent back without reflection. That is, it is possible to determine that the signal level that returns first is the highest and this is a signal that is sent back without reflection. This is also one of the advantages of using UWB in this embodiment.

(Effects of the first embodiment)
As described above, according to the present embodiment, the mobile station 100 using the UWB, the base station 200, and the synchronization system between the base stations are unnecessary, and the position of the mobile station 100 can be accurately calculated. It is. By using the base station 200 as a responder, the absolute position of the mobile station 100 can be calculated by the mobile station 100 itself.

  If the number of base stations to be installed is at least one, the position of the mobile station can be calculated. Therefore, troublesome wiring at the time of installing the base station and synchronization between the base stations are unnecessary, and it is possible to improve the price reduction and technical ease.

(Method for narrowing down candidate points of mobile station 100)
In the method of the first embodiment, as a result of calculating the distances Xa and Xb from the base station 200 to the two antennas, the position detection range is considered in XY coordinates centered on the base station 200 as shown in FIG. In this case, each quadrant is calculated symmetrically and is limited to four coordinates. Therefore, in the following second and third embodiments, several examples will be described for a method of determining which quadrant is located from a limited position.

(Second Embodiment)
A second embodiment of the present invention will be described.
In this embodiment, the mobile station 100 includes a movement direction recognition unit for recognizing the movement direction of the mobile station 100.

  In general, a self-propelled mobile station needs to be equipped with an azimuth recognition device in order to maintain movement direction recognition and straightness. This device can be easily realized with a gyro or GPS. By using such a device as the movement direction recognition unit of the present invention, the mobile station itself can recognize the movement direction of the mobile station. Since such an apparatus needs only to recognize the moving direction, it does not require a mechanism such as changing the spreading code or considering the influence of reflected waves. For this reason, an advanced measuring device is not necessary, and it is possible to use, for example, GPS indoors (excluding underground) in addition to the gyro.

  As described above, since the mobile station is provided with the movement direction recognition unit for recognizing its own movement direction, the traveling direction of the mobile station is limited. In the example shown in FIG. 4, assuming that the receiving unit A is on the left side and the receiving unit B is on the right side with respect to the traveling direction of the mobile station 100 as indicated by the arrows in the figure, the mobile station 100 If the mobile station 100 is traveling upward (in the positive direction of the Y axis), it can be determined that the position of the mobile station 100 is in either the second or third quadrant. Further, if the mobile station 100 is traveling downward on the page (the negative direction of the Y axis), the position of the mobile station 100 can be determined to be in either the first or fourth quadrant. Thus, by limiting the traveling direction of the mobile station 100, the position of the mobile station 100 calculated by the UWB communication in the first embodiment can be limited to ½.

(Effect of 2nd Embodiment)
As described above, according to the present embodiment, by detecting the moving direction of the mobile station 100 by a simple means such as a gyro, the position of the mobile station 100 is halved compared to the first embodiment. It can be limited to. Furthermore, by installing the base station 200 at a position where the X axis of FIG. 4 is near the wall, candidate points in the third and fourth quadrants (or the first and second quadrants) can be excluded, The position of the mobile station 100 can be uniquely determined.

(Third embodiment)
A third embodiment of the present invention will be described.
In the present embodiment, as shown in FIG. 6, the mobile station 100 includes an object distance measurement function for measuring a distance to an object (such as a wall) in each direction. In the example illustrated in FIG. 6, measurement units 130 a, 130 b, 130 c, and 130 d are provided in four directions as the object distance measurement unit.

  Usually, a self-propelled mobile station is equipped with a plurality of sensors in order to maintain the recognition of the moving direction and straightness. In addition, because home appliance mobile stations are required to move indoors while avoiding furniture and walls installed indoors, they can use shock sensors, ultrasonic sensors, etc. to recognize walls and furniture, avoid operations, etc. It is carried out. One of them is to install an ultrasonic distance measuring device as a wall-to-wall sensor. This distance measurement method has an advantage that the accuracy can be increased at a short distance, but the same or higher accuracy can be achieved even when UWB is used.

  Also, since UWB is used for communication with the base station 200, as shown in FIG. 7, the radiation pattern of the transmitter installed at the top of the mobile station 100 is made hemispherical so that Can be received by a receiver (measurement unit 130b in the example of FIG. 7) mounted on the side surface of the mobile station 100, and the distance to the wall surface can be measured. In this case, unlike communication with the base station 200, it is not necessary to make a determination using a spreading code, and reception is possible with a simple configuration based on power detection. In other words, the receiver used for the opposite wall does not use a spread code, but only needs to receive the first reflected pulse, so that it can be a receiver having a simple detection function.

  Thus, by limiting the distance to the wall surface of the mobile station 100, the position calculated in the UWB communication of the first embodiment can be limited to ½. That is, if the distance from the object distance measuring units 130a and 130b to the object is larger than the distance from the other object distance measuring units 130c and 130d to the object, the position of the mobile station 100 is shown in FIG. If the distance from the object distance measuring unit 130c, 130d to the object is larger than the distance from the other object distance measuring unit 130a, 130b to the object, The position of the mobile station 100 can be determined to be one of the first and third quadrants shown in FIG.

(Effect of the third embodiment)
As described above, according to the present embodiment, by detecting the distance to the wall of the mobile station 100, the position of the mobile station 100 can be limited to ½ compared with the first embodiment.

  Furthermore, by combining with the second embodiment (detecting the moving direction), the position of the mobile station 100 can be uniquely determined. That is, in the second embodiment, candidate points can be narrowed down to the position of the mobile station 100 in either the first or fourth quadrant, or in the second or third quadrant. In the third embodiment, candidate points can be narrowed down to the position of the mobile station 100 in either the second or fourth quadrant, or the first or third quadrant. In this way, by calculating the combined distance from the radio base station, the traveling direction of the mobile station, and the distance from the wall, it is measured in which quadrant of the XY coordinates in FIG. 4 where the mobile station exists. And the position of the mobile station 100 can be uniquely determined.

(Fourth embodiment)
A fourth embodiment of the present invention will be described.
In the present embodiment, unlike the second and third embodiments, a method for narrowing down candidate points for the position of the mobile station 100 only by position measurement by UWB will be described. When performing position measurement only by UWB, as shown in FIG. 8, transceivers 200-1, 200-2, 200-3, and 200-4 having a radiation pattern divided into four quadrants are provided in the base station 200. The quadrant in which the mobile station is located is determined by installing and giving each transmitter / receiver a different spreading code. After that, an accurate position can be calculated by measuring the response time from the base station with two receivers mounted on the mobile station.

  The configuration of each of the transceivers 200-1, 200-2, 200-3, 200-4 includes an antenna 202, an amplifier 204, a correlator (PN0) 206, an amplifier 208, an analog / digital converter 210, and a pulse shown in FIG. The configuration of the generator 212, the diffuser 214, and the amplifier 216 is substantially the same. However, the spreading codes used in the spreader 214 are different from each other in each of the transceivers 200-1, 200-2, 200-3, 200-4 (for example, spreading codes PN1, PN2, PN3, PN4). Thereby, the mobile station 100 can determine which one of the transceivers 200-1, 200-2, 200-3, and 200-4 is a reflected signal.

(Effect of the fourth embodiment)
As described above, according to the present embodiment, the quadrant in which the mobile station 100 exists can be specified, and the position of the mobile station 100 can be uniquely determined. Further, according to the configuration of the present embodiment, since the base station 200 can be installed at an arbitrary position, for example, by installing the base station 200 in the vicinity of the illumination, power can be supplied from the same power source as the illumination. Is possible.

  Although the preferred embodiments of the side system and the wireless communication apparatus according to the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, in the above-described embodiment, the configuration in which the mobile station 100 includes the two reception units A and B has been described. However, the present invention is not limited to this, and the configuration may include three or more reception units. . By increasing the number of receiving units, the accuracy of the lateral position can be further improved.

  The present invention can be used for a side system and a wireless communication device, and in particular, can be applied to any system that requires position information in a place where it is difficult to use GPS such as indoors. As such a system, for example, there is a self-propelled robot used for cleaning, security, delivery and the like.

It is explanatory drawing which shows the indoor installation example of a mobile station and a base station. It is explanatory drawing which shows the structural example of the mobile station concerning 1st Embodiment, and a base station. It is explanatory drawing which shows the received signal of the mobile station in 1st Embodiment. It is explanatory drawing which shows the side system concerning 2nd Embodiment. It is explanatory drawing which shows the side system concerning 2nd Embodiment. It is explanatory drawing which shows the side system concerning 3rd Embodiment. It is explanatory drawing which shows the side system concerning 3rd Embodiment. It is explanatory drawing which shows the side system concerning 4th Embodiment. It is explanatory drawing which shows an example of the conventional side system. It is explanatory drawing which shows an example of the conventional side system.

Explanation of symbols

100 Mobile station 102 Pulse generator 104 Spreader (PN0)
106 amplifier 108 antenna 110 antenna 112 amplifier 114 correlator (PN1)
116 Analog-to-digital converter 118 Antenna 120 Amplifier 122 Correlator (PN1)
124 Analog-to-digital converter 126 Time difference measurement unit 130a, 130b, 130c, 130d Moving direction recognition unit 200 Base station 202 Antenna 204 Amplifier 206 Correlator (PN0)
208 Amplifier 210 Analog to Digital Converter 212 Pulse Generator 214 Spreader (PN1)
216 amplifier

Claims (7)

In a side system including a mobile station to be a side target and a base station for performing the side of the mobile station,
The mobile station
A reference spreader that spreads a signal by an ultra-wideband method generated by using a timing signal as a trigger with a reference spreading code to form a reference spread signal;
A transmitter for transmitting the reference spread signal to the base station;
First and second receiving units for receiving reflected signals from the base station;
A first correlator for detecting the reflected signal by correlation with a predetermined spreading code from the signal received by the first receiver;
A second correlator for detecting the reflected signal by correlation with a predetermined spreading code from the signal received by the second receiver;
A time difference measuring unit for measuring a time difference between the reflected signal detected by the first and second correlators and the timing signal;
With
The base station
A receiver for receiving a signal from the mobile station;
A reference correlator for detecting the reference spread signal by correlation with a reference spread code from the signal received by the receiving unit;
A spreader that diffuses a signal generated using the reference spread signal as a trigger with a predetermined spreading code to form a reflected signal;
A transmitter for transmitting the reflected signal to the mobile station;
A lateral system characterized by comprising:   The side system according to claim 1, wherein the mobile station further includes a movement direction recognition unit for recognizing a movement direction of the mobile station.   The side system according to claim 1, wherein the mobile station further includes an object distance measuring unit for measuring a distance to the object in each direction. The base station
Four receivers for receiving signals from the mobile station;
Four reference correlators corresponding to each of the receiving units and detecting the reference spread signal by correlation with a reference spread code from a signal received by each of the receiving units;
Corresponding to each of the reference correlators, four spreaders that diffuse a signal generated by using the reference spread signal as a trigger with a predetermined spreading code to obtain a reflected signal;
Corresponding to each of the spreaders, four transmitters for transmitting the reflected signal to the mobile station;
With
The four receiving units and the four transmitting units have a radiation pattern divided into four quadrants,
The side system according to claim 1, wherein the four spreaders use different spreading codes. A wireless communication device targeted by a base station,
A reference spreader that spreads a signal by an ultra-wideband method generated by using a timing signal as a trigger with a reference spreading code to form a reference spread signal;
A transmitter for transmitting the reference spread signal to the base station;
First and second receiving units for receiving reflected signals from the base station;
A first correlator for detecting the reflected signal by correlation with a predetermined spreading code from the signal received by the first receiver;
A second correlator for detecting the reflected signal by correlation with a predetermined spreading code from the signal received by the second receiver;
A time difference measuring unit for measuring a time difference between the reflected signal detected by the first and second correlators and the timing signal;
A wireless communication apparatus comprising:   The wireless communication apparatus according to claim 1, further comprising a movement direction recognition unit for recognizing its own movement direction.   The wireless communication apparatus according to claim 5, further comprising an object distance measuring unit for measuring a distance to the object in each direction.

Images