JP6953333B2 - Wireless communication methods, wireless communication systems and programs - Google Patents

Description

The present invention relates to a wireless communication method for wireless communication used for mobile control.

In recent years, there has been a movement to utilize wireless communication for controlling mobile objects. For example, in the field of train control, ETCS (European Train Control System) Level 2 or later, CBTC (Communication Based Train Control), and the like are known. Further, in the field of automatic driving of automobiles, V2X (Vehicle to Everything) and the like are known. Communication used for mobile control is required to reduce packet error rate, latency, delay jitter, and the like.

On the other hand, if a new communication infrastructure is developed only for mobile control and a separate communication module is prepared for each communication purpose, the cost will be high. Therefore, within the range allowed by the communication band of the wireless system, other than mobile control A communication infrastructure that can accommodate multipurpose communications is desirable.

In Patent Document 1, an on-board radio station and a terrestrial radio base station mounted on a train are used for the purpose of improving the arrival rate of communication data used for train control between the terrestrial radio base station and the on-board radio station. A train control system that controls train operation by transmitting and receiving information including train control information, which is information that controls train operation, by wireless communication, and train control information transmitted by a terrestrial wireless base station. General transmission information, which is information other than train control information, is transmitted from the terrestrial radio base station to one on-board radio station only once, and train control information is transmitted from the terrestrial radio base station to one on-board radio station. It is repeatedly transmitted to the on-board radio station multiple times, and the on-board radio station is disclosed by the train control system that uses the first train control information received for train operation among the train control information without causing data loss. Has been done.

International Release 2016/129086

Abe et al., "Soft Judgment Decoding Method in Differential PSK Modulation Method", IEEJ Transactions, Vol. 111, No. 11, pp563-568, 1991.

In the method disclosed in Patent Document 1, wireless communication resources are allocated to each train in units of slots in which a half slot of train control information and a half slot of general information are combined, so that an upward direction is applied to some trains. Alternatively, there is a problem that flexible operation for temporarily increasing the transmission capacity of general information in the downlink direction is difficult. In other words, in Patent Document 1, the transmission capacity of general information can be increased by increasing the number of slots allocated to a certain train, and the transmission capacity of train control information is also increased.

A typical example of the invention disclosed in the present application is as follows. That is, it is a wireless communication method in a wireless communication system using a fixed station and a mobile station, and the wireless frame used in the wireless communication method includes at least a control system channel for transmitting information used for mobile control and the mobile. A non-control channel that transmits information other than that used for control, a broadcast channel that notifies all the mobile stations of radio control information, and an access used to establish a connection from the mobile station to the fixed station. Including the control channel, the fixed station allocates at least one uplink and downlink channel pair of the control system channel to the mobile station in the radio frame, and the uplink and downlink communication directions in the non-control system channel. Is dynamically switched to dynamically assign the non-control system channel to the mobile station, and the mobile station assigns to the channel pair assigned to the mobile station when non-control system information to be transmitted occurs. At least one of the included uplink control channels should be used to request the fixed station to allocate the uplink non-control channel, which should receive or transmit the uplink non-control channel allocation request. When non-control system information is generated, the mobile station to which the non-control system channel is assigned and the upstream or downstream communication direction of the non-control system channel are determined, and the result of the determination is used for all the movements of the above-mentioned movement using the broadcast channel. and it features that you notice the station.

According to one aspect of the present invention, it is possible to allocate a large amount of communication band to a specific terminal while continuously providing the mobile control itself. Issues, configurations and effects other than those mentioned above will be clarified by the description of the following examples.

It is a figure which shows the structural example of the system of the Example of this invention. It is a figure which shows the configuration example of the wireless transmission apparatus of this Example. It is a figure which shows the configuration example of the radio channel of this Example. It is a figure which shows the structure inside the radio channel of this Example. It is a figure which shows the example of the data modulation symbol arrangement in the radio channel of this Example. It is a figure which shows the example of the DQPSK modulation of this Example. It is a figure which shows the configuration example of the wireless transmission control arithmetic unit on the fixed radio station side of this embodiment. It is a figure which shows the configuration example of the config information memory of this Example. It is a figure which shows the configuration example of the mobile management memory of this Example. It is a flowchart of the process executed by the access control part of this embodiment. It is a flowchart of the process executed by the scheduler of this embodiment. It is a flowchart of the process executed by the MAC packet processing part of this embodiment. It is a figure which shows the structural example of the MAC data block of the DCCH of this Example. It is a figure which shows the structural example of the data block of SCH of this Example. It is a figure which shows the structural example of the BCH data block of this Example. It is a figure which shows the Example of UCCH of this Example. It is a figure which shows the structural example of ACCH of this Example. It is a figure which shows the configuration example of the wireless signal processing arithmetic unit of this Example. It is a figure which shows the configuration example of the wireless signal transmission / reception device of this Example. It is a figure which shows the configuration example of the wireless transmission control arithmetic unit on the moving body side of this Example. It is a figure which shows the operation sequence at the time of handover.

<Example 1>
FIG. 1 is a diagram showing a configuration example of a system according to an embodiment of the present invention.

The system of this embodiment includes a control information transmission device 11, a non-control information transmission device 12, one or more fixed radio stations 13, and a backbone network 16 as a communication medium between them. A mobile station provided in one or a plurality of mobile bodies 23 is connected to the fixed radio station 13 by wireless communication. The backbone network 16 may be a wired network or a wireless network. Hereinafter, the mobile station that communicates with the fixed radio station 13 will be regarded as the mobile body 23 as a whole, and will be referred to as the mobile body 23.

The control information transmission device 11 is a device that bidirectionally transmits information related to the control of the mobile body 23 to and from the mobile body 23. For example, the control information transmission device 11 has a function of collecting the position information of the moving body 23 from the moving body 23 and notifying the moving body 23 of the range in which the moving body 23 can move.

The non-control information transmission device 12 is a device that bidirectionally transmits information other than the control of the mobile body 23 to and from the mobile body 23. For example, the non-control information transmission device 12 has a function of collecting command information to be transmitted to a person who operates the moving body 23, log information, video information, and the like from the moving body 23.

The control information transmission device 11 and the non-control information transmission device 12 control the communication of the upper layer, and store the IP packet and the packet conforming to the system-specific protocol in the information transmission block of the wireless layer to move the mobile body. Bidirectional communication is performed between the control information transmission device 21 and the non-control information transmission device 22 on the 23 side.

The wireless transmission device 14 and the antenna 15 are components of the fixed wireless station 13, and perform wireless communication between the wireless transmission device 24 and the antenna 25 of the mobile body 23. Details of the wireless communication method will be described later.

FIG. 2 is a diagram showing a configuration example of the wireless transmission devices 14 and 24 of this embodiment.

In this embodiment, the wireless transmission device 14 of the fixed radio station 13 and the wireless transmission device 24 of the mobile body 23 are partially different in operation, but the hardware may have the same configuration.

The network interface device 101 is a device that communicates by wire or wirelessly according to a communication method defined between the control information transmission devices 11 and 21 and the non-control information transmission devices 12 and 22, and is a physical layer used in the communication method. It has a modem function that processes lower layers such as a data link layer, a MAC (Media Access Control) layer, and the like. As the network interface device 101, a chip or board having a general modem function can be used.

The packet buffer 105 is a queue that temporarily stores data transmitted and received by the network interface device 101 to and from the control information transmission devices 11 and 21 and the non-control information transmission devices 12 and 22. The packet buffer 105 may be provided in a volatile memory built in the network interface device 101, or may be provided in a separate volatile memory.

The wireless transmission control arithmetic unit 102 is composed of a memory for storing devices such as a CPU, MPU, and DSP, and a program to be executed. After the wireless transmission devices 14 and 24 are started, the program is written to the memory to realize a necessary function. .. This program is read from the program memory 110 and written through the common bus 109. The program memory 110 is composed of a non-volatile memory.

The boot processing device 111 controls the writing of the program from the program memory 110 to the wireless transmission control arithmetic unit 102. The boot processing device 111 is composed of a non-volatile memory in which a boot control program is written and an MPU that executes a program on the memory. The MPU first executes the boot control program after the wireless transmission devices 14 and 24 are started. Run.

The wireless control memory 107 is composed of a volatile memory, and the wireless transmission control arithmetic unit 102 stores information related to wireless control with the mobile body 23. For example, it is information about the allocation of the radio channel to the mobile body 23, the details of which will be described later.

The wireless transmission buffer 106 is composed of a volatile memory, and is a buffer for passing information transmitted / received by radio between the wireless transmission control arithmetic unit 102 and the wireless signal processing arithmetic unit 103. The wireless transmission buffer 106 enables the wireless transmission control calculation device 102 and the wireless signal processing calculation device 103 to operate asynchronously, but the wireless transmission control calculation device 102 and the wireless signal processing calculation device 103 are realized (for example, by a DSP). In the case of synchronous operation, the wireless transmission buffer 106 can be omitted.

The wireless signal processing arithmetic unit 103 has a function of converting an information bit sequence and a baseband digital signal, and is realized by a DSP, an FPGA, or the like. Details will be described later. The function of the wireless signal processing arithmetic unit 103 may be realized by a program. The program is read from the program memory 110 when the wireless transmission devices 14 and 24 are started by the same procedure as that of the wireless transmission control arithmetic unit 102.

The signal processing memory 108 stores buffers and tables referred to by the wireless signal processing arithmetic unit 103, and even the volatile memory built in the wireless signal processing arithmetic unit 103 (DSP or FPGA) is a separate volatile memory. It may be a memory.

The wireless signal transmitter / receiver 104 has a conversion function between a baseband digital signal and a high-frequency analog signal, and can be used as an A / D (analog-digital) converter, a D / A (digital-analog) converter, a filter, a mixer, an amplifier, and the like. It is a wireless communication module that has. In this embodiment, in order to perform TDD (Time Division Duplex) communication, a switch for switching between transmission and reception is provided on the antenna side. The high frequency analog signal is transmitted and received via the antennas 15 and 25.

FIG. 3 is a diagram showing a configuration example of the radio channel of this embodiment. In the following description, wireless communication transmitted by the mobile body 23 and received by the fixed radio station 13 is defined as uplink communication, and wireless communication transmitted by the fixed radio station 13 and received by the mobile body 23 is defined as downlink communication.

Frames 201 having the same time length are arranged continuously in time. In the frame 201, the broadcast channel 202, the downlink control information transmission channel 203, the uplink control information transmission channel 204, the access control channel 205, and the non-control information sharing transmission channel 206 are arranged in a time division manner. NS. In all frames 201, the channel time division arrangement is the same. The broadcast channel 202 is a channel for transmitting common radio control information from the fixed radio station 13 to all the mobile bodies 23 within the radio coverage of the fixed radio station 13. The downlink mobile control information transmission channel 203 is a channel for transmitting information related to the control of the mobile 23 from the fixed radio station 13 to the mobile 23. The uplink mobile control information transmission channel 204 is a channel for transmitting information related to the control of the mobile 23 from the mobile 23 to the fixed radio station 13. The access control channel 205 is a channel for the mobile unit 23 whose connection with the fixed radio station 13 has not been established to transmit a connection request to the fixed radio station 13. The uncontrolled information sharing transmission channel 206 is a channel for transmitting information other than mobile control between the fixed radio station 13 and the mobile 23, and is shared among a plurality of mobiles 23 to perform uplink communication. It is possible to switch the downlink communication.

Each of the aforementioned channels is further time divided into one or more channels. Further, frequency hopping may be performed so that each time division channel is transmitted at a different frequency. Frequency hopping is not essential for the practice of the present invention, but in communications that require reliability such as control of the mobile 23, a sufficient frequency bandwidth that can be used in the system can be secured, and frequency hopping is applied. It is desirable to obtain the frequency diversity effect. BCH207 is the time-division channel of the broadcast channel 202, DCCH208 is the time-division channel of the downlink control information transmission channel 203, UCCH209 is the time-division channel of the uplink control information transmission channel 204, and ACCH210 is the access control channel 205. The divided channel, SCH211 is a time-division channel of the uncontrolled information sharing transmission channel 206. In this embodiment, four BCH207, four DCCH208, four UCCH209, four ACCH210, and two SCH211 are described in one frame, but these are examples, and each radio channel has one. The present invention can be carried out if there is at least one in the frame.

FIG. 4 is a diagram showing a configuration inside the radio channel of this embodiment.

Each of the time-division channels such as BCH207, DCCH208, UCCH209, ACCH210, and SCH211 shown in FIG. 3 is configured as shown in FIG. A preamble 221 known on the receiving side is arranged at the head of the time division channel. On the receiving side, the preamble 221 can detect the reception timing and frequency shift of the time-division channel.

The data 222 of each channel is arranged behind the preamble 221. The data 222 is generated by adding an error detection code and an error correction coding to the information bit sequence and performing radio signal processing such as modulation. Details of wireless signal processing will be described later. In this embodiment, differential QPSK (DQPSK) is adopted as the primary modulation method, and OFDM is adopted as the secondary modulation method, but the present invention can be realized by other modulation methods as long as each channel is time-division-arranged. be.

A guard section 223 between radio channels, which is a non-transmission section, is arranged at the end. Due to the guard section 223, the reception timing shift caused by the distance between the mobile body 23 and the fixed radio station 13 in the uplink transmission, the switching between the uplink communication and the downlink communication within the frame, and the timing shift between the fixed radio stations 13 Can be absorbed.

As shown in FIG. 4, BCH207, DCCH208, UCCH209 and ACCH210 have the same configuration. By adopting the same configuration for these time division channels, the configuration of the receiver can be simplified. Since the SCH 211 is a channel used for various purposes, a longer time is allocated to the data 222 so that a larger payload can be loaded as compared with the BCH 207 and the like. In the case of the data arrangement shown in (2-1) in the figure, the size of the coded block is larger than that of BCH207 or the like. In cellular systems and the like, various coded block sizes are defined, and a method that efficiently utilizes the transmission capacity of the radio propagation path in combination with adaptive modulation technology is used. This idea has the advantage that the transmission capacity of the radio propagation path can be efficiently utilized, but also has the disadvantage that the transmitter / receiver becomes complicated because it supports various block sizes and modulation methods. Real-time feedback control for adaptive modulation is also complicated.

On the other hand, as shown in (2-2), a plurality of blocks having the same block size as BCH207 or the like may be arranged side by side to form the data unit 222-3. In this case, although it is inferior to the above-mentioned method (2-1) from the viewpoint of efficient utilization of wireless transmission capability, there is an advantage that the receiver can be simplified. In particular, since the system used for controlling the moving body 23 is required to have reliability, the method (2-2) may be preferable to the method (2-1), which requires man-hours for development and testing. In this embodiment, the method (1) is adopted for the channel configuration other than the SCH211 and the method (2-2) is adopted for the channel configuration of the SCH211.

FIG. 5 is a diagram showing an example of data modulation symbol arrangement in the radio channel of this embodiment.

From the viewpoint of simplifying the configuration of the receiver, the number of OFDM symbols is the same for all radio channels such as BCH207 and SCH211. However, when the SCH 211 is configured as shown in (2-1) of FIG. 4, only the SCH 211 has a larger number of OFDM symbols than the BCH 207 or the like. In this embodiment, SCH211 also has the same number of OFDM symbols as other radio channels. In this embodiment, the case where the number of subcarriers is 16 and the number of OFDM symbols is 9 is illustrated, but this number should be determined in consideration of the number of radio channels to be secured, the system bandwidth, the transmission rate required for the application, and the like. Therefore, the present invention can be implemented as long as at least the amount of information to be transmitted by the modulation symbol excluding the reference is secured in each radio channel by the broadcast channel or the like.

On the grid of OFDM symbols and subcarriers, a phase reference symbol 231 for performing differential QPSK modulation, guard subcarriers and DC subcarriers 232, data symbol 233 after differential QPSK modulation, and data symbols 233 from inside and outside the system. A null symbol 234 for observing interference is arranged. No symbol having amplitude is placed in the data symbol 233 and the null symbol 234.

Various methods can be considered for arranging the data symbol 233 and the null symbol 234, but they can be roughly divided into (1) a method of arranging the null symbol 234 in the same subcarrier with different OFDM symbols and (2) for each OFDM symbol. There is a way to place them in different subcarriers. In the method (1), DQPSK modulation is performed with reference to the phase of the OFDM symbol immediately before the same subcarrier, so that DQPSK modulation itself can be simply realized, but narrow-band interference occurring between null symbols 234. Is difficult to observe. In other words, since the receiving side cannot recognize the interference that occurs between the null symbols 234, the estimation accuracy of the likelihood of each bit referred to during demodulation or decoding is lowered, which is a factor that deteriorates the error rate characteristic of the channel. Become. In an environment where such narrow-band interference does not occur, the arrangement of the null symbol 234 as shown in (1) does not pose a problem. On the other hand, in an environment where narrow-band interference can occur, it is better to place the null symbol 234 on different subcarriers as shown in (2).

In this embodiment, one null symbol 234 is placed in each of the three subcarriers, but this is optimized according to the transmission rate required by the application and the bandwidth and duration of the interference to be observed. The value to be done. The more null symbols 234 are arranged, the narrower the band and the shorter the duration of interference can be captured, but the transmission rate that can be secured by the application becomes lower, so this trade-off is taken into consideration when making a decision. When optimizing, it is also considered that interference with a narrow band and short duration can be overcome by an error correction code if the frequency of occurrence is low. That is, the arrangement density of the null symbol 234 is an optimization parameter according to the assumed application and the assumed interference, and if the number of data symbols can secure the amount of information required for transmission on a wireless channel such as BCH207, the null symbol 234 It is possible to carry out the present invention at most. However, when the null symbol 234 is arranged as shown in (2), it is necessary to devise something that was not necessary to consider in (1) when performing DQPSK modulation. This will be described with reference to FIG.

FIG. 6 is a diagram showing an example of DQPSK modulation of this embodiment.

FIG. 6 shows a grid of physical subcarriers and OFDM symbols, but as shown, the logical subcarriers exemplified as 241 in the range excluding the guard subcarrier, the DC subcarrier 232, and the null symbol 234. Is defined. The first OFDM symbol of each logical subcarrier has a phase reference symbol 231 for DQPSK modulation, and thereafter, the previous OFDM symbol and the DQPSK modulation symbol based on the phase of the same logical subcarrier are arranged. The phase reference symbol and the first DQPSK modulation symbol in the same logical subcarrier are selected to be the same physical subcarrier. This is because it is desirable that the propagation path response between the symbol to be modulated and the symbol that serves as the phase reference of the symbol when performing differential modulation has a high correlation, so that the symbols are as close as possible on the time or frequency axis. It can be expected that differential modulation will be performed depending on the combination.

FIG. 7 is a diagram showing a configuration example of the wireless transmission control arithmetic unit 102 on the fixed radio station 13 side of this embodiment.

The packet buffer 105 provided between the network interface device 101 and the network interface device 101 is composed of a control information buffer 301 and a non-control information buffer 302. The control information buffer 301 is a buffer that temporarily stores packets transmitted to and from the control information transmission device 11, and the non-control information buffer 302 is a packet transmitted to and from the non-control information transmission device 12. Is a buffer that temporarily stores. In the case of uplink communication, when the transmission packet is stored, it is transferred by the network interface device 101 to the control information transmission device 11 and the non-control information transmission device 12. In the case of downlink communication, packets stay in the packet buffer 105 until the wireless communication channel is assigned by the scheduler 305. The packets stored in the control information buffer 301 are transmitted by the radio channels DCCH 208 and UCCH 209, and the packets stored in the non-control information buffer 302 are transmitted by the SCH 211.

The wireless control memory 107 includes a config information memory 303 (see FIG. 8) and a mobile management memory 304 (see FIG. 9). The config information memory 303 is a memory that is a setting parameter unique to the fixed radio station 13 and stores parameters necessary for communicating with the mobile body 23 connected to the fixed radio station 13. be. For example, it is a parameter related to frequency hopping and a parameter related to the rule of the null symbol arrangement method. The contents of the config information memory 303 are notified to the mobile body 23 by the BCH 207. The mobile management memory 304 is a memory that manages the identifier of the mobile 23 connected to the fixed radio station 13, the radio channel assigned to each mobile 23, and the retransmission state of non-control information. When the mobile body 23 establishes a connection with the fixed radio station 13, a storage area for the mobile body is secured in the mobile body management memory 304. When the mobile 23 implicitly or explicitly disconnects from the fixed radio station 13, the storage area of the mobile 23 is deleted from the mobile management memory 304.

The scheduler 305 allocates a mobile unit 23 for packet transmission in uplink and downlink communication on each of the DCCH 208, UCCH 209, and SCH 211 radio channels in the frame. Further, the scheduler 305 reads the config information transmitted by the BCH 207, manages the frame number, notifies the MAC packet processing unit 306 of the frame number, and specifies a mobile identifier that can be used for each of the ACCH 210. The scheduler 305 notifies the MAC packet processing unit 306 of the result of the above-mentioned allocation in order to notify the mobile body 23 by the BCH 207. In this embodiment, DCCH208, UCCH209, BCH207 and ACCH210 are not supposed to be retransmitted in the radio layer, but SCH211 performs ARQ retransmission. Retransmission of the SCH 211 is managed in the mobile management memory 304, and the scheduler 305 refers to the mobile management memory 304, and if there is a SCH 211 that needs to be retransmitted, the allocation priority of the SCH 211 that needs to be retransmitted. Raise. However, as the config information for each fixed radio station 13, it is advisable to set an upper limit on the number of retransmissions.

The MAC packet processing unit 306 has a processing on the transmitting side and a processing on the receiving side.

As the processing on the transmitting side of the MAC packet processing unit 306, a sequence number, which is a serial number of the packet, is generated for each radio channel for each mobile unit. In the retransmission packet of SCH211, the sequence number of the packet to be retransmission is assigned. The generated sequence number is added to the beginning of data such as the control information buffer 301 as header information, and is written to the control channel buffer 308 or the like. The BCH 207 acquires the config information, the frame number, and the radio channel allocation information from the config information memory 303 and the scheduler 305, and generates a data block. A MAC header containing the sequence number is added to the beginning of the data block. When requesting the retransmission of the uplink SCH211, information indicating the packet to be retransmitted is added to the MAC header of the DCCH208. Which uplink SCH211 is to be retransmitted refers to the reception result of the uplink SCH211 recorded in the non-control channel buffer 309. This operation is related to the processing on the receiving side, which will be described later.

As processing on the receiving side of the MAC packet processing unit 306, received data is acquired from each channel buffer (control channel buffer 308, non-control channel buffer 309, broadcast channel buffer 310), and the MAC header is analyzed. When the sequence number overlaps with the data received in the past, the received packet is discarded if the received data is other than SCH211 or the sequence number is not to be retransmitted by SCH211, that is, the sequence number has already been successfully received. When the SCH211 is to be retransmitted, it is combined with the result received in the past, and the data is written to the non-control information buffer 302 after all the data are collected. When some data is not available, the received data is retained in the non-control channel buffer 309, and the range requiring retransmission (retransmission target of the uplink SCH211) is stored in the mobile management memory 304. Even if the sequence number is missing, the range that needs to be retransmitted is stored in the mobile management memory 304. When the SCH211 is the target of retransmission and the number of retransmissions reaches the upper limit, the data stored in the non-control channel buffer 309 is discarded. In the case of the received data of the ACCH 210, the received packet is transferred to the access control unit 307 as it is. The MAC header of the UCCH 209 may store a retransmission request for the downlink SCH 211, and when the MAC packet processing unit 306 confirms the retransmission request, the information in the mobile management memory 304 is updated.

The access control unit 307 manages the number of mobile bodies 23 connected to the fixed radio station 13. When the mobile body management memory 304 is referred to by the input of the ACCH 210 as a trigger, the mobile body 23 has no record in the mobile body management memory 304, and the upper limit of the number of mobile bodies 23 that can be connected to the fixed radio station 13 is not exceeded. , The moving body 23 is added to the moving body management memory 304. However, if the access is from a mobile body other than the mobile unit 23 permitted by the scheduler 305, the ACCH 210 is discarded. Although related to the handover described later, the mobile 23 that moves from the fixed radio station 13 to another fixed radio station 13 is deleted from the mobile management memory 304. The implicit deletion from the mobile management memory 304 when the communication on the mobile side is interrupted is determined by the MAC packet processing unit 306 based on the comparison result between the number of continuous reception failures of the UCCH 209 and a predetermined threshold value.

FIG. 8 is a diagram showing a configuration example of the config information memory 303 of this embodiment.

The config information memory 303 stores as a config value the contents to be notified in common to all the mobile bodies 23 that are connected to or are about to be connected to the fixed radio station 13. The config information memory 303 The stored config value is transmitted to the mobile body 23 on the broadcast channel (BCH) 207 of each frame. The contents stored in the config information memory 303 are the identifier 3031 of the fixed radio station 13, the rule of the null symbol placement method (subcarrier offset value of the null symbol placement) 3032, and the frequency hopping rule (frequency hopping interval 3033 and frequency). The offset value 3034) of the frequency channel that is the base point of hopping is included.

The subcarrier offset value of the null symbol arrangement is, for example, the null symbol arrangement shown in FIG. 6 is set to the subcarrier offset value 0, the null symbol is shifted upward by one subcarrier as a whole, and the null symbol overflows upward. The arrangement that wraps around to the lower side is a config value for shifting the arrangement of null symbols between the fixed radio stations 13, such as a subcarrier offset value 1. By arranging the null symbols in this way, mutual interference between the fixed radio stations 13 having the same frequency hopping pattern can be measured by using the null symbols.

Frequency hopping will be described using mathematical formulas.

When L frequency channels can be arranged in the entire wireless system, the frequency channel F applied to a certain wireless channel can be calculated by the following equation.

Here, frame is a frame number generated by the scheduler 305, and offset and step are a frequency hopping offset and a frequency hopping step, which are config values, respectively. Further, i is a serial number of the radio channel in the frame. For example, in the example shown in FIG. 3, 0 to 3 for BCH # 0 to # 3, 4 to 7 for DCCH # 0 to # 3, and UCCH # 0 to # 8 to 11 are assigned to 3, 12 to 15 are assigned to ACCH # 0 to # 3, and 16 to 18 are assigned to SCH # 0 to # 2. mod5 refers to a modulo operation, which is an operation for obtaining a remainder obtained by dividing an argument by 5.

FIG. 9 is a diagram showing a configuration example of the mobile management memory 304 of this embodiment.

The mobile body management table 304A shown in FIG. 9A is a table that manages each of the mobile bodies connected to the fixed radio station 13.

The mobile identifier 3041 stores the value transmitted by the mobile 23 as it is on the access control channel (ACCH) 210. The control channel allocation cycle 3042 and the control channel allocation offset 3043 make other movements in consideration of the control channel allocation status to the already connected mobile 23 when the mobile 23 establishes a connection on the access control channel 210. It is a value determined by the access control unit 307 so as not to overlap with the body 23. In the example shown in FIG. 3, four pairs of the downlink control channel (DCCH) 208 and the uplink control channel (UCCH) 209 are provided in the frame, and the channel allocation cycle is 8 in this system, so 2 frames. A control channel is assigned to the moving body 23 once every time. The frame number is frame, the serial number of the control channel pair in the frame is n (corresponding to DCCH # n and UCCH # n), the number of control channel pairs in the frame is M, the channel allocation cycle is K, and the moving body is assigned. Assuming that the control channel allocation offset is offset, the control channel pair that can be used by the moving body 23 satisfies the following formula.

The downlink non-control information untransmitted data amount 3044 is the untransmitted data amount related to the moving body 23 stored in the non-control information buffer 302. The amount of untransmitted downlink uncontrolled information increases due to the generation of downlink uncontrolled information, and when a retransmission request does not occur after transmission to the mobile 23, that is, when transmission to the mobile 23 is successful, the fixed radio station It decreases when 13 is determined.

The upstream non-control information untransmitted data amount 3045 is the untransmitted non-control information data amount held by the moving body 23. Each time the amount of uncontrolled information data transmitted from the mobile body 23 is received in the UCCH 209, the value is updated to the latest value, and the amount of uncontrolled information data transmitted from the mobile body 23 by the SCH 211 is reduced.

The final sequence number 3046 for which the downlink non-control information has been transmitted is the total number of data blocks of the non-control information transmitted to the moving body 23. This number does not change when a retransmission request is received for a transmitted data block. In the case of the configuration (2-2) of FIG. 4, the blocks separated by the broken lines are regarded as one data block. That is, when the non-control information is transmitted in the configuration of (2-2) of FIG. 4, this number is incremented by 3.

The downlink non-control information retransmission request sequence number list 3047 is added when the moving body 23 notifies the sequence number requiring retransmission through the UCCH 209. When the non-control information of the sequence number to be retransmitted is transmitted by the SCH 211 and it is confirmed that the retransmission request does not occur from the mobile body 23, the sequence number is deleted from the downlink non-control information retransmission request sequence number list 3047. ..

The uplink non-control information received final sequence number 3048 is a value of the final sequence number included in the MAC header transmitted from the mobile body 23 by the SCH 211. That is, the final sequence number 3048 for which the uplink non-control information has been received is updated by copying the value of the final sequence number managed by the mobile body 23 itself.

In the uplink non-control information retransmission request sequence number list 3049, a sequence number corresponding to the data block that failed to be received is added to the data block transmitted from the mobile body 23 on the SCH 211. When the reception is successful due to the retransmission of the data block that failed to be received, the sequence number is deleted from the uplink non-control information retransmission request sequence number list 3049.

The uplink control information continuous reception failure count 3050 records the number of consecutive failures in receiving the UCCH 209 of the mobile body 23. As described in the explanation of FIG. 7, when the communication on the mobile body 23 side is interrupted by the determination using the threshold value of this number of times, the mobile body 23 is implicitly deleted from the mobile body management memory 304.

The ACCH management table 304B shown in FIG. 9B is a table for managing the access control channel (ACCH) 210, the scheduler 305 sets the table value, and the access control unit 307 refers to the table. The ACCH management table 304B records the identifier of the mobile 23 that can use each ACCH 210 in the frame. Some of the values of all mobile identifiers are defined as reserved values for all mobiles accessible and all mobiles inaccessible. For example, 0x0000 may be inaccessible to all mobiles, and 0xFFFF may be accessible to all mobiles. The value of inaccessible to all mobiles is used when the number of mobiles 23 connected to the fixed radio station 13 has reached the limit. The value of access to all mobiles is used at normal times, except when a resource is reserved for a specific mobile 23 by handover.

FIG. 10 is a flowchart of a process executed by the access control unit 307 of this embodiment.

When the access control unit 307 is activated, it waits for the ACCH210 input from the MAC packet processing unit 306 in step 1001. When the input of the ACCH 210 is confirmed, the ACCH management table 304B shown in FIG. 9B is referred to in step 1002, the number of the ACCH 210 is collated with the mobile identifier included in the ACCH 210, and the mobile identifier is the ACCH 210. Determine if access is permitted at. If access is permitted, it is confirmed in step 1003 whether the mobile management table 304A shown in FIG. 9A is already secured for the mobile 23.

If the mobile management table 304A has already been secured, the secured mobile management table 304A is reused. The mobile management table 304A is secured during the reconnection operation after the temporary communication disconnection. If the mobile management table 304A is not secured, the mobile 23 connected to the fixed radio station 13 is assigned an access control channel (ACCH) 210 that has not yet been used in step 1004, and the mobile 23 is assigned. Create a new storage area for. At the time of new connection including handover, the mobile management table 304A is not secured, and the mobile management table 304A is newly secured.

FIG. 11 is a flowchart of processing executed by the scheduler 305 of this embodiment.

When the scheduler 305 is started, the wireless channel allocation process is started every frame cycle (for example, 100 ms) in step 1011 based on the time managed by the hardware of the wireless transmission control arithmetic unit 102. When the allocation process is started, 1 is first added to the frame number in step 1012.

Next, in step 1013, referring to the mobile management table 304A and the frame number shown in FIG. 9 (A), the identifiers of the mobile 23 to which DCCH208 and UCCH209 are assigned are assigned in the order of channel pair numbers, as many as the number of channel pairs in the frame. assign. The channel pair number N corresponds to a pair of DCCH # N and UCCH # N. When the number of mobile bodies 23 connected to the fixed radio station 13 is small and there is no mobile body 23 to be assigned, for example, 0x0000 may be assigned as the mobile body identifier. This number may be matched with the reserved mobile identifier inaccessible to all mobiles shown in the ACCH management table 304B shown in FIG. 9B to prohibit access to the channel from the mobile 23.

Next, in step 1014, SCH211 is assigned. Various methods are known for dynamic scheduling, but here we consider the simplest round robin. As an example, assume a token that first makes a round of the mobile identifier in the downlink communication, then makes a round of the mobile identifier in the uplink communication, and repeats the operation of returning to the downlink communication again. With respect to the communication direction in which the token has come around and the mobile identifier, the presence / absence of untransmitted data and the presence / absence of retransmission data are determined with reference to the mobile management table 304A shown in FIG. 9 (A). If there is data to be transmitted (untransmitted data, retransmission data), the data is searched in order from SCH # 0, and if there is a free channel, SCH211 in the communication direction is assigned to the mobile unit 23. When the data presence / absence determination and the allocation of the SCH 211 are completed, the token is passed to the next mobile 23. The above processing is repeated until all SCH211 are assigned or there is no uncontrolled information to be transmitted by SCH211. If there is an unallocated SCH211 after one round of tokens, a 0x0000 mobile identifier is assigned to the unallocated SCH211. The token position after the completion of frame scheduling is the initial value at the time of frame scheduling operation in the next frame. The token position at startup can be anywhere.

Next, in step 1015, ACCH 210 is assigned. First, when the number of mobiles 23 connected to the fixed radio station 13 has reached the upper limit, that is, when there is no capacity to allocate a control channel, a mobile identifier indicating that all mobiles 23 are inaccessible. Allocate 0x0000 to all ACCH210s and end the allocation. In other cases, the mobile identifier 0xFFFF indicating that all mobiles 23 are accessible is assigned to all ACCH 210s, and the connection is scheduled by handover from the mobile 23 connected to the other fixed radio station 13. Check for presence. If there is a connection plan, the mobile identifier is assigned to any of ACCH210. The mobile identifier may be overwritten on the ACCH 210 initialized with 0xFFFF in ascending order of the ACCH 210 numbers.

Next, in step 1016, the allocation result of DCCH208, UCCH209, SCH211 and ACCH210, that is, a list in which the radio channel and the mobile identifier are associated one-to-one is output to the MAC packet processing unit 306.

FIG. 12 is a flowchart of processing executed by the MAC packet processing unit 306 of this embodiment.

The MAC packet processing unit 306 has a function of generating a downlink packet and outputting it to the wireless signal processing arithmetic unit 103, and a function of analyzing the uplink packet received by the wireless signal processing arithmetic unit 103 and updating the contents of various buffers and memories. There is.

The downlink packet generation process is started when the notification of the completion of radio channel allocation by the scheduler 305 is received in step 1021 in the form of interprocess communication, interthread communication, or function call. Subsequent processing does not affect the feasibility of the present invention even if the order of execution is changed.

First, in step 1022, all the data blocks of DCCH 208 are generated from DCCH # 0 to DCCH # N-1 in the order of channel numbers.

FIG. 13 is a diagram showing a configuration example of a MAC data block of DCCH208 of this embodiment.

The MAC data block of DCCH208 is composed of a MAC header 2001 and a data body 2002. The data body 2002 refers to the mobile identifier of the allocation target received from the scheduler 305 with respect to DCCH # n, and reads out a bit string from the control information buffer 301 related to the mobile identifier by the amount of data that can be transmitted by the physical layer of DCCH 208. If the length of the read bit string is less than the amount of data that can be transmitted in the physical layer of DCCH208, the read data is padded and additional bits are added after it. Therefore, the number of valid data block bytes excluding padding is stored in the MAC header 2001.

At the time of the first transmission to the moving body 23, the downlink control information sequence number is set to 0, and is incremented by 1 each time a different data block is transmitted. When the same data block is transmitted multiple times, the sequence number is not updated. The uplink non-control information final sequence number indicates the final sequence number transmitted from the mobile body 23 on the SCH 211, and refers to the downlink non-control information transmitted final sequence number 3046 of the mobile body management table 304A shown in FIG. 9 (A). do. The uplink non-control information retransmission request bitmap is a bitmap showing a retransmission request of a data block whose sequence number is traced back by s based on the non-control information final sequence number. Here, the most significant bit of the bitmap points to the uplink non-control information final sequence number itself, that is, s = 0, the second upper bit corresponds to the sequence number of s = 1, and the bit value is 1. The number is requested to be resent. This retransmission request sequence number is generated based on the uplink non-control information received final sequence number 3048 and the uplink non-control information retransmission request sequence number list 3049 in the mobile management table 304A shown in FIG. 9A.

When the mobile identifier to be assigned in a certain DCCH # n is 0x0000, instead of generating a MAC data block and inputting it to the radio signal processing arithmetic unit 103, a Disbrer for not generating a radio signal in the DCCH 208 is used. It may be input to the wireless signal processing calculation device 103.

When the MAC packet processing unit 306 finishes generating the data block of DCCH 208, the MAC packet processing unit 306 then generates the data block of SCH 211 in step 1023. If SCH # n has no downlink communication, this step is skipped for SCH # n. When SCH # n is downlink communication, the data block of SCH211 shown in FIG. 14 is generated.

FIG. 14 is a diagram showing a configuration example of a data block of SCH211 of this embodiment.

The data block of SCH211 includes a MAC header 2003 for SCH211 and a data body 2005. The data body reads a bit string from the uncontrolled information buffer 302 by the amount of data that can be transmitted by the SCH211 of the physical layer, but there is a possibility that it does not match the delimiter in the upper layer such as an IP packet. Therefore, the MAC header for SCH211 needs information indicating how many IP packets are partially or wholly contained in the data block of SCH211. Specifically, the MAC header for SCH211 contains information indicating the number of segments, which is the number of IP packets, the byte position at the end of the segment with 0 immediately after the MAC header, and which part of the IP packet is included. Include in. For example, the information indicating which part of the IP packet is included includes whether each segment contains only the beginning of the IP packet (bit flag 0b10), only the end (bit flag 0b01), and the beginning and end. (Bit flag 0b11) or not including the beginning and the end (bit flag 0b00).

When such segmentation is performed, the number of segments becomes indefinite, so that the length of the MAC header also becomes variable. Therefore, the length information of the MAC header itself is also included in the MAC header.

The effective data block size is the size of the MAC header and the data body, which does not include padding, like DCCH208. The padding is generated to fill the difference when the amount of data existing in the non-control information buffer 302 is smaller than the amount of data that can be transmitted by the physical layer SCH211.

The downlink non-control information final sequence number is the last sequence number of the serial numbers of one data block transmitted in (2-1) of FIG. 4 or a plurality of data blocks transmitted in (2-2). Set. The downlink non-control information final sequence number is assigned 0 to the data block transmitted to the moving body 23 for the first time, and then increments by 1 each time a data block occurs.

The downlink non-control information sequence number bitmap is not necessary when a single data block as shown in (2-1) of FIG. 4 is sent by SCH211. However, a plurality of data blocks are sent to SCH211 as shown in (2-2). When sending with, indicates how many data blocks of the sequence number before the final sequence number of the downlink non-control information are to be transmitted. The most significant bit corresponds to the final sequence number, the second high-order bit corresponds to the sequence number immediately before the final sequence number, and the bits correspond to the sequence number in the same manner.

In this method, the sequence numbers transmitted by a plurality of data blocks can be known, but the position of each sequence number in the data blocks cannot be known. Therefore, a data block having a young sequence number is arranged in a data block close to the MAC header, and a data block is arranged so that the sequence number becomes larger as the distance from the MAC header increases.

When determining the data block to be transmitted, with reference to the mobile management table 304A shown in FIG. 9A, priority is given to the retransmission of the data block having the sequence number numbered in the downlink non-control information retransmission request sequence number list 3047. do. If there is no data block to be retransmitted, a new data block is generated for the number of data blocks of SCH211 from the sequence number next to the final sequence number 3046 for which the downlink non-control information has been transmitted in the mobile management table 304A. At this time, the retransmission data block and the non-retransmission data block may be mixed. For example, in the case of (2-2) of FIG. 4, three data blocks are in the SCH 211, the retransmission data block is arranged in the first data block, and the non-retransmission data block is arranged in the remaining two. The receiving side can identify whether each data block is to be retransmitted by the downlink non-control information final sequence number and the downlink non-control information sequence number bitmap in the MAC header.

When the MAC packet processing unit 306 finishes generating the SCH211 data block, the MAC packet processing unit 306 then generates the data block of the BCH207 in step 1024. One data block of BCH 207 is generated, and one generated data block is transmitted by all BCH 207 in the frame.

FIG. 15 is a diagram showing a configuration example of a data block of BCH 207 of this embodiment.

The data block of BCH 207 includes a MAC header 2006 for BCH 207 and a data body 2007. The MAC header includes a MAC header excluding padding, the number of valid data block bytes indicating the length of a valid data block, and a downlink notification information sequence number in which 1 is added each time the BCH 207 is updated, as in the case of SCH211. .. Since all BCH 207s in the frame transmit the same data block, the downlink notification information sequence number is incremented by 1 each time the frame is updated.

The data body of the BCH 207 is stored in the config information memory 303 for a fixed radio station identifier, a null symbol offset value, a frequency hopping interval, a frequency hopping offset, a frame number output from the scheduler 305, and each radio channel in the frame. Contains a list of assigned mobile identifiers.

The DCCH / UCCH # n mobile identifier is an identifier of the mobile 23 to which the channel pair of DCCH # n and UCCH # n in the frame is assigned. The SCH # m mobile identifier is a combination of the identifier of the mobile 23 to which the SCH # m is assigned in the frame and the communication direction (UL; up, Uplink, or DL; down, Downlink). The ACCH # k mobile identifier is an identifier of the mobile 23 that can be accessed using ACCH # k.

The DCCH 208 data block generated above is written to the control channel buffer 308, the SCH 211 data block is written to the non-control channel buffer 309, and the BCH 207 data block is written to the broadcast channel buffer 310. The data block overwritten in the channel buffer is read by the wireless signal processing arithmetic unit 103 side at its own timing to generate a wireless channel.

Next, the processes of steps 1025 to 1028 of FIG. 12 will be described. In steps 1025 to 1028, the processing is started when the decoding processing of all the uplink radio channels is completed on the radio signal processing arithmetic unit 103 side. Completion of the decoding process is a flag written by the wireless signal processing arithmetic unit 103 in the transmission of an interrupt signal from the wireless signal processing arithmetic apparatus 103 to the wireless transmission control arithmetic apparatus 102 and the notification register provided in the buffer between the two. When (for example, 1) is detected by the wireless transmission control arithmetic device 102 (step 1025), the wireless transmission control arithmetic device 102 writes 0 to this register, and the control channel buffer 308, the non-control channel buffer 309, the broadcast channel buffer 310, and so on. The decoding result of each uplink radio channel is acquired from the access control channel buffer 311. The obtained decryption result includes a MAC header, a valid data block, padding, and an indicator indicating success or failure of decryption.

When the MAC packet processing unit 306 receives the notification of the completion of the decoding process of the uplink radio channel from the wireless signal processing arithmetic unit 103, the MAC packet processing unit 306 receives the reception process of the UCCH 209 in step 1026, and if the uplink SCH 211 is in the frame in step 1027, the MAC packet processing unit 306 of the SCH 211 The reception process and the reception process of the ACCH 210 are sequentially performed in step 1028.

The configuration of the UCCH 209 is similar to that of the DCCH 208 shown in FIG. 13, but includes the amount of data remaining in the uncontrolled information buffer 302 held by the moving body 23.

FIG. 16 is a diagram showing an embodiment of UCCH209 of this embodiment.

In the control channel buffer 308, the MAC data block of the UCCH 209 after decoding and the error detection result regarding the MAC data block are recorded for each UCCH 209.

The retransmission request of the downlink SCH211 through UCCH209 is the same as that in the case of passing through DCCH208. If there is a data block that needs to be retransmitted from the downlink non-control information final sequence number and the downlink non-control information retransmission request bitmap in the MAC header, the downlink non-control information retransmission of the moving body management table 304A shown in FIG. The request sequence number list 3047 is updated. The downlink non-control information transmitted final sequence number 3046 of the mobile management table 304A shown in FIG. 9A is updated with the value of the downlink non-control information final sequence number in the MAC header 2008 of FIG.

The error detection result for each DCCH 208 is referred to, and if there is no error, the MAC data block excluding the MAC header and padding is written to the control information buffer 301, and the uplink control information continuation of the moving body management table 304A shown in FIG. 9 (A) is written. Reset the number of reception failures 3050 to 0. If there is an error, the MAC data block is not written to the control information buffer, and 1 is added to the number of uplink control information continuous reception failure times 3050.

When the processing of UCCH209 is completed, the reception processing of the uplink SCH211 is executed next. The configuration of the upstream SCH211 is the same as that in FIG. However, the downlink non-control information final sequence number and the downlink non-control information sequence number bitmap in FIG. 14 are the uplink non-control information final sequence number and the uplink non-control information sequence number bitmap, respectively.

The non-control channel buffer 309 records the MAC data block of the uplink SCH211 after decoding and the error detection result regarding the MAC data block for each of the plurality of MAC data blocks in the uplink SCH211 channel and the uplink SCH211.

First, from the uplink non-control information final sequence number and uplink non-control information sequence number bitmap in the MAC header 2003, and the error detection result for each MAC data block, the uplink non-control information received final sequence number and uplink non-uplink in FIG. The control information retransmission request sequence number list is updated.

Next, assemble the segments for the MAC data blocks where no errors were detected. Among the MAC data blocks stored in the non-control channel buffer 309, those that can be combined from the beginning to the end of the segment using the MAC data block whose error detection result = no detection are sent to the non-control information buffer 302. When all the segments in the write and MAC data blocks have already been written to the non-control information buffer 302, the MAC data block is deleted from the non-control channel buffer 309.

When the processing of SCH211 is completed, the reception processing of ACCH210 is executed next.

FIG. 17 is a diagram showing a configuration example of the ACCH 210 of this embodiment.

ACCH 210 includes ACCH data body 2010. In this embodiment, at a minimum, the source mobile identifier may be transmitted to the fixed radio station 13 via the ACCH 210. In actual operation, the ACCH 210 may include information related to mobile authentication from the viewpoint of ensuring security.

The access control channel buffer 311 records the MAC data block of the ACCH 210 after decoding and the error detection result regarding the MAC data block for each ACCH 210. The ACCH 210 having no error detection result is directly transferred to the access control unit 307. If there is an error, do nothing in particular.

FIG. 18 is a diagram showing a configuration example of the wireless signal processing arithmetic unit 103 of this embodiment.

In this embodiment, the wireless channels used for uplink communication and downlink communication are complementary, but all the data blocks handled are fixed because they have the same coding rate, interleave pattern, modulation method, and number of modulation symbols. The radio station 13 and the mobile body 23 need only have the same radio signal processing calculation device 103, and the portion of the radio transmission buffer 106 to be referred to differs only depending on the radio channel to be handled.

The wireless signal processing arithmetic unit 103 has processing units 401 to 409 on the transmitting side, which will be described below. The data blocks constituting the wireless channel are processed in the order of the wireless channels shown in FIG.

The error detection code unit 401 reads the MAC data block written in the wireless transmission buffer 106 by the wireless transmission control arithmetic unit 102, and adds an error detection code to the end. For example, as the error detection code, a CRC (Cyclic Redundancy Check) code may be used.

The error correction coding unit 402 generates a redundant bit sequence for error correction on the receiving side. For example, convolutional coding may be used.

The interleaved repetition scrambler unit 403 repeats the output of the error correction coding unit 402 so that the number of bits is twice the number of DQPSK modulation symbols in the data block. The bit string after repetition is rearranged by using the interleave pattern stored in advance in the signal processing memory 108 at the same timing as the program writing. The interleaved pattern may be arbitrary, but it is desirable that the sorting be random. The output after interleaving and the pseudo-random number bit string are scrambled by the exclusive OR of each bit. The pseudo-random number bit string is stored in the signal processing memory 108 in advance as in the interleave pattern.

The DQPSK modulation unit 404 pairs the scrambled bit strings by 2 bits, and inputs π / 4 when they are input in the order of 0,0, and 3π / 4, 1,1 when they are input as 1,0. If it is entered, 5π / 4 is assigned, and if 0,1 is input, a phase delta value of 7π / 4 is assigned. As shown in FIG. 6, the immediately preceding OFDM symbol in the same logical subcarrier is used as the phase reference, and the result of modulo calculation of 2π by adding the phase delta value to the phase reference is used as the phase of the logical subcarrier and the OFDM symbol. Further, this is redefined as a phase reference, and the phase of the next OFDM symbol in the same logical subcarrier is repeatedly determined.

The resource mapping unit 405 arranges the DQPSK modulation result, the null symbol, and the differential QPSK phase reference symbol as shown in FIG. For the arrangement of the null symbols, the value of the null symbol arrangement offset in FIG. 8 and the pattern that does not conflict with each other are stored in the signal processing memory 108 in advance. Similarly, for the differential QPSK phase reference symbol for each subcarrier, a pattern common to the entire system is stored in the signal processing memory 108 in advance.

The IFFT unit 406 executes IFFT processing on the output of the resource mapping unit for each OFDM symbol.

The CP addition unit 407 generates a Cyclic Prefix from the output of the IFFT unit 406 and adds it to the front of the IFFT output. For example, when the IFFT output is 64 samples and the CP length is 16 samples, the final 16 samples of the IFFT output are taken out as the CP, and a total of 80 samples are generated and output in the order of CP and IFFT output.

As shown in FIG. 4, the time multiplexing unit 408 time-multiplexes the preamble, the data body, and the guard time. The preamble is stored in the signal processing memory 108 in advance. The data body is the output of the CP addition unit 407.

The frequency shift unit 409 is a block for realizing frequency hopping, and performs a phase shift on the output of the time multiplex unit according to the frequency channel determination method described in the description of FIG. The offset and step for determining the frequency channel are the frequency hopping offset and the frequency hopping interval shown in FIG. 8, and are set by writing from the wireless transmission control arithmetic unit 102 to the register of the wireless signal processing arithmetic unit 103. Similarly, frame writes the value determined by the scheduler 305 to the register of the radio signal processing arithmetic unit 103. Since L is a system default value, it may be recorded in the signal processing memory 108 in advance and referred to by the program, or may be incorporated into the program itself. As described in the description of FIG. 8, i is a value assigned to each radio channel, and it is preferable to incorporate the conversion formula between the radio channel and i into the program itself. The output of the frequency shift unit 409 is input to the wireless signal transmission / reception device 104.

The wireless signal processing arithmetic unit 103 has processing units 410 to 418 on the receiving side, which will be described below. Similar to the transmitting side, data blocks are input from the wireless signal transmitting / receiving device 104 in the order of the wireless channels shown in FIG. 3, and processing is executed for each data block constituting the wireless channel.

The frequency shift unit 410 has the same logic as the frequency shift unit 409 on the transmission side, but performs a phase shift opposite to that on the transmission side.

The preamble detection unit 411 detects the reception timing of the preamble by a matched filter or the like.

Based on the preamble timing of the radio channel detected by the preamble detection unit 411, the FFT unit 412 performs FFT processing on a fixed number of samples corresponding to the number of physical subcarriers immediately after the CP of each OFDM symbol of the data body. , Acquire the frequency domain received signal.

The interference noise power estimation unit 413 estimates the interference noise power of each OFDM symbol and each subcarrier based on the null symbol pattern in the signal processing memory 108 which is also referred to on the transmitting side. The interference noise power E of the OFDM symbol #ofdm and the subcarrier #sc can be estimated by, for example, the following averaging.

N (ofdm, sc) is the interference noise power observed in the OFDM symbol and subcarrier, and is the sum of squares of the complex I component and the real Q component. α (ofdm, sc) is a function indicating whether it is a null symbol, and outputs 1 if it is a null symbol and 0 if it is not a null symbol. a is a value for determining the range to be averaged, and may be arbitrarily determined.

The demodulation processing unit 414 obtains the likelihood for each bit. As a method for obtaining the bit-by-bit likelihood for differential PSK modulation, for example, the method disclosed in Non-Patent Document 1 can be adopted.

The deinterleaved scrambler unit 415 first scrambles the output of the demodulation processing unit 414. The same pseudo-random number sequence as the sender is used, but the likelihood is not a bool value but a continuous value, so if the pseudo-random number sequence is 0, multiply the likelihood by +1. If the pseudo-random number sequence is 1, then -1. Multiply the likelihood. After that, deinterleave is performed by referring to the interleave pattern used on the transmitting side as well.

The likelihood synthesis unit 416 is a process of synthesizing data transmitted a plurality of times as a repetition and the same data block at a likelihood level. At the time of synthesis, the likelihood is divided by the noise power estimated by the interference noise power estimation unit 413 to perform weighted synthesis of the likelihood according to the interference noise power. The targets of synthesis between data blocks are all BCH 207 in the same frame, each DCCH 208 transmitted in R frame continuous transmission, and each UCCH 209 transmitted in R frame continuous transmission.

Under the condition that DCCH208 and UCCH209 have all frames allocated to each moving body 23, when R = 4, the first transmission is when the remainder after dividing frame by 4 is 0, and the same data block is transmitted for 4 consecutive frames from that frame. If it is decided to send, for DCCH208 and UCCH209, four consecutive frames will be the target of synthesis between data blocks. Here, the timings for R and the first transmission are recorded in advance in the signal processing memory 108, and the same settings are set between the fixed radio station 13 and the mobile body 23.

The error correction / decoding unit 417 performs error correction / decoding based on the likelihood of each bit output from the likelihood synthesis unit, determines the decoding result hard, and outputs a bit string of 0 or 1. As the error correction algorithm, for example, the Viterbi decoding method may be used.

The error detection unit 418 performs a CRC check on the input bit string, determines the presence or absence of an error, and transfers the determination result and the bit sequence obtained by removing the CRC from the input bit sequence to the appropriate wireless channel in the wireless transmission buffer 106. Write in the part.

FIG. 19 is a diagram showing a configuration example of the wireless signal transmission / reception device 104 of this embodiment.

In FIG. 19, the upper side is the transmitting side, and provides a function of converting a baseband digital signal output from the wireless signal processing arithmetic unit 103 into a high-frequency analog signal. On the other hand, the lower side is the receiving side, which provides a function of converting a high-frequency analog signal input from the antenna into a baseband digital signal.

In this embodiment, the effects of radiation outside the system band and interference from outside the system band are not considered, and sudden fluctuations in the input level (for example, interference within the system band changes from nothing to existence). Fluctuation) is not taken into account. Therefore, a band limiting filter for realizing these functions and an AGC (Automatic Gain Control) that automatically controls the reception gain may be additionally introduced.

The D / A conversion unit 501 converts the baseband digital signal output from the radio signal processing arithmetic unit 103 into a baseband analog signal. The LPF unit 502 is a low-pass filter used to reduce the level of unnecessary high-frequency components generated after D / A conversion. The quadrature modulation unit 503 converts the baseband signal into a high frequency signal. The PA unit 504 is a power amplifier for wirelessly transmitting a high-frequency analog signal.

The LNA unit 506 is a low noise amplifier that amplifies the input signal to a level that can be processed in the subsequent stage. The orthogonal demodulator 507 converts the high frequency signal into a baseband signal. The LPF unit 508 is a low-pass filter used to reduce the level of unnecessary high frequency components. The A / D conversion unit 509 converts a baseband analog signal into a baseband digital signal.

The transmission / reception selector switch 505 is used to realize TDD communication within the frame. Since the transmission signal and the reception signal pass through the transmission / reception changeover switch 505 in the order shown in FIG. 3, the transmission signal is switched to the transmission side when each radio channel is a transmission channel, and the reception signal is switched to the reception side when the radio channel is a reception channel. Since the fixed radio station 13 side manages the timing of the radio channel, transmission / reception is always switched at the timing described above. On the other hand, on the mobile 23 side, since transmission / reception is switched at the timing synchronized with the radio signal transmitted by the fixed radio station 13, reception is always switched until timing synchronization is established, and after synchronization is established, transmission / reception is performed according to the timing. Switch.

FIG. 20 is a diagram showing a configuration example of the wireless transmission control arithmetic unit 102 on the mobile body 23 side of this embodiment.

In the wireless transmission control arithmetic unit 102 on the mobile body 23 side, the usage of the control information buffer 301 and the non-control information buffer 302 is the same as the wireless transmission control arithmetic unit 102 on the fixed radio station 13 side. The config information memory 303 stores the same information as the fixed radio station 13 side, but records the same config information as in FIG. 8 based on the result received by the broadcast channel, that is, the contents of the broadcast channel buffer 310.

The mobile management memory 304 has the same contents as in FIG. 9, but reads up and down and records channel allocation information. However, unlike the fixed radio station 13, only the information of the mobile 23 itself is recorded.

Similar to the fixed radio station 13, the scheduler 305 is activated at regular intervals (for example, every 100 ms). When the scheduler 305 is activated, it first refers to the broadcast information (FIG. 15) from the fixed radio station 13 and determines whether or not the mobile body 23 has a usable radio channel. When the mobile identifier to be assigned with respect to UCCH209, SCH211 or ACCH210 explicitly indicates the mobile 23, the contents of the control information buffer 301, the contents of the non-control information buffer 302, or the mobile 23. Transmission data is set in the MAC packet processing unit 306 in order to transmit the mobile identifier on each wireless channel. The data blocks generated by the MAC packet processing unit 306 are in the format shown in FIGS. 16, 14, and 17, respectively.

When transmitting UCCH209, the amount of data remaining in the uncontrolled information buffer 302, that is, the amount of uncontrolled information untransmitted data in FIG. 16 is transmitted each time. However, since the composition on the receiving side is hindered while the same data block is continuously transmitted, it is preferable not to update the amount of the data.

In the mobile body 23, unlike the fixed radio station 13, the timing of the system is indefinite immediately after the start-up, and the mobile body 23 is not connected to any fixed radio station 13. In this case, first, the radio signal processing arithmetic unit 103 of the mobile body 23 secures the timing synchronization with the fixed radio station 13 based on the reception timing of the preamble. Next, the mobile body 23 attempts to receive the broadcast channel (BCH) 207 output by the fixed radio station 13 that secures the timing synchronization. If the ACCH 210 (mobile identifier 0xFFFF) that can be freely used by any moving body 23 in the frame is notified by the notification channel 207, the moving body 23 attempts to transmit the ACCH 210. At this time, the moving body 23 itself may freely decide which channel of the ACCH 210 to use. If it is confirmed that the transmitted ACCH 210 is accepted by the fixed radio station 13 and at least one of the DCCH 208 and the UCCH 209 is assigned to the mobile 23 in the broadcast channel, the connection to the fixed radio station 13 is completed. In this embodiment, the scheduler 305 itself determines whether the mobile body 23 is not connected to the fixed radio station 13 in the state management.

FIG. 21 is a diagram showing an operation sequence at the time of handover.

Consider a mobile body 23, a fixed radio station 13A communicating with the mobile body 23, and a fixed radio station 13B as a handover destination. Each of the two fixed radio stations 13 transmits a broadcast channel to the mobile body 23 as a normal operation. The mobile body 23 receives the broadcast channels transmitted from the two fixed radio stations 13 in a wide band, and measures the average received power of all the frequency hopping channels and all the broadcast channels in the frame.

Next, based on this measurement result, the average received power for the broadcast channel hopping pattern of the fixed radio station 13A is used as a reference, and the power averaged for all hopping patterns other than the fixed radio station 13A is obtained. Then, using a level X [dB] lower than the reference value as a threshold value, the hopping pattern exceeding the threshold value with the maximum average received power is specified, and the frequency hopping offset and hopping interval are transmitted to the fixed radio station 13A by UCCH209. ..

When the fixed radio station 13 receives the UCCH 209, the fixed radio station 13 refers to the preset neighbor list, searches the table using the frequency hopping offset and the hopping interval received by the UCCH 209, identifies the fixed radio station 13B, and identifies the fixed radio station 13B. Request resource reservation for handover from 13B.

When the fixed radio station 13B receives the resource reservation request, it returns a positive response if there is a reservable control channel (DCCH208, UCCH209), or a negative response if it does not. When a positive response is returned, the ACCH 210 dedicated to the handover target mobile body is continuously secured for a certain period of time (for example, 1 second), and the allocation information of the ACCH 210 is transmitted by the BCH 207. The response from the fixed radio station 13B is notified from the fixed radio station 13A to the mobile body 23 by the DCCH 208. Here, when the mobile body 23 receives a negative response, it is advisable to redo the handover operation while still connected to the fixed radio station 13A.

When the mobile body 23 receives a positive response, it triggers the handover at its own timing. Specifically, when the average reception power of the hopping pattern of the fixed radio station 13B exceeds the threshold value Y [dB] lower than the average reception power of the fixed radio station 13A at the timing of the break of the continuous transmission of the control system channel. Trigger a handover. By the trigger of the handover, the mobile body 23 transmits the ACCH 210 dedicated to the mobile body to be handed over to the fixed radio station 13B. On the other hand, the fixed radio station 13B allocates the control system channel, and the allocation information is notified to the mobile body 23 by the BCH 207, so that the handover is completed.

Since the mobile body 23 does not transmit anything to the fixed radio station 13A after the establishment of communication with the fixed radio station 13B, the fixed radio station 13A continuously fails to receive the control information from the mobile body 23, and the embodiment As shown in 1, the communication is implicitly disconnected.

If a predetermined time elapses without receiving control channel allocation information from the fixed radio station 13B to the mobile 23, the mobile 23 determines that the handover has failed and continues communication with the fixed radio station 13A.

In order to realize the handover by the above procedure, some functions are added to the system of the first embodiment.

The first is to add an indicator of whether or not there is neighbor FH information to the MAC header of UCCH209 shown in FIG. 16 and information on the frequency hopping offset and the frequency hopping interval observed in the above procedure.

The second is to add a wideband reception function to the wireless signal processing arithmetic unit 103 of the mobile body 23. In parallel with the processing of the main signal shown in the first embodiment, the average received power of all the frequency hopping channels and the in-frame BCH 207 is measured, and the measurement result can be referred to from the wireless transmission control arithmetic unit 102.

The third is to add a function to the wireless transmission control arithmetic unit 102 of the mobile body 23 to specify the frequency hopping offset and the frequency hopping interval of the nearby fixed radio station 13 from the above-mentioned average received power information.

The fourth is a function of transmitting a reservation request message and a response message of the control system channel to the mobile body 23 to be handover to the wireless transmission control calculation device 102 of the fixed radio station 13 between the fixed radio stations 13 and resource reservation processing. Add the function to perform the above, and add a table that associates these combinations with the nearby fixed radio stations 13. Further, a function of identifying a nearby fixed radio station 13 corresponding to the combination from this table is added to the wireless transmission control arithmetic unit 102 of the mobile body 23.

Fifth, an indicator indicating that the resource reservation at the neighbor fixed radio station 13 has been completed is added to the MAC header of the DCCH 208 shown in FIG.

Sixth, a function of notifying X [dB] and Y [dB] used for the threshold calculation related to handover is added to the data structure of BCH 207 of FIG.

<Example 2>
In the third embodiment, the maintenance terminal device 17 operated by the system operator and the fixed radio station 13 are connected by a backbone network, and the instruction from the maintenance terminal device 17 is wireless transmission control calculation via the network interface device of the fixed radio station 13. The transmission line is extended in the system of the first embodiment or the second embodiment so as to be transmitted to the scheduler 305 in the apparatus 102.

By directly instructing the scheduler 305 from the maintenance terminal device 17 to the communication direction of the SCH 211 and the allocation information of the non-control system channel corresponding to the mobile identifier shown in FIG. 15, for example, to the mobile 23 in an emergency situation. The communication band can be allocated in an inclined manner for instructions and information collection from the mobile body 23. Even in the situation where the maintenance terminal device 17 directly instructs the scheduler 305, the notification channel (BCH) 207, the access control channel (ACCH) 210, and the control system channels (DCCH208, UCCH209) are controlled by the autonomous operation of the scheduler 305. Will be done.

The scheduler 305 may have two modes, a mode that operates completely autonomously as in the first and second embodiments, and a mode that follows the maintenance terminal device 17 only for non-control channel allocation, and the mode can be switched by the maintenance terminal. It is preferable that the device 17 manages it.

As described above, according to the embodiment of the present invention, the wireless frame transmits at least the control system channels (DCCH208, UCCH209) for transmitting information used for mobile control and information other than those used for mobile control. A non-control channel (SCH211), a broadcast channel (BCH207) for notifying all mobiles 23 of radio control information, and access control used to establish a connection from the mobile 23 to the fixed radio station 13. Including the channel (ACCH210), the fixed radio station 13 allocates at least one uplink (UCCH209) and downlink (DCCH208) channel pair of the control system channel to the mobile body 23 in the radio frame, and assigns the non-control system channel (UCCH210) to the mobile unit 23. The non-control system channel (SCH211) is dynamically assigned to the mobile body 23 by dynamically switching the upstream and downstream communication directions in the SCH211). Therefore, since the mobile body 23 to which the non-control system channel is assigned and the wireless frame can be flexibly changed in the communication direction (uplink, downlink), the communication band for controlling the mobile body 23 is continuously provided. At the same time, it is possible to allocate a large amount of communication band to a specific terminal. For example, the communication band can be obliquely allocated to the mobile 23, which needs to transmit a large amount of non-control system information in the event of an emergency. Further, by fixedly securing the upstream and downstream channels of the control system in each mobile body 23, the communication band for controlling the mobile body 23 can be continuously provided even in an emergency, and the mobile body 23 can be continuously provided. There is no problem in control.

Further, when the non-control system information to be transmitted is generated, the mobile body 23 uses at least one of the uplink control system channels (UCCH209) included in the channel pair assigned to the mobile body 23 to be used in the uplink non-control system. Since the allocation of the channel (SCH211) is requested to the fixed radio station 13, the allocation can be requested promptly by effectively utilizing the always assigned control system channel (UCCH209).

Further, the fixed radio station 13 is assigned to the mobile unit 23 and the non-control system channel (SCH211) when the fixed radio station 13 receives the request for allocation of the uplink non-control system channel (SCH211) or when the non-control system information to be transmitted is generated. Since the upstream or downstream communication direction of the non-control system channel is determined and the result of the determination is notified to all the moving bodies 23 using the notification channel (BCH207), it is not necessary to notify the moving bodies 23 individually. Line utilization efficiency can be improved. In addition, the mobile unit 23, which is not yet connected to the fixed radio station 13, can be notified of the allocation of the non-control system channel.

Further, when the fixed radio station 13 receives the instruction of the mobile body 23 having a high allocation priority and then receives the allocation request of the uplink non-control system channel (SCH211) from the mobile body 23, or transmits to the mobile body 23. When non-control system information to be generated occurs, the non-control system channel is preferentially assigned to the mobile body 23, so that the mobile body 23 requires transmission of a large amount of non-control system information in the event of an emergency. The communication band can be allocated in an inclined manner.

Further, since the fixed radio station 13 transmits the data block having the same content a plurality of times in the radio frame of the broadcast channel (BCH207), the channel allocation, which is important information, can be reliably notified to the mobile body 23.

Further, since the fixed radio station 13 transmits data blocks having the same contents a plurality of times at different frequencies within the radio frame of the broadcast channel (BCH207), fading countermeasures are taken by the effect of frequency diversity, and important information is used. It is possible to reliably notify the moving body 23 of a certain channel allocation.

In addition, each channel is composed of a guard interval, a preamble, or a plurality of data blocks, and the coding rate, interleave pattern, modulation method, and number of modulation symbols are set between channels and between a plurality of data blocks in the same channel. Since they are made equal, it is not necessary to have a hardware configuration corresponding to a plurality of methods, and the hardware can be easily configured.

Further, since each data block is composed of a phase reference symbol, a null symbol, and a differential QPSK modulation symbol, the degree of interference can be measured by the null symbol, and high-speed movement can be supported by the differential QPSK modulation.

Further, in the differential QPSK modulation, a logical frequency index is assigned to the phase reference symbol excluding the null symbol and the differential QPSK symbol, and differential modulation is performed between the symbols having the same frequency index, so that the symbols have a high correlation. By modulating between, the error rate can be reduced.

Further, when the fixed radio station 13 and the mobile body 23 fail to receive a part or all of the data blocks in the non-control system channel (SCH211), the data to be retransmitted on the control system channel (DCCH208, UCCH209). Since the block is specified, the control system channel (UCCH209) that is always assigned can be effectively utilized without providing a dedicated channel for transmitting the retransmission information, and the overhead can be reduced.

again,
The fixed radio station 13 determines whether the access control channel operates in a mode in which transmission from all mobile bodies 23 is permitted or a mode in which transmission from only a specific mobile body 23 is permitted. Since the result of the determination is notified to all the mobile bodies 23 using the notification channel, the success rate of handover can be improved.

Further, the mobile body 23 has a network interface device 101, a wireless transmission control calculation device 102, a radio signal processing calculation device 103, and a radio signal transmission / reception device 104, similarly to the fixed radio station 13, and the wireless transmission control calculation device 102. By switching the process executed by the fixed radio station 13 and the mobile body 23, either the fixed radio station 13 or the mobile body 23 can be configured, so that the program running on the same hardware can be changed. Only the fixed radio station 13 or the mobile body 23 can be configured.

The present invention is not limited to the above-described embodiment, and includes various modifications and equivalent configurations within the scope of the appended claims. For example, the above-described examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to those having all the described configurations. Further, a part of the configuration of one embodiment may be replaced with the configuration of another embodiment. Further, the configuration of another embodiment may be added to the configuration of one embodiment. In addition, other configurations may be added / deleted / replaced with respect to a part of the configurations of each embodiment.

Further, each of the above-described configurations, functions, processing units, processing means, etc. may be realized by hardware by designing a part or all of them by, for example, an integrated circuit, and the processor realizes each function. It may be realized by software by interpreting and executing the program to be executed.

Information such as programs, tables, and files that realize each function can be stored in a memory, a hard disk, a storage device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

In addition, the control lines and information lines indicate those that are considered necessary for explanation, and do not necessarily indicate all the control lines and information lines that are necessary for implementation. In practice, it can be considered that almost all configurations are interconnected.

11 ... Control information transmission device
12 ... Uncontrolled information transmission device 13 ... Fixed radio station 14 ... Wireless transmission device 15 ... Antenna 16 ... Backbone network 17 ... Maintenance terminal device 21 ... Control information transmission device 22 ... Uncontrollable information transmission device 23 ... Mobile body 24 ... Wireless transmission Device 25 ... Antenna 101 ... Network interface device 102 ... Wireless transmission control calculation device 103 ... Wireless signal processing calculation device 104 ... Wireless signal transmission / reception device 105 ... Packet buffer 106 ... Wireless transmission buffer 107 ... Wireless control memory 108 ... Signal processing memory 109 ... Common bus 110 ... Program memory 111 ... Boot processing device 201 ... Frame 202 ... Notification channel group 203 ... Downward moving body control information transmission channel 204 ... Upward moving body control information transmission channel 205 ... Access control channel 206 ... Non-control information sharing transmission channel 207 ... Notification channel 208 ... Downward moving body control information transmission channel 209 ... Upward moving body control information transmission channel 210 ... Access control channel 211 ... Uncontrolled information sharing transmission channel 221 ... Preamble 222 ... Data 223 ... Guard section 231 ... Phase reference symbol 232 ... Guard subcarrier and DC subcarrier 233 ... Data symbol 234 ... Null symbol 241 ... Logical subcarrier 301 ... Mobile control information buffer 302 ... Non-control information buffer 303 ... Config information memory 304 ... Mobile management memory 305 ... Scheduler 306 ... MAC packet processing unit 307 ... Access control unit 308 ... Mobile control channel buffer 309 ... Non-control channel buffer 310 ... Broadcast channel buffer 311 ... Access control channel buffer 401 ... Error detection code unit 402 ... Error correction code unit 403 ... Interleave. Repetition scrambler unit 404 ... DQPSK modulation unit 405 ... Resource mapping unit 406 ... IFFT unit 407 ... CP addition unit 408 ... Time multiplexing unit 409 ... Transmission side frequency shift unit 410 ... Reception side frequency shift unit 411 ... Preamble detection unit 412 ... FFT unit 413 ... Interference noise Power estimation unit 414 ... Demodulation processing unit 415 ... Deinterleaved scrambler unit 416 ... Probability synthesis unit 417 ... Error correction decoding unit 418 ... Error detection unit 501 ... Digital analog conversion unit 502 ... Low pass filter 503 ... Orthogonal modulation unit 504 ... Power amplifier 505 ... Transmission / reception switching unit 506 ... Low noise amplification unit 507 ... Orthogonal demodulation unit 508 ... Low pass filter 509 ... Analog / digital conversion unit

Claims (12)

A wireless communication method in a wireless communication system using a fixed station and a mobile station.
The wireless frame used in the wireless communication method includes at least a control channel for transmitting information used for mobile control, a non-control channel for transmitting information other than those used for mobile control, and all the mobile stations. It includes a broadcast channel for notifying radio control information and an access control channel used to establish a connection from the mobile station to the fixed station.
The fixed station
Within the radio frame, at least one uplink and downlink channel pair of the control system channel is assigned to the mobile station.
The upstream and downstream communication directions in the non-control system channel are dynamically switched, and the non-control system channel is dynamically assigned to the mobile station .
When the non-control system information to be transmitted is generated, the mobile station allocates the uplink non-control system channel by using at least one of the uplink control system channels included in the channel pair assigned to the mobile station. Request to a fixed station,
The fixed station allocates the non-control system channel when it receives the request for allocating the upstream non-control system channel or when the non-control system information to be transmitted occurs, and the mobile station that allocates the non-control system channel and the uplink or downlink of the non-control system channel. a wireless communication method of a communication direction is determined, characterized that you notify the result of the decision to all the mobile station using the broadcast channel. The wireless communication method according to claim 1.
After receiving an instruction from a mobile station having a high allocation priority, the fixed station receives an allocation request for the uplink non-control system channel from the mobile station, or generates non-control system information to be transmitted to the mobile station. A wireless communication method characterized in that a non-control system channel is preferentially assigned to the mobile station in the case of the above. The wireless communication method according to claim 1.
A wireless communication method characterized in that the fixed station transmits a data block having the same content a plurality of times within a wireless frame of the broadcast channel. The wireless communication method according to claim 3.
A wireless communication method characterized in that the fixed station transmits a data block having the same content a plurality of times at different frequencies within a wireless frame of the broadcast channel. The wireless communication method according to claim 1.
Each of the control system channel, the non-control system channel, the broadcast channel, and the access control channel is composed of a guard section, a preamble, or a plurality of data blocks.
A wireless communication method characterized by equalizing the coding rate, interleave pattern, modulation method, and number of modulation symbols between different channels and between a plurality of data blocks in the same channel. The wireless communication method according to claim 5.
A wireless communication method, wherein each of the one or a plurality of data blocks is composed of a phase reference symbol, a null symbol, and a differential QPSK modulation symbol. The wireless communication method according to claim 6.
The differential QPSK modulation is a wireless communication method characterized in that a logical frequency index is assigned to a phase reference symbol excluding a null symbol and a differential QPSK symbol, and differential modulation is performed between the symbols having the same frequency index. .. The wireless communication method according to claim 5.
The fixed station and the mobile station are characterized in that, when reception of a part or all of the data blocks in the non-control system channel fails, the data block to be retransmitted in the control system channel is designated. Wireless communication method. The wireless communication method according to claim 1.
The fixed station determines whether the access control channel operates in a mode that allows transmission from all mobile stations or a mode that allows transmission from only a specific mobile station, and determines whether the access control channel operates in a mode that allows transmission from only a specific mobile station. A wireless communication method characterized in that the result is notified to all the mobile stations using the notification channel. A wireless communication system in which a fixed station and a mobile station communicate with each other.
The radio frame used for communication between the fixed station and the mobile station includes at least a control channel that transmits information used for mobile control, a non-control channel that transmits information other than that used for mobile control, and the like. It includes a broadcast channel that notifies all the mobile stations of radio control information and an access control channel that is used to establish a connection from the mobile station to the fixed station.
The fixed station
A network interface device that provides a communication interface function with other systems,
A wireless transmission control arithmetic unit that provides a scheduling function and an access control function related to wireless communication transmission,
A wireless signal processing arithmetic device that mutually converts a bit sequence transmitted wirelessly and a baseband digital signal to provide error detection and error correction functions.
It has a wireless signal transmitter / receiver that converts baseband digital signals and high-frequency analog signals to each other and provides an interface function on the wireless side.
The wireless transmission control arithmetic unit allocates at least one uplink and downlink channel pair of the control system channel to the mobile station in the wireless frame, and dynamically sets the uplink and downlink communication directions in the non-control system channel. Has a function of dynamically allocating the non-control system channel to the mobile station by switching to
When the non-control system information to be transmitted is generated, the mobile station allocates the uplink non-control system channel by using at least one of the uplink control system channels included in the channel pair assigned to the mobile station. Request to a fixed station,
The fixed station allocates the non-control system channel when it receives the request for allocating the upstream non-control system channel or when the non-control system information to be transmitted occurs, and the mobile station that allocates the non-control system channel and the uplink or downlink of the non-control system channel. A wireless communication system characterized in that the communication direction of the mobile station is determined and the result of the determination is notified to all the mobile stations using the notification channel. The wireless communication system according to claim 10.
Like the fixed station, the mobile station has a network interface device, a wireless transmission control arithmetic unit, a wireless signal processing arithmetic unit, and a wireless signal transmission / reception device.
A wireless communication system characterized in that either the fixed station or the mobile station can be configured by switching the process executed by the wireless transmission control arithmetic unit between a fixed station and a mobile station. A program for controlling fixed stations in a wireless communication system using fixed stations and mobile stations.
The radio frame used for communication between the fixed station and the mobile station includes at least a control system channel that transmits information used for mobile control, a non-control channel that transmits information other than that used for mobile control, and the like. It includes a broadcast channel that notifies all the mobile stations of radio control information and an access control channel that is used to establish a connection from the mobile station to the fixed station.
The program
A procedure for assigning at least one uplink and downlink channel pair of the control system channel to the mobile station in the radio frame, and
A procedure for dynamically switching the upstream and downstream communication directions of the non-control system channel and dynamically allocating the non-control system channel to the mobile station.
When non-control system information to be transmitted by the mobile station is generated, a request for allocation of the uplink non-control system channel is performed using at least one of the uplink control system channels included in the channel pair assigned to the mobile station. And the procedure to receive
When the request for allocation of the uplink non-control system channel is received or the non-control system information to be transmitted occurs, the mobile station to which the non-control system channel is assigned and the uplink or downlink communication direction of the non-control system channel are determined. A program for causing the fixed station to execute a procedure of notifying all the mobile stations of the result of the determination using the broadcast channel.

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