WO2021210043A1 - Control station, sending station, data transmission system, control circuit, storage medium, and data transmission control method - Google Patents

Abstract

A data transmission system in which a sending station (300) that performs delta-sigma modulation sends data to a receiving station, wherein a control station (100) that controls the operation of the sending station (300) comprises: a frequency control unit (104) that generates channel placement information indicating the allocation of channels, which are units of frequency division, to each beam; a zero point control unit (103) that changes the zero point placement of the delta-sigma modulation and generates zero point placement information indicating the zero point placement each time a change occurs; and a computation processing unit (105) that uses the channel placement information and the zero point placement information to determine the zero point placement used by the sending station (300).

Description

Control station, transmission station, data transmission system, control circuit, storage medium and data transmission control method

The present disclosure relates to a control station, a transmission station, a data transmission system, a control circuit, a storage medium, and a data transmission control method for controlling data transmission of a transmission station.

The satellite communication system is widely used as a communication means for ships and aircraft on the sea where the terrestrial communication network cannot be used, and is also used as an effective communication means in the event of a disaster. In the future, satellite communication systems are also expected to be used as backhaul lines for terrestrial networks toward the practical application of 5th generation mobile communication systems. In this way, the role of satellite communication systems is expected to increase. On the other hand, the satellite communication system has a problem of a large cost for assembling and launching a satellite, and it is necessary to reduce the cost. Since the launch cost depends on the size and weight of the satellite, the miniaturization and weight reduction of the satellite have a great influence on the cost reduction. Therefore, small and lightweight satellite-mounted devices are required, and delta-sigma modulators are attracting attention.

Delta-sigma modulation is a modulation method that has noise shaping characteristics that reduce quantization noise in the signal band. Delta-sigma modulation is attracting attention as a technology that leads to cost reduction of satellite communication systems because it eliminates the need for analog DAC (Digital Analog Converter), which was required in conventional configurations. Delta-sigma modulation suppresses noise in the passband where the signal is placed, moves the noise out of the passband, and uses an analog filter to remove the noise outside the passband. However, even in the delta-sigma modulation, the noise that could not be suppressed remains in the pass band in which the noise is suppressed, and the noise is divided into a portion where the noise is greatly raised and a portion where the noise is reduced in the pass band. The position of the notch on the frequency axis is determined by the zero arrangement of the delta-sigma modulator. Patent Document 1 discloses a technique for controlling noise outside the pass band by controlling the zero arrangement in a wireless communication system to alleviate design requirements for an analog filter.

Japanese Unexamined Patent Publication No. 2004-222265

However, according to the above-mentioned conventional technology, the purpose is to alleviate the design requirements of the analog filter, and the noise in the pass band is not examined. Therefore, depending on the signal arrangement, most of the signal overlaps with noise and the signal reception quality, for example, SINR (Signal to Interference plus Noise Ratio) deteriorates, that is, when the notch position in the pass band is not suitable for the channel arrangement. Has a problem that the SINR of the channel is lowered. Further, when transmitting using a plurality of channels, the SINR for each channel may differ depending on the positional relationship between the channel arrangement and the notch position.

Communication devices such as multi-beam satellites that irradiate the service area with multiple beams change the frequency band used for each beam, and repeatedly use the same frequency band for beams with a large distance between beams and a small effect of interference. It improves frequency utilization efficiency. The communication device can improve the SINR of the channel in its own beam by narrowing the pass band of the delta-sigma modulation according to the signal band to be used. However, since the communication device cannot change the characteristics of the analog filter that removes the noise outside the pass band, a large noise is generated between the narrowed pass band and the noise removed by the analog filter. Since the frequency of the part where a large noise is generated is used by another beam, it will interfere with the other beam. Therefore, the communication device needs to improve the SINR of the channel without narrowing the pass band of the delta-sigma modulation.

The present disclosure has been made in view of the above, and is a control station capable of controlling a transmitting station that performs delta-sigma modulation to improve reception quality at a receiving station that receives a signal from the transmitting station. The purpose is to obtain.

In order to solve the above-mentioned problems and achieve the object, the present disclosure is a control station that controls the operation of a transmitting station in a data transmission system in which a transmitting station that performs delta-sigma modulation transmits data to a receiving station. The control station changes the frequency control unit that generates channel arrangement information indicating the allocation of channels, which are units that divide the frequency, to each beam, and the zero arrangement of delta sigma modulation, and changes the zero arrangement that indicates the zero arrangement each time. It is characterized by including a zero point control unit that generates arrangement information, and an arithmetic processing unit that determines the zero point arrangement used by the transmitting station by using the channel arrangement information and the zero point arrangement information.

The control station according to the present disclosure has an effect that the transmitting station that performs delta-sigma modulation can be controlled to improve the reception quality at the receiving station that receives the signal from the transmitting station.

The figure which shows the structural example of the data transmission system which concerns on Embodiment 1. A first block diagram showing a configuration example of a control station according to the first embodiment. A second block diagram showing a configuration example of the control station according to the first embodiment. A third block diagram showing a configuration example of the control station according to the first embodiment. Block diagram showing a configuration example of a transmitting station according to the first embodiment A block diagram showing a configuration example of a relay unit included in the transmitting station according to the first embodiment. A block diagram showing a configuration example of a transmission frequency conversion unit included in the relay unit according to the first embodiment. A flowchart showing the operation of the control station according to the first embodiment. The figure which shows the relationship between the pass band and noise in the transmission station of the data transmission system which concerns on Embodiment 1. The first figure which shows the relationship between the zero point arrangement and the channel arrangement in the transmission station of the data transmission system which concerns on Embodiment 1. FIG. 2 is a second diagram showing the relationship between the zero point arrangement and the channel arrangement in the transmitting station of the data transmission system according to the first embodiment. A flowchart showing the operation of the transmitting station according to the first embodiment. The figure which shows the structural example of the processing circuit when the processing circuit provided in the control station which concerns on Embodiment 1 is realized by a processor and a memory. The figure which shows the example of the processing circuit in the case where the processing circuit provided in the control station which concerns on Embodiment 1 is configured by exclusive hardware. A block diagram showing a configuration example of a control station according to the second embodiment. A flowchart showing the operation of the control station according to the second embodiment. A flowchart showing the operation of the transmitting station according to the second embodiment.

Hereinafter, the control station, the transmission station, the data transmission system, the control circuit, the storage medium, and the data transmission control method according to the embodiment of the present disclosure will be described in detail with reference to the drawings.

Embodiment 1.
FIG. 1 is a diagram showing a configuration example of the data transmission system 500 according to the first embodiment. The data transmission system 500 includes a control station 100, a receiving station 200, and a transmitting station 300. In the data transmission system 500, the control station 100 and the transmission station 300 are connected by wireless communication for communication, and the reception station 200 and the transmission station 300 are connected and communicate by wireless communication. The data transmission system 500 is a system in which a transmitting station 300 that performs delta-sigma modulation transmits data to a receiving station 200, and a control station 100 controls the operation of the transmitting station 300. In FIG. 1, the number of receiving stations 200 is two, but this is an example and is not limited thereto. In the data transmission system 500, the number of receiving stations 200 may be one or three or more. The data transmission system 500 assumes a satellite radio system in which a transmission station 300 that performs delta sigma modulation is mounted on the satellite, but the application of the data transmission system 500 is not limited to this.

The configuration of each device included in the data transmission system 500 will be described. Since the receiving station 200 does not have a specific feature in the present embodiment, detailed description thereof will be omitted.

First, the configuration of the control station 100 will be described. FIG. 2 is a first block diagram showing a configuration example of the control station 100 according to the first embodiment. The control station 100 includes a control information transmission / reception unit 101, a filter control unit 102, a zero point control unit 103, a frequency control unit 104, and an arithmetic processing unit 105.

The frequency control unit 104 determines the allocation of channels, which are units of divided frequencies, to each beam in the frequency band used by the transmitting station 300 for data transmission, that is, the pass band. The frequency control unit 104 generates channel arrangement information indicating the allocation of channels to each beam, that is, the channel arrangement in the frequency band used by the transmitting station 300 for data transmission, and the control information transmission / reception unit 101 and the arithmetic processing unit 105. Output to.

The zero point control unit 103 determines the zero point arrangement of the delta sigma modulation in the frequency band used by the transmitting station 300 for data transmission, that is, the pass band. The zero point control unit 103 generates zero point arrangement information indicating the zero point arrangement and outputs it to the arithmetic processing unit 105. The zero point control unit 103 changes the zero point arrangement of the delta-sigma modulation, generates zero point arrangement information indicating the zero point arrangement each time the change is made, and outputs the zero point arrangement information to the arithmetic processing unit 105. Further, the zero point control unit 103 outputs the zero point arrangement information indicating the zero point arrangement when the zero point arrangement used by the transmitting station 300 is determined by the arithmetic processing unit 105 to the filter control unit 102.

The arithmetic processing unit 105 determines the zero point arrangement to be used by the transmitting station 300 by using the channel arrangement information acquired from the frequency control unit 104 and the zero point arrangement information acquired from the zero point control unit 103. Specifically, the arithmetic processing unit 105 derives the reception quality estimated value in the receiving station 200 by using the channel arrangement information and the zero point arrangement information. The reception quality estimate includes, but is not limited to, for example, data transmitted from the transmitting station 300 to the receiving station 200, that is, the average SINR of the transmission signal, the degree of satisfaction with the request, the amount of interference, and the like. The reception quality estimate may be defined by at least one or more of the average SINR of the transmitted signal, the satisfaction with the requirement, and the amount of interference. The arithmetic processing unit 105 determines the zero point arrangement used by the transmitting station 300 based on the derived reception quality estimated value. When the arithmetic processing unit 105 determines the zero point arrangement to be used by the transmitting station 300, the arithmetic processing unit 105 notifies the zero point control unit 103 to that effect.

The filter control unit 102 derives the coefficient of the filter so that the zero point arrangement is determined by the zero point control unit 103. The filter control unit 102 outputs filter information indicating the coefficient of the derived filter to the control information transmission / reception unit 101.

The control information transmission / reception unit 101 transmits the channel arrangement information acquired from the frequency control unit 104 and the filter information acquired from the filter control unit 102 to the transmission station 300 as control information.

In addition, when the control station 100 can obtain the zero point arrangement from which good reception quality can be obtained from the channel arrangement information by calculation, it is not necessary to change the zero point arrangement according to the reception quality estimated value, so that the zero point control unit 103 It is not necessary to output the zero point arrangement information to the arithmetic processing unit 105. FIG. 3 is a second block diagram showing a configuration example of the control station 100 according to the first embodiment. The control station 100 shown in FIG. 3 omits the output from the zero point control unit 103 to the arithmetic processing unit 105 as compared with the control station 100 shown in FIG.

Further, the control station 100 may use the actual reception quality of the reception station 200 without deriving the reception quality estimated value internally. FIG. 4 is a third block diagram showing a configuration example of the control station 100 according to the first embodiment. The control station 100 shown in FIG. 4 omits the arithmetic processing unit 105 as compared with the control station 100 shown in FIG. In the control station 100 shown in FIG. 4, the control information transmission / reception unit 101 receives the reception quality information at the actual reception station 200 via the transmission station 300, and outputs the reception quality information to the zero point control unit 103. In the data transmission system 500, it is assumed that the receiving station 200 transmits the reception quality information measured by its own station to the transmitting station 300.

Next, the configuration of the transmitting station 300 will be described. FIG. 5 is a block diagram showing a configuration example of the transmitting station 300 according to the first embodiment. The transmission station 300 includes a relay unit 301 and a transmission unit 302. The transmission unit 302 generates data to be transmitted to the receiving station 200. The relay unit 301 relays the signal, that is, the data generated by the transmission unit 302, and transmits the data to the receiving station 200.

FIG. 6 is a block diagram showing a configuration example of the relay unit 301 included in the transmitting station 300 according to the first embodiment. The relay unit 301 includes a control information transmission / reception unit 311, an antenna 320, a reception frequency conversion unit 321 and a channelizer 331, a transmission frequency conversion unit 341, and an antenna 342. The control information transmission / reception unit 311 receives control information from the control station 100 and controls the operation of each configuration constituting the relay unit 301. The reception frequency conversion unit 321 converts the frequency of the signal, that is, the data received from the transmission unit 302. The reception frequency conversion unit 321 may receive the data from the transmission unit 302 by the antenna 320, or may acquire the data by wire without the antenna 320. The channelizer 331 demultiplexes the frequency-converted signal, that is, the data in the reception frequency conversion unit 321. The channelizer 331 outputs the demultiplexed data to the transmission frequency conversion unit 341 corresponding to the beam to be transmitted. The transmission frequency conversion unit 341 changes the filter coefficient of the delta-sigma modulator based on the control information, and converts the frequency of the demultiplexed data into the transmission frequency. The transmission frequency conversion unit 341 transmits the data after conversion to the transmission frequency from the antenna 342.

In the example of FIG. 6, the relay unit 301 includes three antennas 320, a reception frequency conversion unit 321 and a transmission frequency conversion unit 341, and an antenna 342, but this is an example and is not limited thereto. The relay unit 301 may include two or less, or four or more antennas 320, a reception frequency conversion unit 321, a transmission frequency conversion unit 341, and an antenna 342. Further, in FIG. 6, the control information transmission / reception unit 311 and one transmission frequency conversion unit 341 are connected, but in reality, the control information transmission / reception unit 311 and all transmission frequency conversion units 341 are connected. It shall be.

FIG. 7 is a block diagram showing a configuration example of the transmission frequency conversion unit 341 included in the relay unit 301 according to the first embodiment. The transmission frequency conversion unit 341 includes a filter 351, a quantizer 361, a filter 371, and an adder 381. The filter 351 is a filter for performing delta-sigma modulation. The quantizer 361 quantizes the signal after passing through the filter 351. The filter 371 is a filter for suppressing noise outside the pass band. The adder 381 feeds back the signal output from the quantizer 361. In the transmission frequency conversion unit 341, the zero point arrangement can be changed by changing the tap coefficient of the filter 351. The order of the delta sigma modulation is determined by the number of tap coefficients. The maximum number of notches generated in delta-sigma modulation is equal to the order of delta-sigma modulation. Also, the number of zeros to be set is equal to the order of delta-sigma modulation.

Next, in the data transmission system 500, the operation of each device and the control method of the control station 100 when data is transmitted from the transmission station 300 to the reception station 200 will be described. In general, a satellite equipped with a channelizer divides a frequency into units called channels and assigns the channel to a beam to realize frequency allocation. In this embodiment, the frequency control unit 104 of the control station 100 determines the channel used by each beam. Here, if the same channel is used in a plurality of beams, frequency resources can be efficiently used in many beams, but if the interval between beams using the same channel becomes too narrow, interference will occur for each channel. The capacity becomes small, and as a result, the capacity of the data transmission system 500, that is, the amount of data communication is reduced. Therefore, the frequency control unit 104 of the control station 100 needs to allocate an appropriate channel to the beam. As a method for determining the frequency band used by each beam, for example, there is an allocation method that minimizes the amount of interference between the beams.

FIG. 8 is a flowchart showing the operation of the control station 100 according to the first embodiment. In the control station 100, the zero point control unit 103 makes a tentative determination of the zero point arrangement, and outputs the zero point arrangement information to the arithmetic processing unit 105 (step S101). The arithmetic processing unit 105 acquires zero point arrangement information from the zero point control unit 103. Further, the arithmetic processing unit 105 acquires channel arrangement information indicating the allocation of channels to each beam from the frequency control unit 104. The arithmetic processing unit 105 derives a reception quality estimate for the zero point arrangement tentatively determined by the zero point control unit 103 in the beam channel arrangement determined by the frequency control unit 104 (step S102).

The arithmetic processing unit 105 determines whether or not the derived reception quality estimated value is equal to or higher than the specified threshold value (step S103). When the derived reception quality estimated value is less than the specified threshold value (step S103: No), the arithmetic processing unit 105 confirms with the zero point control unit 103 whether or not zero point arrangement candidates remain (step S104). .. When the zero point arrangement candidate remains (step S104: Yes), the arithmetic processing unit 105 instructs the zero point control unit 103 to temporarily determine the next zero point arrangement. The zero point control unit 103 makes a tentative determination of the next zero point arrangement, and outputs the zero point arrangement information to the arithmetic processing unit 105 (step S105). The arithmetic processing unit 105 derives a reception quality estimate for the zero point arrangement tentatively determined by the zero point control unit 103 in the beam channel arrangement determined by the frequency control unit 104 (step S102).

Here, the relationship between the zero point arrangement and the channel arrangement will be explained. FIG. 9 is a diagram showing the relationship between the pass band and noise in the transmission station 300 of the data transmission system 500 according to the first embodiment. As described above, the transmitting station 300 reduces noise in the pass band by delta-sigma modulation. However, in the pass band, a portion where the noise is greatly raised and a portion where the noise is reduced are generated.

FIG. 10 is a first diagram showing the relationship between the zero point arrangement and the channel arrangement in the transmission station 300 of the data transmission system 500 according to the first embodiment. In FIG. 10, #A indicates channel #A and #B indicates channel #B. The same applies to FIG. 11 described later. When the channel #A and the noise have a positional relationship as shown in FIG. 10, the reception quality estimated value is low because the channel #A overlaps the noisy portion. Further, when the channel #B and the noise have a positional relationship as shown in FIG. 10, the channel #B has a wide channel width, but the number of notches overlapping the channel #B is only one, so that the channel #B is referred to as the channel #B. There is a lot of overlapping noise. In such a case, the data transmission system 500 can expect an improvement in the reception quality estimate of each channel by changing the zero point arrangement and shifting the notch position.

FIG. 11 is a second diagram showing the relationship between the zero point arrangement and the channel arrangement in the transmission station 300 of the data transmission system 500 according to the first embodiment. As shown in FIG. 11, the data transmission system 500 is arranged so that each channel and the notch overlap each other, and a plurality of notches are arranged so as to overlap each other for a wide channel, so that the reception quality estimate value can be obtained. Improvement is possible. However, the notch position with good reception quality changes depending on the number and arrangement of channels. Therefore, the data transmission system 500 needs to derive a reception quality estimate from a plurality of zero point arrangement candidates.

In the data transmission system 500, the control station 100 repeats the process of tentatively determining the zero arrangement and deriving the reception quality estimated value until the reception quality estimated value becomes equal to or higher than the specified threshold value. In the present embodiment, the control station 100 sets notch candidate points for each fixed frequency in the pass band, and derives a reception quality estimate for each combination of notch candidate points. The number of notches candidate points is m, when the order of the delta sigma modulator is an n _o, all combinations C _z1 of the choice of zeros can be represented by the following formula (1) for a duplicate combinations ..

In the control station 100, the arithmetic processing unit 105 derives a reception quality estimated value of a combination of zero point arrangements of _{up to C z1.} Regarding the method of determining the zero point arrangement, the arithmetic processing unit 105 derives and records the reception quality estimated values for all combinations that select notches for the order from the notch candidate points, and determines whether or not the value is equal to or greater than the threshold value. You may.

Return to the explanation of the flowchart of FIG. The arithmetic processing unit 105 determines whether or not the derived reception quality estimated value is equal to or higher than the specified threshold value (step S103). When the derived reception quality estimated value is equal to or higher than the specified threshold value (step S103: Yes), the arithmetic processing unit 105 determines the zero point arrangement (step S106). When the arithmetic processing unit 105 determines the zero point arrangement to be used by the transmitting station 300, the arithmetic processing unit 105 notifies the zero point control unit 103 to that effect. The zero point control unit 103 outputs the zero point arrangement information indicating the tentatively determined zero point arrangement to the filter control unit 102. At this time, the arithmetic processing unit 105 independently determines the zero point arrangement for each beam. The zero point control unit 103 outputs zero point arrangement information for all beams to the filter control unit 102.

The filter control unit 102 derives the coefficient of the filter based on the zero point arrangement information and outputs the filter information to the control information transmission / reception unit 101. The control information transmission / reception unit 101 transmits the channel arrangement information acquired from the frequency control unit 104 and the filter information acquired from the filter control unit 102 to the transmission station 300 as control information (step S107). If there are no zero point arrangement candidates left (step S104: No), the arithmetic processing unit 105 does not determine the zero point arrangement, and the control station 100 ends the operation of the flowchart shown in FIG. In this way, in the control station 100, the arithmetic processing unit 105 determines the zero point arrangement so that the reception quality estimated value becomes equal to or higher than the defined threshold value. When the derived reception quality estimated value is less than the specified threshold value, the arithmetic processing unit 105 causes the zero point control unit 103 to change the zero point arrangement so that the received quality estimated value becomes equal to or more than the specified threshold value.

The control station 100 may use an optimization algorithm such as a genetic algorithm in order to shorten the processing time according to the flowchart shown in FIG. Further, when the zero point arrangement in which good reception quality can be obtained can be obtained from the channel arrangement information by calculation, the zero point control unit 103 outputs the zero point arrangement in which good reception quality can be obtained from the channel arrangement information to the filter control unit 102. do.

Next, the operation of the transmitting station 300 that has received the control information from the control station 100 will be described. FIG. 12 is a flowchart showing the operation of the transmitting station 300 according to the first embodiment. In the transmission station 300, the control information transmission / reception unit 311 receives control information from the control station 100 (step S201). The control information transmission / reception unit 311 outputs control information to the transmission frequency conversion unit 341 of the corresponding beam. The transmission frequency conversion unit 341 sets the coefficient of the filter based on the filter information included in the control information (step S202).

When the transmission station 300 is mounted on the satellite, the data transmission system 500 may be configured to mount the function of the control station 100 on the satellite and connect the control station 100 and the control unit of the satellite. ..

Next, the hardware configuration of the control station 100 will be described. In the control station 100, the control information transmission / reception unit 101, the filter control unit 102, the zero point control unit 103, the frequency control unit 104, and the arithmetic processing unit 105 are realized by a processing circuit. The processing circuit may be a processor and memory for executing a program stored in the memory, or may be dedicated hardware. The processing circuit is also called a control circuit.

FIG. 13 is a diagram showing a configuration example of the processing circuit 90 when the processing circuit included in the control station 100 according to the first embodiment is realized by a processor and a memory. The processing circuit 90 shown in FIG. 13 is a control circuit and includes a processor 91 and a memory 92. When the processing circuit 90 is composed of the processor 91 and the memory 92, each function of the processing circuit 90 is realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in the memory 92. In the processing circuit 90, each function is realized by the processor 91 reading and executing the program stored in the memory 92. That is, the processing circuit 90 includes a memory 92 for storing a program in which the processing of the control station 100 is eventually executed. It can be said that this program is a program for causing the control station 100 to execute each function realized by the processing circuit 90. This program may be provided by a storage medium in which the program is stored, or may be provided by other means such as a communication medium.

In the above program, the frequency control unit 104 generates channel arrangement information indicating the allocation of channels, which are units for dividing the frequency, to each beam, and the zero point control unit 103 performs the zero point arrangement of delta sigma modulation. The second step of generating zero point arrangement information indicating the zero point arrangement each time the change is made, and the arithmetic processing unit 105 uses the channel arrangement information and the zero point arrangement information to determine the zero point arrangement used by the transmission station 300. It can be said that it is a program that causes the control station 100 to execute the third step of determining.

Here, the processor 91 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), or the like. The memory 92 is, for example, non-volatile or volatile such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (registered trademark) (Electrically EPROM). This includes semiconductor memory, magnetic disks, flexible disks, optical disks, compact disks, mini disks, DVDs (Digital Versatile Disc), and the like.

FIG. 14 is a diagram showing an example of a processing circuit 93 when the processing circuit included in the control station 100 according to the first embodiment is configured by dedicated hardware. The processing circuit 93 shown in FIG. 14 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The thing is applicable. As for the processing circuit, a part may be realized by dedicated hardware and a part may be realized by software or firmware. As described above, the processing circuit can realize each of the above-mentioned functions by the dedicated hardware, software, firmware, or a combination thereof.

Although the hardware configuration of the control station 100 has been described, the hardware configuration of the transmission station 300 is the same as the hardware configuration of the control station 100.

As described above, according to the present embodiment, in the data transmission system 500, the control station 100 sets the zero point arrangement according to the channel arrangement of the transmission station 300 that performs delta-sigma modulation, and adjusts the notch position. I decided. As a result, the data transmission system 500 can improve the reception quality at the reception station 200 that receives the signal from the transmission station 300. The data transmission system 500 can improve the reception quality at the reception station 200 without changing the hardware configuration of the transmission station 300.

Embodiment 2.
In the first embodiment, the case of selecting the zero point arrangement in which good reception quality can be obtained has been described. In the second embodiment, a case where a channel arrangement that obtains good reception quality is selected in addition to the zero point arrangement will be described.

In the second embodiment, the configuration of the data transmission system 500 is the same as the configuration of the data transmission system 500 of the first embodiment shown in FIG. In the data transmission system 500, when the zero point arrangement is changed and the notch position is shifted, noise becomes large in the frequency band in which the signal is not arranged. This noise is not a problem for beams with staggered notches, but it interferes with other beams that use that frequency band. Therefore, it is necessary to consider the zero point arrangement and channel arrangement including the influence on other beams.

FIG. 15 is a block diagram showing a configuration example of the control station 100 according to the second embodiment. In the second embodiment, when the derived reception quality estimate does not reach the specified threshold value, the frequency control unit 104 outputs another channel arrangement candidate to the arithmetic processing unit 105.

FIG. 16 is a flowchart showing the operation of the control station 100 according to the second embodiment. In the present embodiment, the control station 100 realizes further improvement in reception quality by repeatedly performing tentative determination and evaluation for the channel arrangement not specified in the first embodiment.

In the control station 100, the frequency control unit 104 makes a tentative determination of the channel arrangement of all beams and outputs the channel arrangement information to the arithmetic processing unit 105 (step S301). The zero point control unit 103 tentatively determines the zero point arrangement of all beams, and outputs the zero point arrangement information to the arithmetic processing unit 105 (step S302). The arithmetic processing unit 105 acquires the channel arrangement information from the frequency control unit 104, and acquires the zero point arrangement information from the zero point control unit 103. The arithmetic processing unit 105 derives a reception quality estimate for the channel arrangement tentatively determined by the frequency control unit 104 and the zero point arrangement tentatively determined by the zero point control unit 103 (step S303).

When deriving the reception quality estimated value, the arithmetic processing unit 105 must consider not only the own beam but also the interference from other beams. If the channel assigned to the own beam is also assigned to another beam, the channel assigned to the own beam will be interfered with. In other beams, the shape of noise changes depending on the zero arrangement, but the noise in the frequency band of the channel used in the own boom interferes with the own beam. For this reason, the arithmetic processing unit 105 needs the channel arrangement and zero point arrangement of the own beam, the channel arrangement and zero point arrangement of the other beam, and the distance information between the beams in order to derive the reception quality estimated value. Therefore, the arithmetic processing unit 105 also acquires information about other beams from the frequency control unit 104 and the zero point control unit 103.

The arithmetic processing unit 105 determines whether or not the derived reception quality estimated value is equal to or higher than the specified threshold value (step S304). When the derived reception quality estimate is less than the specified threshold value (step S304: No), the arithmetic processing unit 105 confirms with the zero point control unit 103 whether or not zero point arrangement candidates remain (step S305). .. When the zero point arrangement candidate remains (step S305: Yes), the arithmetic processing unit 105 instructs the zero point control unit 103 to temporarily determine the next zero point arrangement. The zero point control unit 103 makes a tentative determination of the next zero point arrangement, and outputs the zero point arrangement information to the arithmetic processing unit 105 (step S306).

At this time, the number of candidates C _z2 placement zeros, the number of notches candidate points is m, the order of the delta sigma modulator is n _o, if the number of beams is a n _b, represented by the following formula (2) be able to.

In the second embodiment, since the zero-point arrangements of all the beams affect each other, it is necessary to consider the combination of the zero-point arrangements of all the beams. Therefore, the combination of the beam number multiplication of the combination of the zero point arrangements in one beam is the candidate number of the zero point arrangements in the second embodiment. The control station 100 derives reception quality estimates for all candidates for zero placement, and changes channel placement candidates when the reception quality estimates do not reach a defined threshold. The number of channels is n _c, the number of request channels at the beam i and n _i, if the condition of assigning channel requests content to total beam, all combinations C _c of the number of channels, the following equation (3) Can be represented.

In the second embodiment, the arithmetic processing unit 105 derives a reception quality estimate of a combination of zero point arrangements of _{up to C z2} × C _c.

Return to the explanation of the flowchart of FIG. The arithmetic processing unit 105 derives a reception quality estimate for the channel arrangement tentatively determined by the frequency control unit 104 and the zero point arrangement tentatively determined by the zero point control unit 103 (step S303). The arithmetic processing unit 105 determines whether or not the derived reception quality estimated value is equal to or higher than the specified threshold value (step S304). When the derived reception quality estimate is less than the specified threshold value (step S304: No), the arithmetic processing unit 105 confirms with the zero point control unit 103 whether or not zero point arrangement candidates remain (step S305). .. When there are no zero point arrangement candidates remaining (step S305: No), the arithmetic processing unit 105 initializes the zero point arrangement candidates tentatively determined by the zero point control unit 103 (step S307). The arithmetic processing unit 105 confirms with the frequency control unit 104 whether or not channel arrangement candidates remain (step S308). When the channel arrangement candidate remains (step S308: Yes), the arithmetic processing unit 105 instructs the frequency control unit 104 to tentatively determine the next channel arrangement. The frequency control unit 104 makes a tentative determination of the next channel arrangement, and outputs the channel arrangement information to the arithmetic processing unit 105 (step S309).

The arithmetic processing unit 105 derives a reception quality estimate for the channel arrangement tentatively determined by the frequency control unit 104 and the zero point arrangement tentatively determined by the zero point control unit 103 (step S303). The arithmetic processing unit 105 determines whether or not the derived reception quality estimated value is equal to or higher than the specified threshold value (step S304). When the derived reception quality estimate is equal to or higher than the specified threshold value (step S304: Yes), the arithmetic processing unit 105 determines the channel arrangement and the zero point arrangement (step S310). In the first embodiment, the arithmetic processing unit 105 independently determines the zero point arrangement for each beam, but in the present embodiment, since it is necessary to consider the influence on other beams, the arithmetic processing unit 105 needs to consider the influence on other beams at the same time. think about. When the arithmetic processing unit 105 determines the zero point arrangement to be used by the transmitting station 300, the arithmetic processing unit 105 notifies the zero point control unit 103 to that effect. The zero point control unit 103 outputs the zero point arrangement information indicating the tentatively determined zero point arrangement to the filter control unit 102.

The filter control unit 102 derives the coefficient of the filter based on the zero point arrangement information and outputs the filter information to the control information transmission / reception unit 101. The control information transmission / reception unit 101 transmits the channel arrangement information acquired from the frequency control unit 104 and the filter information acquired from the filter control unit 102 to the transmission station 300 as control information (step S311). If no channel arrangement candidate remains (step S308: No), the arithmetic processing unit 105 does not determine the channel arrangement and the zero point arrangement, and the control station 100 ends the operation of the flowchart shown in FIG. In this way, in the control station 100, the arithmetic processing unit 105 determines the channel arrangement and the zero point arrangement so that the reception quality estimated value becomes equal to or more than the defined threshold value. In the present embodiment, the frequency control unit 104 changes the channel arrangement and generates channel arrangement information each time the change is made. The arithmetic processing unit 105 determines the channel arrangement used by the transmitting station 300 based on the reception quality estimated value. When the derived reception quality estimated value is less than the specified threshold value, the arithmetic processing unit 105 causes the zero point control unit 103 to change the zero point arrangement so that the received quality estimated value is equal to or higher than the specified threshold value, and the frequency control unit 105. Let 104 change the channel arrangement.

Next, the operation of the transmitting station 300 that has received the control information from the control station 100 will be described. FIG. 17 is a flowchart showing the operation of the transmitting station 300 according to the second embodiment. In the transmitting station 300, the control information transmission / reception unit 311 receives the control information from the control station 100 (step S401). The control information transmission / reception unit 311 outputs control information to the transmission frequency conversion unit 341 of the corresponding beam. The transmission frequency conversion unit 341 sets the coefficient of the filter based on the filter information included in the control information (step S402). Further, the control information transmission / reception unit 311 outputs control information to the channelizer 331. The channelizer 331 sets the channel to be used for each beam input to the channelizer 331 based on the channel arrangement information included in the control information (step S403).

As described above, according to the present embodiment, in the data transmission system 500, the control station 100 sets the channel arrangement and the zero point arrangement of the transmission station 300 that performs delta-sigma modulation, and adjusts the notch position. bottom. As a result, the data transmission system 500 can further improve the reception quality at the receiving station 200 that receives the signal from the transmitting station 300 as compared with the first embodiment.

The configuration shown in the above embodiments is an example, and can be combined with another known technique, can be combined with each other, and does not deviate from the gist. It is also possible to omit or change a part of the configuration.

100 control station, 101, 311 control information transmission / reception unit, 102 filter control unit, 103 zero point control unit, 104 frequency control unit, 105 arithmetic processing unit, 200 reception station, 300 transmission station, 301 relay unit, 302 transmission unit, 320, 342 antenna, 321 reception frequency converter, 331 channelizer, 341 transmission frequency converter, 351 and 371 filters, 361 quantizer, 381 adder, 500 data transmission system.

Claims (13)

In a data transmission system in which a transmitting station that performs delta-sigma modulation transmits data to a receiving station, it is a control station that controls the operation of the transmitting station.
A frequency control unit that generates channel placement information that indicates the allocation of channels, which are units of frequency division, to each beam.
A zero point control unit that changes the zero point arrangement of the delta-sigma modulation and generates zero point arrangement information indicating the zero point arrangement each time the change is made.
An arithmetic processing unit that determines the zero point arrangement used by the transmitting station by using the channel arrangement information and the zero point arrangement information.
A control station characterized by being equipped with. The arithmetic processing unit derives a reception quality estimated value at the receiving station using the channel arrangement information and the zero point arrangement information, and determines the zero point arrangement used by the transmitting station based on the reception quality estimated value.
The control station according to claim 1. When the derived reception quality estimated value is less than the specified threshold value, the arithmetic processing unit causes the zero point control unit to change the zero point arrangement so that the received quality estimated value becomes equal to or more than the specified threshold value.
The control station according to claim 2. The frequency control unit changes the channel arrangement, and each time the change is made, the frequency control unit generates the channel arrangement information.
The arithmetic processing unit determines the channel arrangement used by the transmitting station based on the received quality estimate.
The control station according to claim 2 or 3. When the derived reception quality estimate is less than the specified threshold value, the arithmetic processing unit causes the frequency control unit to change the channel arrangement so that the reception quality estimate value is equal to or more than the specified threshold value.
The control station according to claim 4. The reception quality estimate is defined by at least one of the average Signal to Interference plus Noise Ratio of the transmitted signal, the satisfaction with the requirement, and the amount of interference.
The control station according to any one of claims 2 to 5, wherein the control station is characterized in that. In a data transmission system in which a transmitting station performing delta-sigma modulation transmits data to a receiving station, the transmitting station whose operation is controlled by the control station.
A control information transmission / reception unit that receives control information from the control station,
A transmission frequency converter that changes the filter coefficient of the delta-sigma modulator based on the control information,
A transmitting station characterized by being equipped with. The control station according to any one of claims 1 to 6.
The transmitting station according to claim 7 and
A data transmission system characterized by being equipped with. A control circuit for controlling a control station that controls the operation of the transmitting station in a data transmission system in which a transmitting station that performs delta-sigma modulation transmits data to a receiving station.
Generates channel placement information that indicates the allocation of channels to each beam, which is a unit of frequency division.
The zero arrangement of the delta-sigma modulation is changed, and each time the change is made, zero point arrangement information indicating the zero arrangement is generated.
The zero point arrangement used by the transmitting station is determined by using the channel arrangement information and the zero point arrangement information.
A control circuit characterized by having a control station carry out the above. A control circuit for controlling a transmitting station whose operation is controlled by a control station in a data transmission system in which a transmitting station performing delta-sigma modulation transmits data to a receiving station.
Receive control information from the control station,
Based on the control information, the filter coefficient of the delta-sigma modulator is changed.
A control circuit characterized by having a transmitting station carry out the above. A storage medium that stores a program for controlling a control station that controls the operation of the transmitting station in a data transmission system in which a transmitting station that performs delta-sigma modulation transmits data to a receiving station.
The program
Generates channel placement information that indicates the allocation of channels to each beam, which is a unit of frequency division.
The zero arrangement of the delta-sigma modulation is changed, and each time the change is made, zero point arrangement information indicating the zero arrangement is generated.
The zero point arrangement used by the transmitting station is determined by using the channel arrangement information and the zero point arrangement information.
A storage medium characterized by having a control station carry out the above. In a data transmission system in which a transmitting station that performs delta-sigma modulation transmits data to a receiving station, it is a storage medium that stores a program for controlling the transmitting station whose operation is controlled by the control station.
The program
Receive control information from the control station,
Based on the control information, the filter coefficient of the delta-sigma modulator is changed.
A storage medium characterized by having a transmitting station carry out the above. In a data transmission system in which a transmitting station performing delta-sigma modulation transmits data to a receiving station, this is a data transmission control method of a control station that controls the operation of the transmitting station.
The first step in which the frequency control unit generates channel arrangement information indicating the allocation of channels, which are units of frequency division, to each beam, and
A second step in which the zero point control unit changes the zero point arrangement of the delta-sigma modulation and generates zero point arrangement information indicating the zero point arrangement each time the change is made.
A third step in which the arithmetic processing unit determines the zero point arrangement used by the transmitting station by using the channel arrangement information and the zero point arrangement information.
A data transmission control method comprising.

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