JP5138574B2 - COMMUNICATION SYSTEM, COMMUNICATION DEVICE, AND COMMUNICATION CONTROL METHOD - Google Patents

Abstract

The invention provides a communication system, a communication apparatus and a communication control method, wherein, a wireless base station (1) receives a plurality of a plurality of a plurality of signals transmitted from wireless terminals (2A-2D), the wireless base station (1) measures received delay times of a plurality of signals, and under the condition that the measured delay time exceeds the preset admissible time, the wireless base station can transmit the delay notices representing the delays generated in the signal to one of a wireless terminal as a transmitting source of the delayed signals and a wireless terminal as a transmitting source for transmitting the signals by the next slot time of the slot utilized during transmitting by the delayed signals. One of the wireless terminals (2A-2D) for receiving the delay notices can enable the transmitting speed of the signal transmitted by the time slot to be increased, thereby preventing the deterioration of the communication quality of the signal received in the communication apparatus.

Description

  The present invention includes a first communication device and a plurality of second communication devices, and signals are transmitted between the first communication device and the plurality of second communication devices using a plurality of time slots obtained by dividing a communication time zone. The present invention relates to a communication system that performs transmission, a communication device in the communication system, and a communication control method in the communication system.

  In a wireless communication system that performs time division duplex (TDD) and time division multiplexing (TDMA) communication between a plurality of wireless terminals and a wireless base station, the distance between each wireless terminal and the wireless base station is different for each wireless terminal. Different. For this reason, even though different time slots are assigned to the respective radio terminals, the radio base station may simultaneously receive burst signals from the respective radio terminals due to a propagation delay caused by a difference in distance. is there.

In order to prevent such simultaneous reception (collision) of burst signals, for example, in the techniques described in Patent Literature 1 and Patent Literature 2, a radio base station transmits a control signal for preventing collision to each radio terminal. . Each wireless terminal forcibly adjusts the transmission timing of the burst signal based on the received control signal. Such control is referred to as time alignment control.
JP 2001-169343 A JP 2002-77087 A

  However, when the wireless terminal moves from the vicinity to the distance with respect to the wireless base station, the time position (reception window) of the burst signal received by the wireless base station becomes the time even if the time alignment control as described above is performed. It may come off to the rear of the slot.

  As described above, when there is a burst signal in which the reception timing in the radio base station is extremely delayed, signal collision occurs, and normal demodulation becomes difficult. That is, communication quality deteriorates.

  In particular, since the PHS (Personal Handy Phone System) wireless communication system is premised on base station layout design (cell planning) in a micro cell, a change in the distance between the wireless terminal and the wireless base station is caused by the macro cell. When it becomes larger, the above-mentioned signal collision tends to occur.

  In view of the above problems, an object of the present invention is to provide a communication system, a communication apparatus, and a communication control method that prevent deterioration in communication quality of a signal received in the communication apparatus.

In order to solve the above-described problems, the present invention has the following features. First, the first aspect of the present invention includes a first communication device (wireless base station 1) and a plurality of second communication devices (wireless terminals 2A to 2D), and a plurality of time slots obtained by dividing a communication time zone. And a communication system (wireless communication system 10) that transmits signals between the first communication device and the plurality of second communication devices, wherein the first communication device includes the plurality of second communication devices. A signal reception unit (signal reception processing unit 152) that receives a signal transmitted by the apparatus using the time slot, and a delay time measurement unit (delay time) that measures a delay time of the signal received by the signal reception unit When the delay time measured by the measurement unit 154) and the delay time measurement unit exceeds an allowable time, which is a maximum delay time within which the time position of the signal falls within the time slot of the time slot, signal A delay notification indicating a delay is a time used for transmission of the second communication device that is a transmission source of the signal whose delay time exceeds the allowable time, and a signal whose delay time exceeds the allowable time Measured by a delay notification transmission unit (delay notification transmission processing unit 162) that transmits to one of the second communication devices that is a transmission source of a signal transmitted using a time slot next to the slot, and the delay time measurement unit A frequency bandwidth extension unit (frequency band extension unit 158) for extending a frequency bandwidth used for signal transmission when the delayed time exceeds the allowable time, and the second communication device includes: A delay notification receiving unit (delay notification reception processing unit 252) that receives the delay notification from the first communication device; and the delay notification is received by the delay notification receiving unit. With the transmission rate increasing portion that increases the transmission rate of the signal to be transmitted using a slot and a (transmission rate increase portion 256), the delay notification transmission section, a frequency bandwidth after expansion by the frequency bandwidth extending unit and gist that you send the delay notification including.

In such a communication system, the first communication device causes the delay time of the signal from the second communication device to exceed the allowable time, which is the maximum delay time in which the time position of the signal falls within the time slot time zone. In this case, considering that there is a high possibility that the communication quality of the signal is deteriorated, transmission is performed using the second communication device that is the transmission source of the signal, and the time slot that is next to the time slot used for transmission of the signal. The delay notification is transmitted to the second communication device that is the transmission source of the signal to be transmitted. On the other hand, when the second communication device receives the delay notification, the second communication device increases the transmission rate of the signal to be transmitted using the time slot. By increasing the signal transmission speed, the signal transmission time is shortened. As a result, collision of signals can be prevented, and further, deterioration of communication quality can be prevented. Furthermore, in such a communication system, when the delay time exceeds the allowable time, the first communication device expands the frequency bandwidth used for signal transmission, and sets the frequency bandwidth after the expansion to the first frequency bandwidth. By notifying the two communication devices, the second communication device can expand the frequency bandwidth used for signal transmission and increase the transmission rate.

According to a second aspect of the present invention, there is provided a communication device (wireless base station) that transmits a signal to a plurality of other communication devices (wireless terminals 2A to 2D) using a plurality of time slots obtained by dividing a communication time zone. 1) a signal receiving unit (signal reception processing unit 152) that receives a signal transmitted by the plurality of other communication devices using the time slot, and a signal received by the signal receiving unit. A delay time measuring unit (delay time measuring unit 154) for measuring a delay time, and the delay time measured by the delay time measuring unit is a maximum time in which the time position of the signal falls within the time slot of the time slot. When a certain allowable time is exceeded, a delay notification indicating a signal delay is sent to the other communication device that is a transmission source of the signal whose delay time exceeds the allowable time, and the delay time is the allowable time Time A delay notification transmission unit (delay notification transmission processing unit) that transmits to any one of the other communication devices that are transmission sources of signals transmitted using a time slot next to a time slot used for transmission of a signal exceeding 162), wherein when the delay time measured by the delay time measuring unit exceeds the allowable time, and a frequency bandwidth extension unit for extending the frequency bandwidth used for transmission of signals, the delay notification sending unit, a gist that you send the delay notification including the frequency bandwidth after expansion by the frequency bandwidth extending unit.

In such a communication device, when the delay time of a signal from another communication device exceeds the allowable time that is the maximum delay time in which the time position of the signal falls within the time slot of the time slot, In view of the high possibility that the communication quality will deteriorate, a delay notification is transmitted to another communication apparatus. Thereby, the other communication apparatus can increase the transmission rate of the signal when receiving the delay notification. By increasing the transmission speed of the signal, the transmission time of the signal is shortened. As a result, collision of signals can be prevented, and further, deterioration of communication quality can be prevented. Further, when the communication device thus exceeds the allowable time, the frequency bandwidth used for signal transmission is expanded, and the expanded frequency bandwidth is notified to other communication devices. As a result, other communication devices can increase the transmission rate by expanding the frequency bandwidth used for signal transmission.

  The gist of a third aspect of the present invention is that the delay notification transmission unit transmits the delay notification including the delay time measured by the delay time measurement unit.

  As described above, the communication device transmits a delay notification including the delay time to the other communication device, so that the other communication device can set an appropriate transmission rate according to the delay time. .

According to a fourth aspect of the present invention, there is provided a modulation multi-value that increases the number of modulation multi-values of a modulation scheme used for signal transmission when the delay time measured by the delay time measurement unit exceeds the allowable time. The delay notification transmitting unit includes a value number increasing unit (modulation multilevel number increasing unit 160), and the delay notification transmitting unit transmits the delay notification including the modulation multilevel number increased by the modulation multilevel number increasing unit. To do.

  In this way, when the delay time exceeds the allowable time, the communication device increases the modulation multi-value number of the modulation scheme used for signal transmission, and the increased modulation multi-value number is transferred to another communication device. The other communication apparatuses can increase the transmission rate by increasing the number of modulation multi-values of the modulation scheme used for signal transmission.

A fifth aspect of the present invention includes a collision detection unit (collision detection unit 156) that detects a collision of the signals received by the signal reception unit, and the delay notification unit is measured by the delay time measurement unit. The delay time is transmitted when the delay time exceeds the allowable time and the collision detection unit detects the collision of the signals.

  Even if the signal delay time exceeds the allowable time, the communication quality will not be deteriorated if there is no signal collision. For this reason, communication quality deteriorates by transmitting a delay notification to another communication device only when the delay time of the signal exceeds an allowable range and a signal collision is detected. Only in this case, the transmission speed can be increased in another communication apparatus, and the processing load in the other communication apparatus is reduced.

A sixth aspect of the present invention is a communication device (wireless terminals 2A to 2D) that transmits a signal to another communication device (wireless base station 1) using a plurality of time slots obtained by dividing a communication time zone. The signal transmission unit (signal transmission processing unit 252) that transmits a signal to the other communication device using the time slot, and the delay time of the signal received by the other communication device is the signal Delay notification reception for receiving a delay notification indicating a delay of a signal transmitted from the other communication device when the time position of exceeds the allowable time which is the maximum delay time that can be accommodated in the time slot of the time slot Unit (delay notification reception processing unit 254) and a transmission rate increase unit (transmission unit) that increases the transmission rate of the signal transmitted using the time slot when the delay notification is received by the delay notification receiver. Comprising a speed increasing portion 256) and said signal transmission unit, when the delay time to transmit the signal using the next time slot of the time slots used for transmission of the signals that exceed the allowable time, the gist of the Rukoto delay the start of transmission.

In such a communication apparatus, in another communication apparatus that is a signal transmission destination, the delay time of the signal exceeds the allowable time that is the maximum delay time in which the time position of the signal falls within the time slot time zone. In this case, the signal transmission rate can be increased. By increasing the transmission speed of the signal, the transmission time of the signal is shortened. As a result, collision of signals can be prevented, and further, deterioration of communication quality can be prevented. Further, when the communication device transmits a signal using a time slot next to a time slot used for transmission of a signal whose delay time exceeds the allowable time, the communication device It is possible to prevent collision between a signal to be transmitted and a signal having a delay, and further prevent deterioration in communication quality.
According to a seventh aspect of the present invention, there is provided a communication device that transmits a signal to and from another communication device using a plurality of time slots obtained by dividing a communication time zone. And a signal transmission unit that transmits a signal to the communication device, and a delay time of a signal received by the other communication device is an allowable time in which a time position of the signal falls within a time slot of the time slot. When the delay notification is received by the delay notification receiving unit, the delay notification receiving unit that receives a delay notification indicating a signal delay transmitted from the other communication device when the delay notification is received, A transmission rate increase unit that increases a transmission rate of the signal transmitted using a time slot, the delay notification includes a frequency bandwidth used for signal transmission, and the transmission rate increase unit includes the transmission rate increase unit. The frequency bandwidth used for transmission of the gist to set the frequency bandwidth included in the delay notification.

  According to an eighth aspect of the present invention, the delay notification includes the delay time, and the transmission rate increase unit increases the transmission rate as the delay time included in the delay notification is longer. To do.

  Such a communication apparatus can set an appropriate transmission rate according to the delay time of the signal in another communication apparatus that is a signal transmission destination.

  According to a ninth aspect of the present invention, when the signal transmission unit transmits the signal using a time slot next to a time slot used for transmission of the signal whose delay time exceeds the allowable time, The gist is to delay the start of transmission.

  When a communication apparatus transmits a signal using a time slot next to a time slot used for transmission of a signal whose delay time exceeds the allowable time, the communication apparatus transmits the signal by delaying the start of transmission. It is possible to prevent collision between a signal and a signal having a delay, and further prevent deterioration in communication quality.

  In a tenth aspect of the present invention, the delay notification includes a frequency bandwidth used for signal transmission, and the transmission rate increase unit includes a frequency bandwidth used for transmission of the signal in the delay notification. The gist is to set the frequency bandwidth to be set.

  In an eleventh aspect of the present invention, the delay notification includes a modulation multi-level number of a modulation scheme used for signal transmission, and the transmission rate increase unit indicates a modulation multi-level number used for transmission of the signal. The gist is to set the modulation multi-level number included in the delay notification.

A twelfth aspect of the present invention includes a first communication device and a plurality of second communication devices, and a plurality of time slots obtained by dividing a communication time zone, and the first communication device and the plurality of second communication devices. A communication control method in a communication system for transmitting signals to and from a device, wherein the first communication device receives a signal transmitted using the time slot by the plurality of second communication devices; The first communication device measures the delay time of the received signal, and the delay time measured by the first communication device is the maximum that the time position of the signal falls within the time slot of the time slot. A delay notification indicating a signal delay when the delay time exceeds the allowable time, the second communication device that is a transmission source of the signal whose delay time exceeds the allowable time, and the delay time Transmitting to one of said second communication device that is the source of the signal transmitted using the next time slot of the time slots used for transmission of the signals that exceed the allowable time, the first communication A device extending a frequency bandwidth used for signal transmission when the measured delay time exceeds the allowable time; and the second communication device transmits the delay from the first communication device. Receiving the notification and, when the second communication device receives the delay notification, increasing the transmission rate of the signal to be transmitted using the time slot, and transmitting the delay notification in step, the first communication device, a gist that you transmit the delay notification including the frequency bandwidth after expansion by the frequency bandwidth extending unit.

  ADVANTAGE OF THE INVENTION According to this invention, degradation of the communication quality of the signal received in a communication apparatus can be prevented.

  Next, an embodiment of the present invention will be described with reference to the drawings. Specifically, (1) the configuration of the radio communication system, (2) the operation of the radio base station, (3) the operation and effect, and (4) other embodiments will be described. In the description of the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

(1) Configuration of Radio Communication System First, regarding the configuration of the radio communication system according to the embodiment of the present invention, (1.1) overall schematic configuration of radio communication system, (1.2) configuration of radio base station, (1 .3) The configuration of the wireless terminals will be described in the order.

(1.1) Overall Schematic Configuration of Radio Communication System FIG. 1 is an overall schematic configuration diagram of a radio communication system 10 according to an embodiment of the present invention.

  As shown in FIG. 1, the radio communication system 10 is a PHS radio communication system. The radio communication system 10 includes a radio base station 1, a radio terminal 2A, a radio terminal 2B, a radio terminal 2C, and a radio terminal 2D. In FIG. 1, radio terminals 2A to 2D are located in a cell 3 provided by the radio base station 1. The radio base station 1 and the radio terminals 2A to 2D communicate by time division duplex and time division multiplexing.

  Prior to communication with the wireless terminals 2A to 2D, the wireless base station 1 assigns different time slots in the frame to the wireless terminals 2A to 2D.

    FIG. 2 is a diagram illustrating a frame configuration. As shown in FIG. 2, the frame includes a downlink time zone used for communication in the downlink direction (direction from the radio base station 1 toward the radio terminals 2A to 2D), and an uplink direction (radio terminal 2A) following the downlink time zone. To 2D to the radio base station 1), the downlink time slot is divided into four downlink time slots D1 to D4, and the uplink time slot is divided into four downlink time slots U1 to U1. It is divided into U4.

  In the initial state, the radio base station 1 assigns the downlink time slot D1 and the uplink time slot U1 to the radio terminal 2A, and assigns the downlink time slot D2 and the uplink time slot U2 to the radio terminal 2B. Further, the radio base station 1 assigns the downlink time slot D3 and the uplink time slot U3 to the radio terminal 2C, and assigns the downlink time slot D4 and the uplink time slot U4 to the radio terminal 2D. The radio terminals 2A to 2D receive signals from the radio base station 1 using the assigned downlink time slots, and transmit signals to the radio base station 1 using the assigned uplink time slots.

  In the following, it is assumed that the radio base station 1 and the radio terminals 2A to 2D transmit audio signals, and the amount of audio data transmitted using each time slot is fixed.

(1.2) Configuration of Radio Base Station Next, regarding the configuration of the radio base station 1, (1.2.1) schematic configuration of the radio base station, (1.2.2) detailed configuration of the radio base station. explain.

(1.2.1) Schematic Configuration of Radio Base Station FIG. 3 is a schematic configuration diagram of the radio base station 1. As shown in FIG. 3, the radio base station 1 includes a control unit 102, a storage unit 103, a wired communication unit 104, an antenna 106, a radio reception unit (RX unit) 108, a demodulation unit 110, a decoding unit 112, a coding unit 114, A modulation unit 116 and a wireless transmission unit (TX unit) 118 are included.

  The control unit 102 is configured by a CPU, for example, and controls various functions provided in the radio base station 1. The storage unit 103 is configured by a memory, for example, and stores various types of information used for control and the like in the radio base station 1.

  The wired communication unit 104 communicates with a gateway server or the like in an upper network (not shown).

  The RX unit 108 receives each signal from the wireless terminals 2A to 2D, which is a signal in a predetermined reception frequency band, via the antenna 106, and outputs it to the demodulation unit 110 each time the signal is received. Every time each signal is input, the demodulation unit 110 demodulates the signal and outputs it to the decoding unit 112. Each time the decoding unit 112 inputs the signal demodulated by the decoding unit 112, the decoding unit 112 decodes the demodulated signal and outputs the obtained reception data to the control unit 102.

  The encoding unit 114 receives transmission data output from the control unit 102. Further, the encoding unit 114 encodes transmission data and outputs the obtained signal to the modulation unit 116. Modulation section 116 modulates the input signal using a predetermined modulation method, and outputs the modulated signal to TX section 118. The TX unit 118 transmits the input signal to the radio terminals 2A to 2D via the antenna 106.

(1.2.2) Detailed Configuration of Radio Base Station Next, a detailed configuration of the radio base station 1, specifically, a functional block configuration of the control unit 102 will be described. FIG. 4 is a functional block configuration diagram of the control unit 102 of the radio base station 1.

  As shown in FIG. 4, the control unit 102 includes a signal reception processing unit 152, a delay time measurement unit 154, a collision detection unit 156, a frequency bandwidth extension unit 158, a modulation multilevel number increase unit 160, and a delay notification transmission processing unit 162. including.

  The signal reception processing unit 152 receives each reception data from the decoding unit 112. The delay time measuring unit 154 measures the delay time for each signal from the wireless terminals 2A to 2D corresponding to each received data.

  If the delay time exceeds the allowable time, which is the maximum delay time that the time position of the corresponding signal fits in the time slot of the upstream time slot, in other words, the time position of the signal is the time slot of the upstream time slot. When deviating backward, the collision detection unit 156 transmits a signal transmitted using the uplink time slot next to the uplink time slot used for transmission of the out-of-time-slot delayed signal for the signal (out-of-time-slot delayed signal) ( Next collision signal is detected.

  When the collision detection unit 156 detects a collision between the delayed signal out of time slot and the next transmission signal, the frequency bandwidth expansion unit 158 expands the frequency bandwidth used for signal transmission. Further, the frequency bandwidth extension unit 158 further increases the frequency bandwidth when the RX unit 108 receives a signal from the transmission source of the out-of-slot-delayed signal or the transmission source of the next transmission signal to the frequency bandwidth after the extension. Change to

  Alternatively, when the collision detection unit 156 detects a collision between the delayed signal out of time slot and the next transmission signal, the modulation multi-level number increasing unit 160 increases the modulation multi-level number of the modulation scheme used for signal transmission. Let Further, the modulation multi-level number increasing unit 160 determines the demodulation method used when the demodulation unit 110 demodulates the signal from the transmission source of the out-of-slot-delayed delay signal or the transmission source of the next transmission signal. Change to a demodulation method paired with a modulation method corresponding to the number.

  When the frequency bandwidth used for signal transmission is expanded by the frequency bandwidth expansion unit 158, the delay notification transmission processing unit 162 includes the expanded frequency bandwidth information, the delay time information, and the out of time slot. A delay notification including a unique word (described later) that is identification information of the wireless terminal that is the transmission source of the delay signal is generated. Further, the delay notification transmission processing unit 162 transmits any one of the wireless terminals 2A to 2D that is the transmission source of the out-of-slot-delayed delay signal or one of the wireless terminals 2A to 2D that is the transmission source of the next transmission signal. The generated delay notification is output to the encoding unit 114.

  On the other hand, when the modulation multi-level number of the modulation scheme used for signal transmission is increased by the modulation multi-level number increasing unit 160, the delay notification transmission processing unit 162 includes the increased modulation multi-level number information, the delay A delay notification including time information and a unique word of the wireless terminal that is the transmission source of the out-of-slot delay signal is generated. Furthermore, the delay notification transmission processing unit 162 is one of the wireless terminals 2A to 2D that are the transmission source of the out-of-slot-delayed delay signal, or the up-time slot next to the up-time slot used for transmission of the out-of-slot-out delay signal. One of the wireless terminals 2A to 2D that is the transmission source of the signal transmitted using is specified as the transmission destination, and the generated delay notification is output to the encoding unit 114.

  The encoding unit 114 encodes the delay notification data. The modulation unit 116 modulates the signal obtained by encoding. The TX unit 118 transmits the modulated signal via the antenna 106 using a downlink time slot assigned to any one of the transmission destination wireless terminals 2A to 2D that is the designated transmission source.

(1.3) Configuration of Radio Terminal Next, configurations of the radio terminals 2A to 2D will be described in the order of (1.3.1) schematic configuration of the radio terminal and (1.3.2) detailed configuration of the radio terminal. .

(1.3.1) Schematic Configuration of Radio Terminal FIG. 5 is a schematic configuration diagram of the radio terminal 2A. As illustrated in FIG. 5, the wireless terminal 2A includes a control unit 202, a storage unit 203, a wireless communication unit 206, an antenna 208, a monitor 210, a microphone 212, a speaker 214, and an operation unit 216. The wireless terminals 2B to 2D have the same configuration as the wireless terminal 2A.

  The control unit 202 is configured by a CPU, for example, and controls various functions provided in the wireless terminal 2A. The storage unit 203 is configured by a memory, for example, and stores various information used for control and the like in the wireless terminal 2A.

  The wireless communication unit 206 includes an RF circuit, a baseband circuit, etc., performs modulation and demodulation, encoding and decoding, etc., and transmits and receives wireless signals via the antenna 208.

  The monitor 210 displays an image received via the control unit 202 and displays operation details (such as an input telephone number and an address). The microphone 212 collects sound and outputs sound data based on the collected sound to the control unit 202. The speaker 214 outputs sound based on the sound data acquired from the control unit 102.

  The operation unit 216 is configured by a numeric keypad, function keys, and the like, and is an interface used for inputting user operation details.

  FIG. 6A is a diagram illustrating a configuration related to reception by the wireless communication unit 206. As shown in FIG. 6, the wireless communication unit 206 includes an RF mixer 222, a switch 224, an IF filter 226, an IF filter 228, and an IF mixer 230.

  The RF mixer 222 mixes the input carrier signal and the RF local signal (local oscillation signal), and outputs a first intermediate frequency signal. The switch 224 operates under the control of the control unit 202 described later. The switch 224 switches between when the first intermediate frequency signal output from the RF mixer 222 is output to the IF filter 226 and when it is output to the IF filter 228.

  The IF filter 226 filters in the 300 kHz band. On the other hand, the IF filter 228 filters in the 900 kHz band. Note that the communication processing unit 206 may include one IF filter whose sampling frequency is variable instead of the IF filters 226 and 228.

  The IF mixer 230 mixes the output signal of the IF filter 226 or the output signal of the IF filter 228 and the IF local signal (local oscillation signal), and outputs a second intermediate frequency signal.

  FIG. 6B is a diagram illustrating a configuration related to transmission of the wireless communication unit 206. As illustrated in FIG. 6, the wireless communication unit 206 includes an IF mixer 232, a switch 234, an IF filter 236, an IF filter 238, and an RF mixer 240.

  IF mixer 232 mixes a first intermediate frequency signal input from a modulation unit (not shown) in radio communication unit 206 and an IF local signal (local oscillation signal), and outputs a second intermediate frequency signal. To do. The switch 234 operates under the control of the control unit 202 to be described later, and switches between when the second intermediate frequency signal output from the IF mixer 232 is output to the IF filter 236 and when it is output to the IF filter 238.

  The IF filter 236 filters in the 300 kHz band. On the other hand, the IF filter 238 filters in the 900 kHz band. As described above, the communication processing unit 206 may include one IF filter whose sampling frequency is variable instead of the IF filters 236 and 238.

  The RF mixer 240 mixes an RF local signal (local oscillation signal) with the output signal of the IF filter 236 or the output signal of the IF filter 238, and outputs a carrier wave signal.

(1.3.2) Detailed Configuration of Wireless Terminal Next, a detailed configuration of the wireless terminal 2A, specifically, a functional block configuration of the control unit 202 will be described. FIG. 7 is a functional block configuration diagram of the control unit 202 of the wireless terminal 2A. Note that the control unit 202 of the wireless terminals 2B to 2D has the same configuration as the control unit 202 of the wireless terminal 2A.

  As shown in FIG. 7, the control unit 202 includes a signal transmission processing unit 252, a delay notification reception processing unit 254, and a transmission rate increase unit 256.

  The signal transmission processing unit 252 performs processing for transmitting a signal toward the radio base station 1 using an uplink time slot assigned to the own radio terminal. Specifically, the signal transmission processing unit 252 outputs data to be transmitted to the radio communication unit 206 in the uplink time slot time zone assigned to the own radio terminal. When the data is input, the wireless communication unit 206 performs encoding, modulation, and mixing of carrier signals, and transmits the result to the wireless base station 1 via the antenna 208.

  The delay notification reception processing unit 254 performs processing for receiving a delay notification transmitted from the radio base station 1 using a downlink time slot assigned to the own radio terminal. Specifically, the delay notification reception processing unit 254 inputs the delay notification output from the wireless communication unit 206 in the time slot of the downlink time slot assigned to the own wireless terminal.

  The transmission rate increasing unit 256 increases the transmission rate of the signal in the uplink time slot. Specifically, the transmission rate increasing unit 256 extracts the expanded frequency bandwidth information or the increased modulation multi-level number information and the unique word included in the delay notification.

  When the information on the expanded frequency bandwidth is extracted, the transmission speed increasing unit 256 uses the wireless communication unit 206 to transmit the signal in the uplink time slot based on the information on the expanded frequency bandwidth. The frequency bandwidth to be changed is changed to the expanded frequency bandwidth. At this time, the transmission speed increasing unit 256 connects the switch 224 in the wireless communication unit 206 to the IF filter 228 side and connects the switch 234 to the IF filter 238 side.

  On the other hand, when the information on the increased modulation multi-level number is extracted, the transmission rate increase unit 256 performs signal transmission in the uplink time slot in the radio communication unit 206 based on the information on the increased modulation multi-level number. The modulation multi-level number of the modulation scheme used for the transmission of is changed to the increased modulation multi-level number.

  Further, the transmission rate increasing unit 256 determines whether or not the extracted unique word is the unique word of the own wireless terminal. When the extracted unique word is not the unique word of the own radio terminal, the own radio terminal transmits the next transmission signal transmitted using the uplink time slot next to the uplink time slot used for transmission of the out-of-slot delayed signal. The sender. In this case, the transmission rate increasing unit 256 subsequently delays the start when transmitting a signal using an uplink time slot assigned to the own wireless terminal.

(2) Operation of Radio Communication System Next, the operation of the radio communication system 10 will be described. In the following, it is assumed that in the initial state, the signal transmission in the uplink time slot uses a frequency bandwidth of 300 kHz band and a modulation method of π / 4 shift QPSK. Hereinafter, a first embodiment in which the frequency bandwidth used for signal transmission in the uplink time slot is changed, and a second embodiment in which the modulation multi-level number of the modulation scheme used for signal transmission in the uplink time slot is changed. Will be explained.

(2.1) First Example FIG. 8 is a flowchart showing the operation of the radio base station 1 in the first example.

  In step S101, the radio base station 1 receives signals transmitted from the radio terminals 2A to 2D using uplink time slots. Thereafter, the control unit 102 inputs received data corresponding to the signal from the decoding unit 112. Further, the control unit 102 measures a delay time for each signal from the wireless terminals 2A to 2D corresponding to each received data.

  Specifically, the control unit 102 detects the time position of the unique word (UW) included in the received data. The time position is represented by, for example, a time based on the timing at the beginning of the upstream time slot.

  FIG. 9 is a diagram illustrating a configuration of received data. The reception data shown in FIG. 6 has a bit length of 240 bits. The received data includes, in order from the top, a 4-bit long ramp time for transient response (R), a 2-bit long start symbol (SS), a 6-bit long preample (PR), a 16-bit long unique word (UW). ), 180-bit information, 16-bit CRC (Cyclic Redundancy Check), and 16-bit guard.

  Further, the control unit 102 measures the time difference between the detected time position of the unique word and the time position of the unique word when the signal is not delayed as a delay time. Information on the time position of the unique word when the signal is not delayed is stored in the storage unit 103, for example.

  In step S102, the control unit 102 determines whether or not the measured delay time exceeds an allowable time that is the maximum delay time in which the time position of the corresponding signal falls within the time slot of the uplink time slot. The information on the allowable time is stored in the storage unit 103, for example.

  When the delay time exceeds the allowable time, that is, when the time position of the signal deviates behind the time slot of the upstream time slot, in step S103, the control unit 102 exceeds the allowable time. It is determined whether or not a signal (out-of-time slot delayed signal) collides with a signal (next transmission signal) transmitted in an upstream time slot next to an upstream time slot used for transmission of the out-of-time slot delayed signal. .

  Specifically, the control unit 102 calculates a time difference between the time position of the unique data included in the received data corresponding to the delayed signal out of time slot and the time position of the unique data included in the received data corresponding to the next transmission signal. calculate. Furthermore, the control unit 102 determines whether or not the calculated time difference is less than a predetermined time. Here, the predetermined time is a minimum time difference at which the delayed signal out of the time slot and the next transmission signal do not collide with each other. Information on the predetermined time is stored in the storage unit 103, for example.

  When the time difference is less than the predetermined time, that is, when the out-of-slot delayed signal and the next transmission signal collide, in step S104, the control unit 102 controls the RX unit 108 to transmit the signal in the upstream time slot. The frequency bandwidth (upstream frequency bandwidth) used for the setting is changed from the frequency bandwidth of 300 kHz band to the frequency bandwidth of 900 kHz band.

  FIG. 10 is a diagram showing a distribution of carrier frequencies used by a frequency bandwidth of 300 kHz and a frequency bandwidth of 900 kHz. As shown in FIG. 10, a frequency bandwidth of 300 kHz is used from 1893.6 MHz to 1919.4 MHz. On the other hand, a frequency band from 1879.8 MHz to 1893.6 MHz wider than the frequency bandwidth of 300 kHz is used as the frequency band of 900 kHz. As a result, a state in which the frequency bandwidth of the 300 kHz band and the frequency bandwidth of the 900 kHz band are not mixed is avoided, and a group delay occurs due to the later assignment of a wide frequency bandwidth of 900 kHz band to the channel assignment in the 300 kHz step. It is avoided. Therefore, the frequency bandwidth can be smoothly extended from the frequency bandwidth of 300 kHz to the frequency bandwidth of 900 kHz.

  Again, referring back to FIG. In step S105, the control unit 102, the expanded frequency bandwidth information, the delay time information, and the unique word in the received data corresponding to the out-of-slot delayed signal, in other words, the out-of-slot-out delayed signal. A delay notification including the unique word of the wireless terminal that is the transmission source is generated. Further, the control unit 102 designates any one of the wireless terminals 2A to 2D that is the transmission source of the out-of-slot delayed signal or one of the wireless terminals 2A to 2D that is the transmission source of the next transmission signal as the transmission destination. The generated delay notification is output to the encoding unit 114. Thereafter, the radio base station 1 transmits a signal corresponding to the delay notification using the downlink time slot assigned to any one of the radio terminals 2A to 2D as the transmission destination.

  On the other hand, if it is determined in step S102 that the delay time is equal to or shorter than the allowable time, or if it is determined in step S103 that no signal collision has occurred, in step S106, the control unit 102 The frequency bandwidth is maintained at a frequency bandwidth of 300 kHz.

  FIG. 11 is a flowchart showing the operation of the wireless terminal that receives the delay notification transmitted from the wireless base station 1 by the operation shown in FIG.

  In step S201, any of the wireless terminals 2A to 2D receives a signal corresponding to the delay notification transmitted using the downlink time slot. Thereafter, the control unit 202 inputs a delay notification corresponding to the signal from the wireless communication unit 206.

  In step S202, the control unit 202 attempts to extract information on the expanded frequency bandwidth included in the delay notification. Here, since the information on the expanded frequency bandwidth is included in the delay notification, the control unit 202 can extract the information on the expanded frequency bandwidth. When the information on the expanded frequency bandwidth is extracted, the control unit 202 determines whether or not the uplink frequency bandwidth can be expanded. For example, when the switch 234 in the communication processing unit 206 is already connected to the IF filter 238 side, the uplink frequency bandwidth cannot be further expanded. In this case, the control unit 202 determines that the uplink frequency bandwidth cannot be expanded.

  When the upstream frequency bandwidth can be expanded, in step S203, the control unit 202 connects the switch 224 in the communication processing unit 206 to the IF filter 228 side and connects the switch 234 to the IF filter 238 side. As a result, the connection destination is switched from the 300 kHz band IF filter 226 to the 900 kHz band IF filter 228, and from the 300 kHz band IF filter 236 to the 900 kHz band IF filter 238. Further, the IF filter 238 in the 900 kHz band performs signal sampling, and the frequency bandwidth used for signal transmission in the uplink time slot is expanded. Furthermore, the transmission rate of signals using uplink time slots increases.

  In step S205, the control unit 202 extracts a unique word included in the delay notification. Furthermore, the control unit 202 determines whether or not the extracted unique word is a unique word of the own wireless terminal.

  When the extracted unique word is the unique word of the own radio terminal, the signal transmitted by the own radio terminal using the uplink time slot is a delayed signal out of the time slot in the radio base station 1. In this case, in step S207, any of the wireless terminals 2A to 2D that has received the delay notification transmits a signal in an uplink time slot using the expanded frequency bandwidth. As a result, the transmission rate of the signal using the uplink time slot increases.

  For example, in FIG. 12A, in the radio base station 1, the time position (reception window # 1) of the signal transmitted using the uplink time slot U1 from the radio terminal 2A is the time zone of the uplink time slot U1. It has come back backwards. That is, in the radio base station 1, the delay time of the signal from the radio terminal 2A exceeds the allowable time. The reception window # 1 overlaps with the time position (reception window # 2) of the signal transmitted using the uplink time slot U2 from the wireless terminal 2B. That is, in the radio base station 1, the signal from the radio terminal 2A and the signal from the radio base station 2B collide.

  In such a case, the radio terminal 2A extends the frequency bandwidth used for signal transmission in the uplink time slot U1. As a result, the transmission rate of the signal using the uplink time slot U1 increases. As described above, the audio signal is transmitted using the time slot between the radio base station 1 and the radio terminal 2A, and the amount of audio data transmitted using one time slot is fixed. For this reason, when the transmission rate of the signal using the uplink time slot U1 increases, the reception window # 1 of the signal transmitted using the uplink time slot U1 is shortened as shown in FIG. The That is, the transmission time of the signal transmitted using the uplink time slot U1 is shortened. As a result, in the radio base station 1, collision between the signal from the radio terminal 2A and the signal from the radio terminal 2B is prevented, and further, deterioration of communication quality is prevented.

  On the other hand, if it is determined in step S205 that the extracted unique word is not the unique word of the own radio terminal, the signal transmitted by the own radio terminal using the uplink time slot is transmitted to the next transmission signal in the radio base station 1. It has become. In this case, in step S206, the control unit 202 delays the start of signal transmission using the uplink time slot. Specifically, the control unit 202 delays the timing of data output to the encoding unit 114 from the normal time. At this time, the control unit 202 delays the output timing as the delay time included in the delay notification is longer.

  Thereafter, in step S207, any of the wireless terminals 2A to 2D that has received the delay notification performs a signal in the uplink time slot using the expanded frequency bandwidth at the delayed transmission start timing. As a result, the transmission rate of the signal using the uplink time slot increases.

  For example, in FIG. 13A, as in FIG. 12A, in the radio base station 1, the reception window # 1 deviates behind the time slot of the uplink time slot U1. That is, in the radio base station 1, the delay time of the signal from the radio terminal 2A exceeds the allowable time. Reception window # 1 overlaps with reception window # 2. That is, in the radio base station 1, the signal from the radio terminal 2A and the signal from the radio base station 2B collide.

  In such a case, the radio terminal 2B extends the frequency bandwidth used for signal transmission in the uplink time slot U2. Thereby, the transmission rate of the signal using the uplink time slot U2 increases. Also, the wireless terminal 2B delays the start of signal transmission using the uplink time slot from the normal time. As the transmission rate of the signal using the uplink time slot U2 increases and the start of transmission of the signal is delayed, as shown in FIG. 13B, the signal transmitted using the uplink time slot U2 As reception window # 2 is shortened, the beginning of reception window # 2 moves backward. That is, the transmission time of the signal transmitted using the uplink time slot U2 is shortened and moves backward. As a result, in the radio base station 1, collision between the signal from the radio terminal 2A and the signal from the radio terminal 2B is prevented, and further, deterioration of communication quality is prevented.

  If the uplink frequency bandwidth is not expandable in step S202, in step S204, the control unit 202 determines that the switch 224 in the communication processing unit 206 is connected to the IF filter 226 side, and that the switch 234 is an IF filter. The state connected to the 236 side is maintained. In this case, in step S207, signal transmission in the uplink time slot is performed using the frequency bandwidth that has not been expanded.

(2.2) Second Embodiment FIG. 14 is a flowchart showing the operation of the radio base station 1 in the second embodiment. The operations in steps S301 to S303 in FIG. 14 are the same as the operations in steps S101 to S103 in FIG.

  When it is determined in step S303 that the delayed signal out of time slot and the next transmission signal collide, in step S304, the control unit 102 modulates the modulation multi-level number of the modulation scheme used for signal transmission in the uplink time slot. And the modulation scheme (uplink modulation scheme) used for signal transmission in the uplink time slot is set to 16QAM. Here, the transmission rate when 16QAM is used is twice the transmission rate when π / 4 shift QPSK, which is the modulation scheme in the initial state, is used.

  In step S305, the control unit 102 determines the increased modulation multilevel information, the delay time information, and the unique word in the received data corresponding to the out-of-slot-delayed signal, in other words, out-of-slot-out delayed signal. A delay notification including the unique word of the wireless terminal that is the transmission source of is generated. Further, the control unit 102 designates any one of the wireless terminals 2A to 2D that is the transmission source of the out-of-slot delayed signal or one of the wireless terminals 2A to 2D that is the transmission source of the next transmission signal as the transmission destination. The generated delay notification is output to the encoding unit 114. Thereafter, the radio base station 1 transmits a signal corresponding to the delay notification using the downlink time slot assigned to any of the radio terminals 2A to 2D designated as the transmission destination.

  On the other hand, if it is determined in step S302 that the delay time is equal to or shorter than the allowable time, or if it is determined in step S303 that no signal collision has occurred, in step S306, the control unit 102 The modulation scheme is maintained at π / 4 shift QPSK.

  FIG. 15 is a flowchart showing the operation of the radio terminal that receives the delay notification transmitted from the radio base station 1 by the operation shown in FIG.

  In step S401, one of the wireless terminals 2A to 2D that is the transmission destination of the delay notification receives a signal corresponding to the delay notification transmitted using the downlink time slot. Thereafter, the control unit 202 inputs a delay notification corresponding to the signal from the wireless communication unit 206.

  In step S <b> 402, the control unit 202 attempts to extract information on the increased modulation multilevel number included in the delay notification. Here, since the information of the increased modulation multi-level number is included in the delay notification, the control unit 202 can extract the information of the increased modulation multi-level number. When the increased modulation multilevel number is extracted, the control unit 202 determines whether or not the uplink modulation multilevel number (upstream modulation multilevel number) can be increased. For example, when the uplink modulation scheme is already 16QAM, the number of uplink modulation multi-levels cannot be increased any more. In this case, the control unit 202 determines that the uplink modulation multilevel number cannot be increased.

  If the uplink modulation multilevel number can be increased, in step 403, the control unit 202 increases the modulation multilevel number to the increased modulation multilevel number included in the delay notification, and sets the uplink modulation scheme to 16QAM. To do. As a result, the modulation multi-level number of the modulation scheme increases, and further, the transmission rate of the signal using the uplink time slot increases.

  In step S405, the control unit 202 extracts a unique word included in the delay notification. Furthermore, the control unit 202 determines whether or not the extracted unique word is a unique word of the own wireless terminal.

  When the extracted unique word is the unique word of the own radio terminal, the signal transmitted by the own radio terminal using the uplink time slot is a delayed signal out of the time slot in the radio base station 1. In this case, in step S407, any of the wireless terminals 2A to 2D that has received the delay notification transmits a signal in an uplink time slot using 16QAM that is a modulation scheme corresponding to the increased modulation multilevel number. Do.

  As a result, the transmission rate of the signal using the uplink time slot increases. As described above, an audio signal is transmitted, and the amount of audio data transmitted using one time slot is fixed. For this reason, when the transmission rate is increased, the signal transmission time is shortened. As a result, in the radio base station 1, a collision between the signal from the radio terminal that is the source of the out-of-slot delayed signal and the signal from the radio terminal that is the source of the next transmission signal is prevented. Deterioration is prevented.

  On the other hand, if it is determined in step S405 that the extracted unique word is not the unique word of the own wireless terminal, the signal transmitted by the own wireless terminal using the uplink time slot is transmitted to the next transmission signal in the wireless base station 1. It has become. In this case, in step S406, the control unit 202 delays the start of signal transmission using the uplink time slot. Thereafter, in step S407, any one of the wireless terminals 2A to 2D that has received the delay notification uses the 16QAM, which is a modulation scheme corresponding to the increased modulation multi-level, at the delayed transmission start timing. Transmits the signal in the slot.

  As a result, the transmission speed of the signal using the uplink time slot is increased, and the transmission time is shortened and moved backward. As a result, in the radio base station 1, a collision between the signal from the radio terminal that is the source of the out-of-slot delayed signal and the signal from the radio terminal that is the source of the next transmission signal is prevented. Deterioration is prevented.

  If it is determined in step S402 that the uplink modulation multilevel number cannot be increased, the control unit 202 maintains the uplink modulation scheme at π / 4 shift QPSK in step S404. Thereafter, in step S407, signals are transmitted in the uplink time slot using π / 4 shift QPSK which is the maintained modulation scheme.

(3) Operation / Effect In the radio communication system 10 according to the embodiment of the present invention, the radio base station 1 allows the delay time of a signal transmitted from any of the radio terminals 2A to 2D using an uplink time slot to be allowed. Considering that the communication quality of the signal is likely to deteriorate when it exceeds the time, any of the wireless terminals 2A to 2D that are the transmission source of the signal and the uplink time used for transmission of the signal A delay notification is transmitted to one of the radio terminals 2A to 2D that is a transmission source of a signal transmitted using the next uplink time slot of the slot. The delay notification includes information on the expanded frequency bandwidth or information on the number of modulation multilevels after the increase.

  On the other hand, any one of the wireless terminals 2A to 2D that has received the delay notification increases the frequency bandwidth used for signal transmission in the uplink time slot according to the expanded frequency bandwidth information included in the delay notification. . Alternatively, any one of the wireless terminals 2A to 2D that has received the delay notification uses the modulation scheme of the modulation scheme used for signal transmission in the uplink time slot according to the information on the increased modulation multi-level number included in the delay notification. Increase the number of values. Thereby, the transmission speed of the signal using the uplink time slot is increased, and the transmission time of the signal is shortened. Furthermore, collision of signals is prevented, and deterioration of communication quality can be prevented.

  Further, only when a signal collision occurs in the radio base station 1, the radio base station 1 transmits a delay notification. That is, only when the signal communication quality deteriorates in the radio base station 1, the transmission rate can be increased in the radio terminal, and the processing burden on the radio terminal is reduced.

  In addition, when any of the wireless terminals 2A to 2D that has received the delay notification is the transmission source of the next transmission signal, the transmission start of the signal is delayed than usual. As a result, it is possible to prevent a collision between a signal transmitted by any of the wireless terminals 2A to 2D that has received the delay notification and a signal in which a delay has occurred, and further prevent deterioration in communication quality. It becomes.

(4) Other Embodiments As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  Specifically, any of the wireless terminals 2A to 2D that have received the delay notification may increase the transmission rate of the signal using the uplink time slot as the delay time included in the delay notification is longer. .

  In this case, the communication processing unit 206 of any one of the wireless terminals 2A to 2D that has received the delay notification further adds an IF filter in another frequency band in addition to the IF filter 226 in the 300 kHz band and the IF filter 228 in the 900 kHz band. Including.

  Any of the wireless terminals 2A to 2D that has received the delay notification connects the 300 kHz band IF filter 226 and the 900 kHz band IF filter 228 when the delay time is shorter than a predetermined time. . On the other hand, any of the wireless terminals 2A to 2D that have received the delay notification, in addition to the 300 kHz band IF filter 226 and the 900 kHz band IF filter 228, when the delay time is longer than a predetermined time. Further, an IF filter of another frequency band is connected to further increase the signal transmission rate using the uplink time slot.

  Alternatively, any of the wireless terminals 2A to 2D that has received the delay notification sets the modulation scheme used for signal transmission in the uplink time slot to 16QAM when the delay time is shorter than a predetermined time. . On the other hand, any of the wireless terminals 2A to 2D that has received the delay notification sets the modulation scheme used for signal transmission in the uplink time slot to 64QAM when the delay time is shorter than a predetermined time. Further, the transmission rate of the signal using the uplink time slot is further increased.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

1 is an overall schematic configuration diagram of a wireless communication system according to an embodiment of the present invention. It is a figure which shows the structure of the flame | frame which concerns on embodiment of this invention. It is a schematic block diagram of the radio base station which concerns on embodiment of this invention. It is a functional block block diagram of the control part in the wireless base station based on embodiment of this invention. It is a schematic block diagram of the radio | wireless terminal which concerns on embodiment of this invention. It is a block diagram regarding reception and transmission of the radio | wireless communication part in the radio | wireless terminal based on embodiment of this invention. It is a functional block block diagram of the control part in the radio | wireless terminal based on embodiment of this invention. It is a flowchart which shows the operation | movement of the radio base station in the 1st Example which concerns on embodiment of this invention. It is a figure which shows the structure of the reception data which concern on embodiment of this invention. It is a figure which shows an example of distribution of the carrier frequency which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement of the radio | wireless terminal in 1st Example which concerns on embodiment of this invention. It is a figure which shows the 1st example of the transmission rate increase which concerns on embodiment of this invention. It is a figure which shows the 2nd example of the transmission rate increase which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement of the wireless base station in 2nd Example which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the radio | wireless terminal in 2nd Example which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wireless base station, 2A-2C ... Wireless terminal, 3 ... Cell, 10 ... Wireless communication system, 102 ... Control part, 103 ... Memory | storage part, 104 ... Wired communication part, 106 ... Antenna, 108 ... RX part, 110 ... Demodulation unit 112 ... decoding unit 114 ... coding unit 116 ... modulation unit 118 ... TX unit 152 ... signal reception processing unit 154 ... delay time measurement unit 156 ... collision detection unit 158 ... frequency band extension unit, 160: Modulation multi-level number increasing unit 162: Delay notification transmission processing unit 202 ... Control unit 203 ... Storage unit 206 ... Wireless communication unit 208 ... Antenna 210 ... Monitor 212 ... Microphone 214 ... Speaker 216 , Operation unit, 222, RF mixer, 224, switch, 226, IF filter, 228, IF filter, 230, IF mixer, 232, IF mixer, 234, switch, 23 ... IF filter, 238 ... IF filter, 240 ... RF mixer, 252 ... signal transmission processing section, 254 ... delay notification receiving processing unit, 256 ... transmission rate increase portion

Claims (12)

A first communication device and a plurality of second communication devices are used to transmit signals between the first communication device and the plurality of second communication devices using a plurality of time slots obtained by dividing a communication time zone. A communication system to perform,
The first communication device is
A signal receiving unit that receives signals transmitted using the time slots by the plurality of second communication devices;
A delay time measuring unit for measuring a delay time of the signal received by the signal receiving unit;
A delay indicating the delay of the signal when the delay time measured by the delay time measurement unit exceeds an allowable time that is a maximum delay time in which the time position of the signal falls within the time slot of the time slot. The second communication device that is the transmission source of the signal whose delay time exceeds the allowable time, and the time slot used for transmission of the signal whose delay time exceeds the allowable time A delay notification transmitter for transmitting to any of the second communication devices that are the transmission source of a signal transmitted using a time slot ;
When the delay time measured by the delay time measurement unit exceeds the allowable time, a frequency bandwidth extension unit that extends a frequency bandwidth used for signal transmission, and
The second communication device is
A delay notification receiver for receiving the delay notification from the first communication device;
A transmission rate increasing unit that increases the transmission rate of the signal transmitted using the time slot when the delay notification is received by the delay notification receiving unit ;
The delay notification transmission section, a communication system that transmits the delay notice including the frequency bandwidth after expansion by the frequency bandwidth extending unit. A communication device that transmits signals to and from a plurality of other communication devices using a plurality of time slots obtained by dividing a communication time zone,
A signal receiving unit for receiving a signal transmitted by using the time slot by the plurality of other communication devices;
A delay time measuring unit for measuring a delay time of the signal received by the signal receiving unit;
When the delay time measured by the delay time measurement unit exceeds an allowable time that is the maximum time in which the time position of the signal falls within the time slot of the time slot, a delay notification indicating a signal delay is sent. The other communication device that is the transmission source of the signal whose delay time exceeds the allowable time, and the time slot next to the time slot used for transmission of the signal whose delay time exceeds the allowable time a delay notification transmission unit that transmits to the one of the other communication apparatus which is the source of the signal to be transmitted using,
When the delay time measured by the delay time measurement unit exceeds the allowable time, a frequency bandwidth extension unit that extends a frequency bandwidth used for signal transmission, and
The delay notification transmission unit that sends the delayed notification including the frequency bandwidth after expansion by the frequency bandwidth extension unit communication apparatus.   The communication apparatus according to claim 2, wherein the delay notification transmission unit transmits the delay notification including the delay time measured by the delay time measurement unit. When the delay time measured by the delay time measurement unit exceeds the allowable time, the modulation multi-value increase unit for increasing the modulation multi-value number of the modulation scheme used for signal transmission,
The communication apparatus according to claim 2 or 3 , wherein the delay notification transmission unit transmits the delay notification including the modulation multi-level number increased by the modulation multi-level increase unit. A collision detection unit for detecting a collision of the signals received by the signal reception unit;
The delay notification unit transmits the delay notification when the delay time measured by the delay time measurement unit exceeds the allowable time and the collision detection unit detects a collision of the signals. communication apparatus according to any one of claims 2 to 4. A communication device that transmits signals to and from other communication devices using a plurality of time slots obtained by dividing a communication time zone,
A signal transmission unit for transmitting a signal to the other communication device using the time slot;
When the delay time of the signal received in the other communication device exceeds an allowable time that is the maximum delay time in which the time position of the signal falls within the time slot of the time slot, from the other communication device A delay notification receiver for receiving a delay notification indicating a signal delay to be transmitted;
A transmission rate increasing unit that increases the transmission rate of the signal transmitted using the time slot when the delay notification is received by the delay notification receiving unit ;
The signal transmission unit, when the delay time to send the next of said signal using a time slot of the time slots used for transmission of the signals that exceed the allowable time, the communication device that delays the start of transmission. A communication device that transmits signals to and from other communication devices using a plurality of time slots obtained by dividing a communication time zone,
A signal transmission unit for transmitting a signal to the other communication device using the time slot;
When the delay time of the signal received in the other communication device exceeds an allowable time that is the maximum delay time in which the time position of the signal falls within the time slot of the time slot, from the other communication device A delay notification receiver for receiving a delay notification indicating a signal delay to be transmitted;
A transmission rate increasing unit for increasing the transmission rate of the signal transmitted using the time slot when the delay notification is received by the delay notification receiving unit;
With
The delay notification includes a frequency bandwidth used for signal transmission,
The transmission speed increasing unit is a communication device that sets a frequency bandwidth used for transmitting the signal to a frequency bandwidth included in the delay notification. The delay notification includes the delay time,
The communication apparatus according to claim 6 or 7 , wherein the transmission rate increasing unit increases the transmission rate as the delay time included in the delay notification is longer. The signal transmission unit, when the delay time to transmit the signal using the next time slot of the time slots used for transmission of the signals that exceed the allowable time, according to claim 7 to delay the start of transmission Communication equipment. The delay notification includes a frequency bandwidth used for signal transmission,
The communication apparatus according to claim 6 , wherein the transmission rate increase unit sets a frequency bandwidth used for transmitting the signal to a frequency bandwidth included in the delay notification. The delay notification includes a modulation multi-level number of a modulation scheme used for signal transmission,
The communication apparatus according to claim 6, wherein the transmission rate increase unit sets a modulation multilevel number of a modulation scheme used for transmission of the signal to a modulation multilevel number included in the delay notification. A first communication device and a plurality of second communication devices are used to transmit signals between the first communication device and the plurality of second communication devices using a plurality of time slots obtained by dividing a communication time zone. A communication control method in a communication system to perform,
The first communication device receives a signal transmitted by the plurality of second communication devices using the time slot; and
The first communication device measuring a delay time of the received signal;
A delay notification indicating a signal delay when the first communication device exceeds the allowable time, which is the maximum delay time within which the time position of the signal falls within the time slot of the time slot, the measured delay time The second communication device that is the transmission source of the signal whose delay time exceeds the allowable time, and the time next to the time slot used for transmission of the signal whose delay time exceeds the allowable time Transmitting to any of the second communication devices that are sources of signals transmitted using slots;
The first communication device extending a frequency bandwidth used for signal transmission when the measured delay time exceeds the allowable time; and
The second communication device receiving the delay notification from the first communication device;
When the second communication device receives the delay notification, increasing the transmission rate of the signal to be transmitted using the time slot , and
In sending the delayed notification, the first communication device, the delay communication control method that sends a notification including the frequency bandwidth after expansion by the frequency bandwidth extending unit.

Images