JP2006352810A - Radio control chip set with positioning function, radio communication card with positioning function, radio terminal, and position measuring network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio control chip set with a positioning function which is excellent in temporal responsiveness and the secrecy of communication with low power consumption not to impose a load on a host computer so as to highly precisely measure a position, and to provide a radio communication card with a positioning function, a radio terminal, and a position measuring network system. <P>SOLUTION: The radio control chip set 1a with a positioning function includes: an MAC control part 71 having a position measurement control means 75a, which takes out the transmission source MAC addresses of whole reception packets so as to define the addresses as the elements of an RSSI table by correspondence to reception signal strength; and a storage control part 74 for storing the elements in the RSSI table in a memory section 8. The radio control chip set 1a with the positioning function is included in the radio communication card with the positioning function, the radio terminal, and the position measuring network system. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless control chip set with a positioning function that wirelessly communicates and measures a received signal strength indicator (RSSI) in the surroundings and outputs the signal to a host computer, and a wireless communication card with a positioning function including the same Furthermore, a radio terminal capable of measuring the position in the radio network by mounting the radio control chip set with a positioning function, and the position of the radio terminal can be measured using communication in the radio network The present invention relates to a position measurement network system.

  In recent years, research on position measurement has been actively conducted. In particular, GPS has come to occupy the main position for practical position measurement with the spread of car navigation. However, because GPS requires communication with satellites, it is basically only available outdoors, such as public indoor spaces such as stations, airports, museums, and libraries, or commercial indoor spaces such as department stores and event venues. It can be said that it is incapable of providing location information in Japan. As a position measurement technique other than GPS, E-OTD (Enhanced Observed Time Differences), which receives time from a plurality of base stations using a mobile phone, and performs position measurement by performing triangulation by time lag, reverse In addition, a technique such as TDOA (Time Difference of Arrival) in which radio waves from a mobile phone are received by a plurality of base stations and a position is measured from the time difference has been put into practical use (see, for example, Patent Document 1). However, E-OTD and TDOA need to synchronize time with a plurality of base stations with high accuracy, and dedicated hardware or the like is required for each base station. And when measuring an indoor position, as will be described later, the measurement accuracy is lowered due to a wall, a roof, and the like.

  Therefore, a system using a wireless LAN using ultrasonic waves, infrared rays, or radio waves of 2.4 GHz band, 5 GHz band, or the like has been studied to measure the indoor position. Of these, systems using ultrasonic waves and infrared rays are expensive to introduce such facilities because the installation location of receivers is limited due to the characteristics of these media and special equipment is required. The maintenance cost after installation also tends to increase. Therefore, even if a system using ultrasonic waves or infrared rays is suitable in a special environment, it is not expected to spread in general. In this regard, wireless communication is performed between devices equipped with a wireless LAN that performs wireless communication using a protocol that conforms to a standard such as IEEE 802.11b / a / g, or a wireless device such as Bluetooth, homeRF, or UWB (Ultra Wideband). In addition to being able to perform wireless communication and position measurement with a single device, a position measurement network system that measures the position of equipment can be installed relatively inexpensively because it uses a wireless device that has already been widely used. Is.

  By the way, as one of the position measurement network systems using a wireless LAN, the relationship between the RSSI of radio waves emitted from a wireless terminal at a base station constituting the wireless LAN and the position is learned in advance, and the base station performs wireless positioning at the time of position measurement. There is known a RADAR system that measures the RSSI of a radio wave and measures the position of a wireless terminal. However, in this system, the relationship between the RSSI of the radio terminal and the position of the radio terminal must be set in a table (map) in advance, and calibration must be performed to increase the measurement accuracy. This is because radio waves are attenuated, reflected, diffracted, and the like in indoor wireless communication. However, calibration is a monotonous and troublesome operation, and the following technique has been proposed to reduce this (see Patent Document 2).

  The technique of Patent Document 2 records an RSSI for each room of a building, and uses a regression function that generates sufficiently accurate position information according to RSSI even if there is a lack of calibration data or the minimum available data. Suggest to use. The regression algorithm takes a set of RSSIs from a known location in the building and generates a function that maps the RSSI to the (x, y) location, which estimates the new location (s). Used for. Isomorphic basis functions such as Gaussian kernel functions are used for regression.

  As described above, in the RADAR system or the like, it is necessary to learn the relationship between the RSSI and the position at the base station for each wireless terminal, and calibration is necessary to improve accuracy. The technique of Patent Document 2 can reduce the calibration, but is basically the same as the RADAR system, and a minimum calibration is necessary.

  What should be noted in the conventional position measurement network system is that the positional relationship between the base station and the wireless terminal is important in order to obtain the location information of the wireless terminal, and this is only a problem, and the positional relationship between the wireless terminals is a problem. That was never done. Therefore, even if there are many wireless terminals, they have not been useful for position measurement.

  Therefore, three of the inventors of the present invention receive a packet sent from a surrounding host by a base station or a wireless terminal (hereinafter referred to as a host) in the wireless LAN, and measure RSSI at that time. Proposed a position measurement network system, WiPS (Wireless LAN based Indoor Positioning System) for estimating (hereinafter, measuring) the distance between hosts (see Non-Patent Document 1). The received packet is not only a packet addressed to itself but also all packets transmitted and received between surrounding hosts.

  This system has the duality that all hosts measure RSSI as well as RSSI, and unlike the conventional position measurement network system, calibration is not necessary. Since each host has a function of measuring each other's RSSI, the accuracy is not improved by calibration, but the viewpoint centered on the reference station is changed to the viewpoint centering on the wireless terminal, and the distance between the hosts based on the RSSI The accuracy is improved by increasing the number of data to be collected.

FIG. 15 is an overall view of a conventional position measurement network system. In FIG. 15, G _{1 to} G ₃ are reference stations that have positioning means such as GPS and own their own position information, and M _{1 to} M ₅ are wireless terminals that are movable and do not own their own position information. is there. Each of the wireless terminals M _{1 to} M ₅ and the reference stations G _{1 to} G ₃ can be collectively expressed as a host h _i (0 ≦ i <8) that constitutes a wireless LAN. At this time, the wireless terminals M _{1 to} M ₅ are h _i (0 ≦ i <5), and the reference stations G _{1 to} G ₃ are h _i (5 ≦ i <8). Each host h _i has a function of measuring RSSI of a host h _j (i ≠ j) capable of direct communication and a function of estimating (measuring) a distance. Further, one of the reference stations G _{1 to} G ₃ and the wireless terminals M _{1 to} M ₅ , for example, the reference station G ₁ , aggregates the distances with other hosts h _j estimated by the respective hosts h _i and performs position measurement. Functions as a positioning server to perform. In the system shown in FIG. 15, the wireless LAN including the reference stations G _{1 to} G ₃ and the wireless terminals M _{1 to} M ₅ constitutes an ad hoc network.

By way of example, since the wireless terminal M ₁ can only communicate with only the reference station G ₁ as a reference station, it has only been known that the wireless terminal M ₁ exists within the communication area of the reference station G ₁ . However, in the position measurement network system using WiPS, the distance is measured by measuring the RSSI of a total of four hosts using communication with the wireless terminals M ₂ , M ₃ , and M ₄ in addition to the reference station G _1. Can do. The estimated distance between the hosts is transmitted from the wireless terminal M ₁ to the positioning server (here, the reference station G ₁ ), and the positioning server combines these to perform position measurement.

Therefore, the calculation performed by the conventional WiPS position measurement network system will be briefly described. The number of wireless terminals is m, the total of the reference station and wireless terminals is n, and the host h _i (its position is represented by a vector p _i ) and the host h _j (its position is represented by a vector p _j ) communicate directly. When the measurement distance d _ij when possible and the distance when both cannot communicate directly with each other are d _{max +} , the position measurement of the wireless terminal is performed between the position list of the reference station {vector p _i | m ≦ i <n} and the host. In other words, it is a problem of obtaining the position list {vector p _i | 0 ≦ i <m} of the wireless terminal by using the list {d _ij | 0 ≦ i, j <n; i ≠ j} of the measured distances. Note that d _{max +} = max (| vector p _i -vector p _j |, d _max ) is defined where d _max is the maximum distance that radio waves can reach.

However, | vector p _i −vector p _j | ˜d _ij , and the measurement distance d _ij calculated by measuring RSSI includes an error. Accordingly, if all of these are calculated as true distances, contradiction occurs as a whole. Therefore, this relationship is satisfied as much as possible, and a position as a harmonic point that does not cause contradiction is determined.

The positioning algorithm executed by the positioning server can be the least square method, but is based on the steepest descent method. At this time, the initial value of the calculation of the position of the wireless terminal (host h _i | 0 ≦ i <m) is the position of the center of gravity of the base station (host h _i | m ≦ i <n) that can directly communicate with this wireless terminal. Assuming that On the premise of this initial value and measurement distance d _ij , a correction amount vector Δ _i for the position is obtained at each wireless terminal, and the correction amount vector Δ _i is added to each vector p _i to form a new vector p _i. This correction is repeated based on the position, and the process ends when the maximum value of the correction amount vector Δ _i falls below a predetermined threshold.

This correction amount vector Δ _i takes the difference between the measurement distance d _ij calculated by measuring RSSI or the above d _{max +} and the distance l _ij, and a parameter α for convergence (empirically 0.1 to 0). Is a value multiplied by .05). Through this iterative calculation, the position of the wireless terminal can be determined as an optimal solution that satisfies the measurement distance _dij obtained by measuring the RSSI as much as possible while keeping the position information of the reference station obtained separately.

JP 2005-110314 A JP 2004-325440 A IPSJ Journal “Computing System”, vol. SIG10 (ACS2), July 2003, Teruaki Kitasuka, Tsuneo Nakanishi, Satoshi Fukuda, p. 131-p. 140

  As described above, the conventional WiPS position measurement network system does not need to be synchronized like TDOA, and is expensive because it is a dedicated facility like a system using ultrasonic waves or infrared rays. There is no. Further, although calibration is inevitable with the RADAR system and the technique of Patent Document 2, it is an excellent position measurement network system in that this is unnecessary.

  However, in the conventional position measurement network system based on WiPS, all the packets transmitted and received by surrounding hosts are received, the RSSI is measured, and this is transmitted to the host computer together with the received packets to calculate the distance. Although the computer only needs RSSI, the computer has to receive and process a packet not addressed to itself. Since the processing is performed using the promiscuous mode, the secrecy of communication becomes a problem when spreading. Moreover, it is necessary to send the result to the positioning server after performing the calculation, and these processes are burdensome for the host computer. In addition, the processing capability of the host computer is unnecessarily reduced due to unnecessary processing, and the time responsiveness is also deteriorated. Further, in the case of a mobile terminal, low power consumption is particularly desired. However, such wasteful processing increases power consumption, and position measurement using the mobile terminal becomes practically difficult.

  Therefore, in order to solve such problems, the present invention is a wireless control with a positioning function that can perform position measurement with high accuracy, low power consumption, good time responsiveness, excellent communication confidentiality without imposing a load on the computer. An object is to provide a chip set, a wireless communication card with a positioning function, a wireless terminal, and a position measurement network system.

  The present invention includes a baseband unit provided with a modulation unit and a demodulation unit, a lower layer control unit provided with a MAC control unit that has a physical layer interface and performs communication control of a MAC layer, a rewritable memory unit, These are wireless control chip sets with a positioning function provided on a single board, and the MAC control unit extracts the source MAC addresses of all received packets and associates them with the received signal strength. Position measurement control means serving as an element of the RSSI table is provided, and the storage control unit stores the element in the RSSI table of the memory unit.

  According to the wireless control chip set with a positioning function of the present invention, since processing of received packets and generation of the RSSI table are performed by the wireless control chip set, it is not necessary to put a load on the host computer, and low power consumption can be achieved. Time response is good. Also, since it does not operate in promiscuous mode, the confidentiality of communication is not compromised.

  According to the wireless communication card with a positioning function of the present invention, it is possible to process packets to be transmitted and received just by attaching them, and to generate an RSSI table. In addition, since no processing is performed by the host computer, time response is improved. Since it does not operate in promiscuous mode, it can be a wireless communication card with a positioning function having excellent communication confidentiality.

  According to the wireless terminal of the present invention, the position can be measured using a positioning server, the RSSI table is generated, the power consumption is low, the time response until obtaining the measurement result is good, and the operation is performed in the normal mode. Therefore, the confidentiality of communication is excellent.

  According to the position measurement network system of the present invention, since the wireless terminal generates the RSSI table and the positioning server calculates, the time response until obtaining the measurement result is good, and the wireless terminal operates in the normal mode. It is possible to provide a position measurement network system with excellent secrecy.

  The first embodiment of the present invention is a rewrite of a baseband unit provided with a modulation unit and a demodulation unit, a lower layer control unit provided with a MAC control unit that has a physical layer interface and performs MAC layer communication control. This is a wireless control chip set with a positioning function provided on a single board, and the MAC control unit extracts and receives the source MAC addresses of all received packets. Position measurement control means is provided that is associated with the signal strength and serves as an element of the RSSI table, and the storage control unit is a wireless control chip set with a positioning function in which the element is stored in the RSSI table of the memory unit. Since the received packet processing and the RSSI table are generated, it is not necessary to put a load on the host computer and low power consumption can be achieved. In addition, since no processing is performed by the host computer, time response is improved.

  The second mode of the present invention is a mode dependent on the first mode, and is an RSSI measurement unit that measures received signal strength, and RSSI data that transmits data measured by the RSSI measurement unit to a lower layer control unit. Is a wireless control chip set with a positioning function provided on the board, and it is possible to effectively use the received signal strength that has not been used so far and generate an RSSI table with only one wireless control chip set. it can.

  The third mode of the present invention is a mode subordinate to the first mode or the second mode, in which the position measurement control means extracts the source MAC address and associates this with the received signal strength and is an element of the RSSI table. In the wireless control chipset with a positioning function, the first process is performed, and the second process in which the MAC control unit discards the received packet that is not the MAC address addressed to the received packet after the first process is performed. Yes, all packets that can be wirelessly communicated can be received, but since the MAC control unit can be set to the normal mode instead of the promiscuous mode, the confidentiality of communication is not reduced.

  A fourth aspect of the present invention is a form dependent on any one of the first to third aspects, wherein an orthogonal modulation / demodulation unit is provided connected to a baseband unit, and the baseband unit and lower layer control unit And a wireless control chip set with a positioning function integrally formed with the memory unit, and the wireless communication card can be made more compact.

  A fifth aspect of the present invention includes the radio control chip set with a positioning function according to any one of the first to third aspects, a transmission / reception unit that performs frequency conversion and amplification of a reception signal and a transmission signal, and an antenna. It is a wireless communication card with a positioning function, which processes a packet to be transmitted / received simply by mounting it, and generates an RSSI table, so that it is not necessary for the host computer to process it, thereby reducing power consumption. In addition, since no processing is performed by the host computer, time response is improved. Since it does not operate in promiscuous mode, the confidentiality of communication is not reduced.

  According to a sixth aspect of the present invention, there is provided a radio control chip set with a positioning function according to any one of the first to third aspects, a transmission / reception unit that performs frequency conversion and amplification of a reception signal and a transmission signal, an antenna, and network communication And a wireless terminal that requests a position measurement from a positioning server that performs a position measurement calculation and transmits an RSSI table. The wireless terminal can perform position measurement using the positioning server and generates an RSSI table. It is possible to provide a wireless terminal that has excellent power responsiveness to obtaining a measurement result and excellent communication confidentiality because it operates in the normal mode.

  The seventh aspect of the present invention generates an RSSI table by associating a positioning server that performs position measurement calculation, a transmission source MAC address of a packet received by radio waves, and a received signal strength, and performs position measurement on the positioning server. A wireless terminal that requests and transmits the RSSI table, and a plurality of reference terminals that can wirelessly communicate with the wireless terminal and can provide positioning means to notify the positioning server of its own location information. A position measurement network system is a position measurement network system that performs calculation of position measurement of a wireless terminal based on an RSSI table, position information, and a radio terminal's maximum radio wave reach, and the wireless terminal generates an RSSI table Since the positioning server performs calculations for position measurement, the time response until obtaining the measurement result is good, and the wireless terminal To operate in Marumodo, it is possible to provide an excellent position measurement network system communication secrecy.

  A wireless control chipset with a positioning function, a wireless communication card with a positioning function, a wireless terminal, and a position measurement network system according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a wireless terminal equipped with a positioning function wireless communication card in Embodiment 1 of the present invention, FIG. 2 is a block diagram of a positioning control-equipped wireless control chip set in Embodiment 1 of the present invention, and FIG. FIG. 4 is a block diagram of the main part of a wireless terminal in the first embodiment of the present invention, and FIG. 5 is a block diagram of the main part of the positioning server in the first embodiment of the present invention. FIG. 6A is an explanatory diagram of an RSSI table provided in the radio control chip set with a positioning function according to the first embodiment of the present invention, and FIG. 6B is an explanatory diagram of position information notification notified from the reference station. FIG. 7 is an explanatory diagram of the all-host RSSI table according to the first embodiment of the present invention, and FIG. 8 is an explanatory diagram of the position table according to the first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a wireless communication card with a positioning function such as an IEEE802.11b / a / g or a superheterodyne method that performs wireless communication using protocols such as IEEE 802.11b / a / g, Bluetooth, homeRF, UWB (Ultra Wideband), 1a is a baseband unit, a MAC (Medium Access Control) control unit, a memory unit, etc. of the positioning function wireless communication card 1 that are integrally provided on the substrate, and performs wireless communication control and at the same time uses RSSI measurement values. This is a radio control chip set with a positioning function that creates an RSSI table and transmits / receives the RSSI table to / from a host computer. The wireless control chip set 1a with a positioning function is a module in which each functional unit is formed as a module, and can also be referred to as a wireless control board module with a positioning function.

  Reference numeral 2 is an antenna, 3 is a host computer that can perform wireless communication by mounting a wireless communication card 1 with a positioning function, and 4 is a reception signal and a transmission signal provided between the antenna 2 and the wireless control chip set 1a with a positioning function. An RF / IF converter (transmission / reception unit of the present invention) that performs frequency conversion and amplification of the signal, 5 is a quadrature demodulation from the received signal to the I / Q signal, and conversely, an orthogonal modulation from the I / Q signal to the transmitted signal is performed. This is an I / Q modulation / demodulation unit (orthogonal modulation / demodulation unit of the present invention) to be performed. When the RF / IF conversion unit 4 and the I / Q modulation / demodulation unit 5 are combined into a single RF control unit for an analog circuit, the RF control unit, the radio control chipset with positioning function 1a, the antenna 2, etc. Thus, the positioning function-equipped wireless communication card 1 is configured.

  Next, the radio control chip set 1a with a positioning function will be described with reference to FIG. 2. Reference numeral 6 denotes a base for modulating a digital I / Q signal and outputting it to the I / Q modulator / demodulator 5 and demodulating an analog I / Q signal. It is a band part. Note that a function of performing processing such as spread spectrum processing and inverse despreading processing may be added to the modulation unit 65 and the demodulation unit 62 (described later) of the baseband unit 6. 7 is a lower layer control unit for controlling the physical layer and the MAC layer, 8 is a memory section (memory unit of the present invention) composed of a rewritable memory such as a flash memory, 8a is a rewritable memory provided in the memory section 8, Reference numeral 8b denotes an RSSI table portion provided in the rewritable memory 8a. An RSSI table is stored in the RSSI table portion 8b. In the first embodiment, the digital circuit chip set including the lower layer control unit 7, the baseband unit 6, and the memory section 8 is the radio control chip set 1a with a positioning function, but an RSSI measurement unit is provided. A chip set including a digital circuit and an analog circuit including the I / Q modulation / demodulation unit 5 and possibly the RF / IF conversion unit 4, for example, a radio control chip set 1b with a positioning function shown in FIG. .

  Next, configurations of the wireless control chipset with a positioning function and the wireless communication card with a positioning function according to the first embodiment will be described in detail with reference to FIG. In the RF / IF converter 4, reference numeral 41 denotes an antenna sharing unit that is switched at the time of transmission / reception, 42 is a signal setting superimposing unit that sets and supplies a local frequency signal or carrier signal, and 42 a is a temperature for the signal setting superimposing unit 42. Compensation crystal oscillator, 43 is an RF amplifier such as LNA on the reception side, 44 and 44a are band-pass filters (abbreviated as BPF) on the reception side of the RF / IF converter 4, and 45 is a signal superimposed by the signal setting superimposing unit 42 A receiving side frequency converting unit, 46 is a transmitting side power amplifier (abbreviated as PA), 47 and 47a are band pass filters (abbreviated as BPF) of the RF / IF converting unit 4, and 48 is a signal setting superimposing unit It is a frequency converter on the transmission side that superimposes a signal.

  Next, the I / Q modulation / demodulation unit 5 will be described. 51 is a phase shift unit in which the phase difference of the carrier wave signal is set and controlled by the signal setting superimposing unit 42, 52 is an AGC (Automatic Gain Control) amplifier on the receiving side of the I / Q modulation / demodulation unit 5, 53 is an I / Q demodulation unit, Reference numeral 54 denotes a low-pass filter (abbreviated as LPF) provided for each of the I / Q signals. An RSSI measuring unit 55 detects RSSI from the magnitude of the AM voltage of the AGC amplifier 52. Although the RSSI measurement unit 55 is formed on the substrate side of the RF / IF conversion unit 4 in the first embodiment, it is not always necessary, and can be provided on the substrate side on which the baseband unit 6 is formed. In the RSSI measurement unit 55, when RSSI is measured in the unit dBm and xdBm, for example, x = -12.2 dBm is measured, [x] + 100 = 88 (where [x] is an integer) is calculated, -12.2 dBm is converted into a converted RSSI value “88” of 1 byte for position measurement. Data from the RSSI measurement unit 55 is input to the baseband unit 6, further sent to the lower layer control unit 7, and written in an RSSI table described later together with the MAC address as an element of the RSSI table. Next, reference numeral 56 denotes an amplifier on the transmission side of the I / Q modulation / demodulation unit 5.

Next, details of the wireless control chip set with a positioning function of the first embodiment will be described with reference to FIG. First, the baseband unit 6 will be described. 55a is an RSSI data line for sending data measured by the RSSI measuring unit 55 to the lower layer control unit 7, 61 is an I / O for transferring data, and 62 is a receiving side. The demodulator 63 demodulates the analog data into digital data, and 63 denotes an AD converter that converts an analog I signal into a digital I signal (in FIG. 2, I
63a is an AD converter (abbreviated as Q ADC in FIG. 2) for converting an analog Q signal into a digital Q signal. The RSSI data line 55a is connected to the I / O 61, and the data of the converted RSSI value is sent to the lower layer control unit 7 for each packet. Reference numeral 64 denotes an AGC unit for controlling the magnitude of the signal on the receiving side, and controls the AGC amplifier 52 of the I / Q modulation / demodulation unit 5.

Reference numeral 65 denotes a modulation unit that modulates analog data on the transmission side into digital data, and 66 denotes a DA converter that converts a digital I signal into an analog I signal (in FIG. 2, I
66a is a DA converter (abbreviated as QDAC in FIG. 2) for converting a digital Q signal into an analog Q signal. Reference numeral 67 denotes an APL unit that controls the power amplifier 46.

  Subsequently, the lower layer control unit 7 will be described. 71 is a MAC control unit that can control the MAC layer in a normal mode that discards received packets that are not its own MAC address, and is provided with a position measurement control means 75 for performing preprocessing to extract a source MAC address, which will be described later , 72 is a PHY I / F (physical layer interface of the present invention) that performs physical layer communication processing. 73 is an I / F between the lower layer control unit 7 and the host computer 3, 74 is a storage control unit for reading and writing data, and 74 a is in a chip storing a control program for configuring the lower layer control unit 7. ROMs 74 b are on-chip RAMs of the lower layer control unit 7. The storage control unit 74 writes the source MAC address and the converted RSSI value determined by the position measurement control unit 75 as elements of the RSSI table to the RSSI table, and performs reading.

  Next, reference numeral 75 denotes a position measurement control unit provided in the MAC control unit 71, which extracts a transmission source MAC address from all received packets and associates the converted RSSI value with an element of the RSSI table. A program for this purpose is provided in the on-chip ROM 74a, and the position measurement control means 75 is configured as a function realizing means. Further, the position measurement control means 75 can transmit a RSSI table in response to a request from the host computer 3. 75a is an average value calculation means for calculating the converted RSSI value or the average value of RSSI, 75b is a counter for counting time or the number of packets, and 76 is a WEP engine that performs encryption processing using a WEP key.

  As shown in FIG. 6A, the position measurement control means 75 associates all transmission source MAC addresses with converted RSSI values (or RSSIs) as elements of the RSSI table, and the storage control unit uses these elements. Are stored in the RSSI table, but the MAC control unit 71 performs control to discard the received packet that is not the MAC address addressed to the received packet after this processing. Therefore, the MAC control unit 71 can collect the MAC addresses of all the surrounding wireless terminals while being in the normal mode that allows only the user to pass, and can associate this with the RSSI to perform calibration. Instead, the accuracy of position measurement can be increased by increasing the amount of data collected.

  As described above, since the position measurement control means 75 is provided, it is possible to reduce the processing amount of the host computer 3, and it is possible to execute processing under normal mode, which can be executed only in the promiscuous mode. Confidentiality is not reduced.

  Note that the MAC address in FIG. 6A or the like is 48 bits composed of the manufacturer's ID, for example, “AA: BB: CC” and the product-specific ID “11:22:01”. Two IDs are unique values that do not exist. The extracted MAC address is stored in the RSSI table described later together with the converted RSSI value as corresponding to the wireless terminal.

  Subsequently, the memory section 8 will be described. As shown in FIG. 6A, the RSSI table of the RSSI table unit 8b includes a MAC address of the transmission source, and accordingly a host name of the transmission source depending on the case, and a converted RSSI value of 1 byte corresponding to this MAC address, As will be described, the average value is stored as an element. Alternatively, instead of the converted RSSI value as described above, the RSSI in dBm units can be directly stored, although the number of bits is increased. The RSSI table is updated every time a packet is received.

  By the way, there are a plurality of packets transmitted from one host, for example, per second, and the converted RSSI values in the RSSI table are stored in such a form that they are added in time series in the order received within this time. The MAC control unit 71 is provided with a counter 75b. The counter 75b counts the time or the number of packets. When the predetermined time elapses or the predetermined number of packets is reached, the average value calculating means 75a converts the converted RSSI. The average value (or RSSI) is calculated. Thereby, even if there is a temporary radio wave interference, the noise can be leveled. When the RSSI table is requested from the host computer 3 periodically, for example, at intervals of 1 second, the position measurement control means 75 transmits the RSSI table. The RSSI table transmitted to the host computer 3 may be composed of all the above-mentioned elements, but is preferably composed of the MAC address and the converted RSSI value (or RSSI) as an average value, which is sufficient. This RSSI table is also effective to notify the host computer 3 of the variance value and the number of packets together with the average value.

  As described above, the host computer 3 according to the first embodiment performs the process of generating the RSSI table using the positioning function-equipped wireless control chip set or the positioning function-equipped wireless communication card, and the RSSI table is used for the positioning function-equipped wireless control chip set. Since it is stored in the memory unit and the distance calculation is performed by the positioning server 9, it is not necessary to perform all processing in the host computer 3, the processing capacity of the host computer 3 is reduced, power is wasted, There is nothing to do. Further, since the processing is performed by the wireless control chipset with positioning function or the wireless communication card with positioning function, and further the calculation is performed by the positioning server 9, the time response is improved. The wireless terminal according to the present invention includes not only a host computer that is used with a wireless communication card with a positioning function mounted, but also a built-in computer with a built-in wireless control chipset with a positioning function and an antenna 2.

Next, the position measurement network system according to the first embodiment of the present invention will be described. In FIG. 3, 9 is a positioning server, 101 to 105 are movable wireless terminals, 106, 107 and 108 are reference stations, and 106a, 107a and 108a are positioning means mounted on the reference stations 106, 107 and 108. As in the description of the prior art, “M” is attached to the wireless terminal and “G” is attached to the reference station. The positioning means 106a, 107a, and 108a are, for example, a GPS that directly measures a position, a laser distance measuring instrument that measures a distance from a reference point, and the like. In the first embodiment, the east longitude direction and the north latitude direction are the x direction and the y direction from the point of accuracy, and the distance from the predetermined reference point p ₀ is measured. The reference stations 106 to 108 may be fixed terminals or mobile terminals. In the first embodiment, the reference stations 106 to 108 are fixed terminals constituting the Ethernet (registered trademark) and the like including the positioning server 9. Reference numeral 108 denotes an access point for the wireless terminals 101 to 105. Of course, a network operating in the ad hoc mode may be used instead of the network operating in the infrastructure mode.

Now, as shown in FIG. 8, the positions p ₆ , p ₇ , and p ₈ of the reference stations 106, 107, and 108 are p ₆ (152, 123), where the reference point p ₀ is the origin (0, 0) and the unit is m. ), P ₇ (125, 110), p ₈ (135, 150). In order to facilitate the following description, both the wireless terminal 101 through 105 and the reference station 106, 107, 108 treated collectively as a host _{h i,} respectively host _h 1 to h ₅ of the wireless terminal 101 to 105 base station the 106 to 108 to the host _h 6 _{~h 8.}

First, the configuration of the main parts of the wireless terminals 101 to 105 (hosts h _{1 to} h ₅ ) constituting the position measurement network system will be described. The calculation control unit of the host computer 3 is a CPU as hardware, reads out each control program from the memory unit, and executes each control function as software as a function realizing unit.

  In FIG. 4, 31 is a slot into which the positioning function wireless communication card 1 is inserted, 32 is provided in the calculation control unit, and is periodically, for example, every second with respect to the position measurement control means 75 of the positioning function wireless communication card 1. The positioning client control means requests the RSSI table to the positioning server 9 and requests the positioning server 9 to measure the position periodically, for example, every second. The positioning client control means 32 is the function realizing means described above. Reference numeral 33 denotes a timing unit that measures the timing when an RSSI table request or a position measurement request is made.

  Reference numeral 34 denotes request packet generation means for generating a packet for transferring the RSSI table to the positioning server 9 and requesting position measurement. Note that the request packet generation means 34 of the reference station equipped with the positioning means notifies the positioning server 9 of its own position information by the position information notification as shown in FIG.

  Next, reference numeral 35 denotes network communication control means for transmitting the packet generated by the request packet generation means 34 to the network using a protocol such as UDP or TCP / IP, and 36 is a wired network I / F. When the positioning server 9 is wirelessly linked to the host computer 3 via the positioning function wireless communication card 1, the request packet is transmitted from the I / F 73 of the positioning function wireless communication card 1, but the positioning server 9 3 is connected via a 100Base-TX cable or the like as shown in FIG. 3, the request packet is transmitted to the positioning server 9 via the wired network I / F 36.

  When the position measurement (position calculation) is completed in the positioning server 9 and the position table of the measurement result is transmitted to the host computer 3, 37 is a storage control unit for storing it, and 38 is a memory unit of the host computer 3. , 38a are position table units provided in the memory unit 38, and 38b is an RSSI table unit for storing RSSI tables. Note that the position table shown in FIG. 8 is in the initialization stage before calculation.

  In this way, the host computer 3 main body of the first embodiment does not perform packet processing for RSSI measurement during operation, and also performs position measurement by calculation on the measurement server. Therefore, the host computer 3 main body performs the position table, RSSI. It is only storing and updating the table, and the processing capability is not lowered by a series of position measurement processes, and power is not wasted.

  Next, the configuration of the main part of the positioning server 9 in the position measurement network system according to the first embodiment will be described. The calculation control unit of the positioning server 9 is also a CPU as hardware, and reads each control program from the memory unit and executes each control function as software as a function realization means.

In the position measurement network system according to the first embodiment, the number of wireless terminals is m, the total number of reference stations and wireless terminals is n, and hosts h _i and h _j can directly communicate with each other, as described in the description of the prior art. Distance d _ij , and the distance when direct communication is not possible is d _{max +} . At this time, the position measurement of the position measurement network system according to the present invention is performed by measuring the position of the reference station {vector p _i | m ≦ i <n} and the measurement distance {d _ij | 0 ≦ i, j <n; i ≠ j}. Is used to find the position {vector p _i | 0 ≦ i <m} of the wireless terminal. However, there is a very high possibility that there is an error in the RSSI and the measurement distance obtained by measuring this, and this is harmonized so that no contradiction occurs between hosts, and the position of the wireless terminal is determined. .

In FIG. 5, reference numeral 91 indicates whether the position of the position table shown in FIG. 8 is an unmeasured or uncalculated position (f _i = 0 representing “false” is assigned in FIG. 8), or an obtained actually obtained position is Initialization determination means for determining whether or not the initial value is actualized (specified) depending on whether it has been calculated or has been calculated (f _i = 1 representing “true” in FIG. 8); Reference numeral 92 denotes position calculation means. As shown in FIG. 8, a value such as (0, 0) is mechanically assigned to a case where f _i = 0 where no specific initial value is specified. If the initialization determining unit 91 determines that there is a case where f _i = 0, the position calculating unit 92 calculates an initial value for this host h _{i according} to (Equation 1). _Li in (Equation 1) is defined by (Equation 2). Note that | L _i | is the number of elements of L _i . When all the hosts h _i are determined to have f _i = 1 and no ones have f _i = 0, the calculation of the initial value of the position ends.

この（数１）の意味は、初期値を基準局の重心の位置にする、ということであり、これを図３で説明すると、ホストｈ_２（Ｍ_２）は５つのホスト、ｈ_１（Ｍ_１）、ｈ_３（Ｍ_３）、ｈ_５（Ｍ_５）、ｈ_６（Ｇ_１）、ｈ_７（Ｇ_２）と直接通信可能（ｄ_ｍａｘより距離が短い）であるが、ｈ_６，ｈ_７はｆ_６，ｆ_７＝１であり、ｈ_１，ｈ_３，ｈ_５はいずれもｆ_１，ｆ_３，ｆ_５＝０である。このとき、Ｌ_ｉ＝｛６，７｝であり、｜Ｌ_ｉ｜＝２であるから、ベクトルｐ_２＝（ベクトルｐ_６＋ベクトルｐ_７）／２となる。従って、ホストｈ_２（Ｍ_２）の位置ｐ_２の初期値は基準局Ｇ_１，Ｇ_２の重心の位置になる。なお、ホストｈ_１（Ｍ_１）は基準局としては基準局Ｇ_１としか通信可能でないため、ｈ_６（Ｇ_１）の位置が初期値となる。あまり意味はないが、１個の場合も重心といえる。

The meaning of (Equation 1) is that the initial value is set to the position of the center of gravity of the reference station. This will be described with reference to FIG. 3. Host h ₂ (M ₂ ) is five hosts, h ₁ (M ₁ ), H ₃ (M ₃ ), h ₅ (M ₅ ), h ₆ (G ₁ ), h ₇ (G ₂ ) can be directly communicated (distance is shorter than d _max ), but h ₆ , h ₇ Is f ₆ , f ₇ = 1, and h ₁ , h ₃ , and h ₅ are all f ₁ , f ₃ , and f ₅ = 0. At this time, since L _i = {6,7} and | L _i | = 2, vector p ₂ = (vector p ₆ + vector p ₇ ) / 2. Accordingly, the initial value of the position p ₂ of the host h ₂ (M ₂ ) is the position of the center of gravity of the reference stations G ₁ and G ₂ . Since the host h ₁ (M ₁ ) can only communicate with the reference station G ₁ as a reference station, the position of h ₆ (G ₁ ) is the initial value. Although it does not make much sense, it can be said that the center of gravity is one.

Subsequently, the positioning server 9 calculates distances l _ij and d _{max +} between the positions p _i and p _j . Reference _numeral 93 denotes first distance calculation means for calculating the distance l _ij , and 94 denotes second distance calculation means for calculating the distance d _{max +} . Here, l _ij is expressed by ( _Expression 3), and d _{max +} is expressed by (Expression 4). Note that d _max is the maximum distance that radio waves can reach, and when radio waves do not reach, the actual distance between the positions p _i and p _j is d _{max +} .

９５はこの距離ｌ_ｉｊとベクトルｐ_ｉ，ｐ_ｊから（数５）によって単位長ベクトルｕ_ｉｊを求める単位長ベクトル演算手段である。

Reference _numeral 95 denotes a unit length vector computing means for obtaining a unit length vector u _ij from the distance l _ij and the vectors p _i and p _j by (Equation 5).

また、９６は、送信されたＲＳＳＩテーブルのＲＳＳＩ、あるいは換算ＲＳＳＩ値から計算したＲＳＳＩに基づいて、位置ｐ_ｉ，ｐ_ｊ間の距離ｄ_ｉｊを（数６）によって計算するＲＳＳＩ−距離演算手段である。ＲＳＳＩ−距離演算手段９６は各ホストからＲＳＳＩテーブルを受信すると、図７に示す全ホストＲＳＳＩテーブルを作成してその後の距離ｄ_ｉｊの演算に供する。図７は本発明の実施例１における全ホストＲＳＳＩテーブルの説明図である。

Reference numeral 96 denotes an RSSI-distance calculation means for calculating the distance d _ij between the positions p _i and p _j based on the RSSI calculated from the RSSI of the transmitted RSSI table or the converted RSSI value by (Equation 6). is there. When the RSSI-distance calculation means 96 receives the RSSI table from each host, the RSSI-distance calculation means 96 creates an all-host RSSI table shown in FIG. 7 and uses it for the subsequent calculation of the distance _dij . FIG. 7 is an explanatory diagram of the all-host RSSI table according to the first embodiment of this invention.

  Note that (Equation 6) is premised on attenuation based on free space loss. FIG. 9 is an explanatory diagram showing the relationship between RSSI and distance in Example 1 of the present invention. In addition, it can replace with (Equation 6) and the calculation by the model which considered the influence of the wall of a building and the reflection of the ground can also be performed.

ここに、Ｒは単位がｄＢｍのＲＳＳＩであり、Ｒ_０は距離が０のときの値で実験的に求められるもので、例えば３１．０ｄＢｍ程度のものである。また、λ＝ｃ／ｆで、ｃ＝３×１０^８ｃｍ／ｓ、ｆ＝２．４ＧＨｚ等の周波数である。

Here, R is RSSI having a unit of dBm, and R ₀ is obtained experimentally with a value when the distance is 0, for example, about 31.0 dBm. Further, λ = c / f, c = 3 × 10 ⁸ cm / s, f = 2.4 GHz, and the like.

Reference numeral 97 denotes a correction amount calculation means for calculating the correction amount vector Δ _i in (Expression 7) for the wireless terminal of the host h _i (0 ≦ i <m). By the steepest descent method. Here, L is expressed by (Equation 8) and K is expressed by (Equation 9). α is a parameter for accelerating convergence and has a value of about 0.1 to 0.05.

この（数７）の修正量ベクトルΔ_ｉの意味を説明すると、位置ｐ_ｊから電波が届く位置ｐ_ｉのホストの場合（圏内ホストの集合Ｌ）は、（数６）で計算した距離ｄ_ｉｊと位置テーブルの位置ｐ_ｉ，ｐ_ｊ間の距離ｌ_ｉｊとの差が修正量であり、圏外の場合（圏外ホストの集合Ｋ）は、位置ｐ_ｊから電波の届く最大距離ｄ_ｍａｘよりも計算上距離ｌ_ｉｊが小さいときのみこの差が修正量となり、そのほかはこの部分の修正量は０ということである。

The meaning of the correction amount vector Δ _i in (Equation 7) will be described. In the case of the host at the position p _i where the radio wave arrives from the position p _j (the set L of the in-range hosts), the distance d _ij calculated in (Equation 6). And the distance l _ij between the positions p _i and p _{j of the} position table is a correction amount, and in the case of out-of-service (set K of out-of-service hosts) is calculated from the maximum distance d _{max that the} radio wave can reach from the position p _j This difference is the correction amount only when the upper distance l _ij is small, and the other correction amount is 0.

That is, in the case of FIG. 3, since the host h ₆ (G ₁ ) can communicate with _three hosts, h ₁ (M ₁ ), h ₂ (M ₂ ), and h ₃ (M ₃ ) (from d _max (The distance is short), and the difference between the distance d _ij and the distance l _ij multiplied by α is the first correction amount, and h ₄ (M ₄ ), h ₅ (M ₅ ), h ₇ (G ₇ ), Since h ₈ (G ₈ ) is out of the service area, this difference is multiplied by α to obtain the second correction amount only when the radio wave arrival distance d _max is larger than the distance l _ij .

With the correction by the first and second sums, it is possible to gradually approach the harmony point from the initial value. Incidentally, the positioning system of Example 1, which position _{p i} of a large number of hosts _{h i (m ≦ i <n} ) is fixed, will correct the position _{p i} of the host _{h i (0 ≦ i <m} ) Therefore, even when multipath fading occurs due to radio wave reflection, diffraction, etc., multiple paths are affected and tend to have relatively good measurement results compared to conventional RADAR systems. is there.

Subsequently, in FIG. 5, 98 is an updating means for updating the value of the position p _{i in} the position table when the correction amount Δ _i is calculated and updated by (Equation 10), and 99 is whether or not the calculation result has converged. It is a convergence determination means for determining. This convergence is determined by whether or not the correction amount Δ _i falls within the predetermined threshold γ, and the position measurement ends when it falls within the threshold γ.

そこで、本発明の実施例1の測位システムで行われる処理をフローチャートに基づいて説明する。まず、測位機能付無線通信カードで実行される処理を図１０に基づいて説明する。図１０は本発明の実施例１における測位機能付無線通信カードで実行される処理のフローチャートである。図１０に示すように、周囲のホストが送信したパケットを受信するまで待機する（ｓｔｅｐ１）。パケットを受信した場合、ＲＳＳＩを測定し（ｓｔｅｐ２）、ＭＡＣアドレスを取り出し（ｓｔｅｐ３）、これらを要素としてＲＳＳＩテーブルを更新する（ｓｔｅｐ４）。

Therefore, processing performed in the positioning system according to the first embodiment of the present invention will be described based on a flowchart. First, processing executed by the positioning function-equipped wireless communication card will be described with reference to FIG. FIG. 10 is a flowchart of processing executed by the wireless communication card with a positioning function according to the first embodiment of the present invention. As shown in FIG. 10, the process waits until it receives a packet transmitted by a surrounding host (step 1). When the packet is received, the RSSI is measured (step 2), the MAC address is extracted (step 3), and the RSSI table is updated using these as elements (step 4).

  Here, it is determined whether or not it is a predetermined timing (predetermined time interval). If it is not the predetermined timing, the process returns to step 1, and if it is the predetermined timing, an average value of RSSI is calculated (step 6). Next, it is checked whether or not there is an RSSI table request from the host computer (step 7). If there is no request, the process returns to step 1 and waits. If there is a request, the RSSI table consisting of necessary elements is transferred to the host computer. (Step 8).

  Next, processing executed by the host computer will be described with reference to FIG. FIG. 11 is a flowchart of processing executed by the host computer according to the first embodiment of the present invention. In FIG. 11, the process waits until the position measurement request mode is entered (step 11). If this mode is entered, immediately, or if the request mode is continued, whether a predetermined time, for example, 1 second has elapsed since the previous position measurement. Is checked (step 12), and if the predetermined time has elapsed, the RSSI table is requested of the positioning function wireless communication card (step 13).

  When the RSSI table is received, the positioning server is requested to measure the position and the RSSI table is transmitted, and the reference station notifies the positioning server of the position information (step 14). After that, it waits until the position measurement result is transmitted from the positioning server (step 15), and when the position measurement result is obtained, the position table data is updated (step 16). After the update, the process returns to step 11 and waits for a predetermined time.

  Finally, processing executed by the positioning server will be described with reference to FIG. FIG. 12 is a flowchart of processing executed by the positioning server in Embodiment 1 of the present invention. As shown in FIG. 11, the positioning server waits until there is a request for position measurement from each host (step 21). If there is a request, it is determined whether the location of each host is materialized (step 22). If it is not materialized (initialized), initialization is repeated to give an initial value for the location (step 22). step23).

When the position is embodied, the correction amount vector Δ using the distance d _ij calculated by (Equation 6) using RSSI, the distance l _ij calculated by (Equation 3) using the specified position, and the like. _i is calculated (step 24). Subsequently, it is determined whether or not the maximum absolute value of the correction amount vector Δ _i has converged within a predetermined threshold γ (step 25). If the absolute value is larger than the predetermined threshold γ, the vector p _i is Update with the vector p _i + Δ _i (step 26), and if it converges within the threshold γ, the position table is updated (step 27). After that, based on this position table, the position measurement result is notified to each host that has requested the position measurement (step 28), and the process returns to step 21 and waits until there is a position measurement request from each host.

  As described above, the positioning system, the wireless control chipset with a positioning function, and the wireless communication card with a positioning function according to the first embodiment of the present invention have been described. The experimental results of the position measurement using the positioning system will be described. FIG. 13 is an experimental result diagram of the positioning system in Example 1 of the present invention outdoors, and FIG. 14 is an experimental result diagram of the positioning system in Example 1 of the present invention indoors.

  In the experiment of the outdoor positioning system shown in FIG. 13, two PDAs are placed at a height of 110 cm on the concrete surface, and the distance between the PDAs is 1 m, 2 m, 3 m, 4 m, 6 m, 8 m, and 10 m. It was measured for seven cases. In FIG. 13, WiPS is an experimental value of the positioning system of Example 1, and RSSI is an experimental value calculated by RSSI. There are 3 experimental values for the positioning system of Example 1 and 6 experimental values for RSSI. According to the experiment of the outdoor positioning system shown in FIG. 13, it can be seen that the experimental value of the positioning system of Example 1 has a smaller variation than that measured by RSSI.

  Next, the indoor positioning system experiment shown in FIG. 14 is an experiment in which seven PDAs are arranged at regular intervals at intervals of 25 cm on a desk having a height of 70 cm, and the PDAs at both ends are used as reference stations with a distance of 1.5 m. It is. Of the points plotted in FIG. 14, the value of 1.5 m is the position (here, distance) of the PDA of the reference station and is not an experimental value. According to the experimental result of FIG. 14, it can be seen that the measured value of the positioning system of Example 1 is very close to the actually measured distance. Indoors are more accurate than outdoors, and the smaller the distance, the higher the accuracy.

  As described above, the positioning system according to the first embodiment of the present invention shows a better measurement result as the distance is shorter, and it can be seen that the position measurement device becomes more effective when there are many wireless terminals indoors. In addition, the wireless control chipset with a positioning function and the wireless communication card with a positioning function according to the first embodiment of the present invention can perform high-accuracy position measurement without applying a load to the host computer side with low power consumption. Since packet processing is performed by the control chip set or the wireless communication card with a positioning function, the time response of the position measurement is improved, and the confidentiality of communication is not deteriorated.

  The present invention relates to a wireless control chip set with a positioning function that wirelessly communicates and measures RSSI and outputs it to a host computer for position measurement, a wireless communication card with a positioning function, and a wireless equipped with this wireless control chip set with a positioning function The present invention can be applied to a position measurement network system including a terminal and this wireless terminal.

1 is a configuration diagram of a wireless terminal equipped with a wireless communication card with a positioning function in Embodiment 1 of the present invention. 1 is a configuration diagram of a wireless control chip set with a positioning function in Embodiment 1 of the present invention. 1 is an overall configuration diagram of a position measurement network system according to a first embodiment of the present invention. Block diagram of essential parts of a wireless terminal in Embodiment 1 of the present invention Block diagram of the main part of the positioning server in Embodiment 1 of the present invention (A) Explanatory drawing of RSSI table provided in radio control chip set with positioning function in embodiment 1 of the present invention, (b) Explanatory drawing of position information notification notified from reference station Explanatory drawing of all the host RSSI tables in Example 1 of this invention Explanatory drawing of the position table in Example 1 of this invention. Explanatory drawing which shows the relationship between RSSI and distance in Example 1 of this invention. The flowchart of the process performed with the radio | wireless communication card with a positioning function in Example 1 of this invention The flowchart of the process performed by the host computer in Example 1 of this invention The flowchart of the process performed with the positioning server in Example 1 of this invention. FIG. 4 is a diagram showing the results of an outdoor experiment of the positioning system in Example 1 of the present invention. Indoor experiment result diagram of the positioning system in Example 1 of the present invention Overall view of a conventional position measurement network system

Explanation of symbols

1 wireless communication card with positioning function 1a, 1b wireless control chip set with positioning function 2 antenna 3 host computer 4 RF / IF conversion unit 5 I / Q modulation / demodulation unit 6 baseband unit 7 lower layer control unit 8 memory section 8a rewritable memory 8b RSSI table section 9 Positioning server 31 Slot 32 Positioning client control means 33 Timekeeping section 34 Request packet generation means 35 Network communication control means 36 Wired network I / F
37 Storage Control Unit 38 Memory Unit 38a Position Table Unit 38b RSSI Table Unit 41 Antenna Sharing Unit 42 Signal Setting Superposition Unit 42a Temperature Compensation Crystal Oscillator 43 RF Amplifier 44, 44a Band Pass Filter 45 Frequency Conversion Unit 46 Power Amplifier 47, 47a Band Pass Filter 48 Frequency conversion unit 51 Phase shift unit 52 AGC amplifier 53 I / Q demodulation unit 54 Low pass filter 55 RSSI measurement unit 55a RSSI data line 56 Amplifier 61 I / O
62 Demodulator 63, 63a AD converter 64 AGC unit 65 Modulator 66, 66a DA converter 67 APL unit 71 MAC controller 72 PHY I / F
73 I / F
74 Storage controller 74a On-chip ROM
74b On-chip RAM
75 Position measurement control means 75a Average value calculation means 75b Counter 76 WEP engine 91 Initialization determination means 92 Position calculation means 93 First distance calculation means 94 Second distance calculation means 95 Unit length vector calculation means 96 RSSI-Distance calculation means 97 Correction Quantity calculation means 98 Update means 99 Convergence determination means 101-105 Wireless terminals 106, 107, 108 Reference stations 106a, 107a, 108a Positioning means

Claims (7)

A baseband unit provided with a modulation unit and a demodulation unit, a lower layer control unit provided with a MAC control unit having a physical layer interface and performing communication control of the MAC layer, and a rewritable memory unit, Is a wireless control chip set with a positioning function provided on a single board, and the MAC control unit extracts the source MAC addresses of all received packets and associates them with the received signal strengths in the RSSI table. A wireless control chip set with a positioning function, characterized in that a position measurement control means serving as an element is provided, and a storage control section stores the element in the RSSI table of the memory section. The RSSI measurement unit for measuring the received signal strength and an RSSI data line for transmitting data measured by the RSSI measurement unit to the lower layer control unit are provided on the substrate. Wireless control chip set with positioning function. The position measurement control unit extracts a source MAC address and performs a first process that associates the MAC address with a received signal strength and uses it as an element of an RSSI table. For the received packet after the first process, The wireless control chip set with a positioning function according to claim 1 or 2, wherein the MAC control unit performs a second process of discarding a received packet that is not a MAC address addressed to itself. The orthogonal modulation / demodulation unit is provided in connection with the baseband unit, and is configured integrally with the baseband unit, the lower layer control unit, and the memory unit. Wireless control chip set with positioning function. A radio communication card with a positioning function, comprising: the radio control chip set with a positioning function according to any one of claims 1 to 3, a transmission / reception unit for performing frequency conversion and amplification of a reception signal and a transmission signal, and an antenna. . A wireless control chip set with a positioning function according to any one of claims 1 to 4, a transmission / reception unit that performs frequency conversion and amplification of a reception signal and a transmission signal, an antenna, and network communication control means, A wireless terminal that requests a positioning server to perform position measurement and transmits the RSSI table. A positioning server that performs calculation of position measurement, a source MAC address of a packet received by radio waves, and a received signal strength are associated with each other to generate an RSSI table, request the position measurement to the positioning server, and transmit the RSSI table A position measurement network system comprising a wireless terminal that performs wireless communication with the wireless terminal, and a plurality of reference terminals that are equipped with positioning means and that can notify the positioning server of their position information. Then, the positioning server performs a position measurement calculation of the wireless terminal based on the RSSI table, the position information, and the maximum radio wave reachable distance of the wireless terminal.

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