JP2009278494A - Wireless communication system, and line allocation device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain signal quality and to effectively utilize frequencies in a wireless communication system where terminal stations that perform different polarization processes are mixed. <P>SOLUTION: A line allocation device holds therein: information indicating classes of terminal stations classified on the basis of polarization processing functions of the terminal stations; information indicating allocated lines and classes of terminal stations using the allocated lines; information on a polarization share condition indicating a combination of classes of terminal stations capable of sharing polarization; and information indicating a fixed frequency point, which is a predetermined frequency, inside a frequency band available for a wireless communication system. When a line allocation request signal is received from a terminal station, from among frequency bands, which can be allocated to the terminal station satisfying the polarization share condition for each polarization, a frequency band equal to a bandwidth of a line to be allocated to the terminal station and including a frequency closest to the fixed frequency point is allocated to the terminal station. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a line allocation technique in a radio communication system, and more particularly, a line that enables maintenance of signal quality and effective use of frequency in a radio communication system in which terminal stations that perform different polarization processing are mixed. It relates to allocation technology.

  Based on the line allocation request from the terminal station, the bandwidth of the bandwidth requested by the terminal station is allocated to the terminal station from the unused band within the usable frequency band, that is, the free band, and then the terminal station In a wireless communication system in which a line is released and communication is made free again after communication is completed, it is unavoidable that the distribution of free bandwidth becomes discontinuous. In such a wireless communication system, if there is no continuous free bandwidth wider than the bandwidth required by the terminal station, line allocation cannot be performed even if the total free bandwidth is greater than the required bandwidth, and the frequency of There is a problem that effective use cannot be achieved.

  For this reason, as shown in FIG. 14, Non-Patent Document 1 describes a configuration that uses a continuous band from an available frequency band in order to widen a continuous free band as much as possible. Non-Patent Document 2 describes a configuration for performing rearrangement of allocated frequency bands. More specifically, as shown in FIG. 15A, in the state where lines B and D are assigned to the vertical (V) polarization and lines A and C are assigned to the horizontal (H) polarization, FIG. When the allocation of the line E shown in FIG. 4 is necessary, the V-polarized line B is rearranged to the H-polarized wave, and a new line E is placed in the continuous frequency band of the V-polarized wave. The configuration to be assigned is described.

  Non-Patent Documents 3 and 4 describe polarization beam forming technology for polarization sharing and polarization interference compensation technology, and Non-Patent Document 5 describes the configuration of a multicarrier terminal station. Patent Document 6 describes a method of measuring a deviation in polarization angle.

Paul. Wilson, et al. , "Dynamic Storage Allocation: A Survey and Critical Review", A International Workshop on Memory Management, 1995. “Survey Report on Effective Frequency Utilization Technology Using Variable Bandwidth Control Technology in Satellite Communication”, Radio Industry Association, pp. 22-27 and pp. 75-79, March 2001 Konishi, et al., “Broadband Aeronautical Satellite Communication Antenna”, IEICE Transactions B, J88-B, pp. 1613-1625, 2005 Yamashita, et al. "Variable Polarization Frequency Division Multiplexing (VPFDM) for satellite communications", ICSSC 2007-3244. Tanabe, et al. , "MULTICARRIER / MULTIRITE MODEM USING TIME-DIVISION MULTIIPLE PROCESSING", ICSSC 2002-2069 Yamashita et al., "A Study on Bandwidth Sharing of VPFDM and Existing Systems Using Transmitted Polarization Beamforming", IEICE General Conference, B-3-18, 2007

  In a radio communication system that uses polarization sharing, a radio signal transmitted with a certain terminal station leaks into another polarization of the same frequency as an interfering wave. The terminal stations used will interfere with each other. That is, for example, as shown in FIG. 16, when the terminal station α uses V polarization and the terminal station β uses H polarization of the same frequency band as the terminal station α, the terminal stations α and β Both receive the interference wave shown as the shaded portion in FIG. 16 from the terminal stations using other polarizations, so that the quality of both terminal stations deteriorates. For this reason, it is necessary to reduce the amount of interference.

  Regarding the reduction of the amount of interference, in a wireless communication system in which terminal stations having different polarization adjustment accuracy are mixed, it is necessary to consider the polarization adjustment accuracy in line allocation. For example, as the type of terminal station, there is a terminal station α with high polarization adjustment accuracy and a terminal station β with low polarization adjustment accuracy, and the amount of pre-interference with other polarizations of the terminal station β is large. It is assumed that other terminal stations cannot use a line having a different polarization and different frequency band from the line assigned to the terminal station β. In this case, if there is a line allocation request from the terminal station β in the state shown in FIG. 17, the line cannot be allocated even though there is sufficient free bandwidth.

  Therefore, the present invention provides a wireless communication system, a line assignment method, and a line assignment apparatus that enable maintenance of signal quality and effective use of frequencies in a wireless communication system in which terminal stations that perform different polarization processes are mixed. The purpose is to provide.

According to the wireless communication system of the present invention,
A wireless communication system comprising a plurality of terminal stations that can use two orthogonal polarizations and a line assignment device that assigns a line to the terminal station, each terminal station being classified based on a polarization processing function The line allocation device indicates a combination of the allocated line, information indicating the type of the terminal station that uses the allocated line, and the type of the terminal station that can share polarization. Information on polarization sharing conditions and information indicating a fixed frequency point that is a predetermined frequency within a frequency band that can be used by a wireless communication system are retained. When the request signal is received, the frequency band that can be allocated to the terminal station that satisfies the polarization sharing condition for each polarization is equal to the bandwidth of the line allocated to the terminal station, and A frequency band including a frequency nearest to the serial fixed frequency points, and allocates to the terminal station.

According to another embodiment of the wireless communication system of the present invention,
A wireless communication system comprising a plurality of terminal stations that can use two orthogonal polarizations and a line assignment device that assigns a line to the terminal station, each terminal station being classified based on a polarization processing function The line allocation device indicates a combination of the allocated line, information indicating the type of the terminal station that uses the allocated line, and the type of the terminal station that can share polarization. Information on the polarization sharing condition, and unused frequency bands of each polarization that can be used by the wireless communication system based on the information on the allocated line, both vacant spaces in which both polarizations are unused When the line allocation apparatus receives a line allocation request signal from the terminal station, the terminal that satisfies the polarization sharing condition for each polarization Assign to station A frequency band equal to the bandwidth of the line allocated to the terminal station is selected and allocated to the terminal station, and the frequency band is selected by selecting a frequency band from a free band satisfying the polarization sharing condition. In this case, priority is given to the frequency band from the two free bands that satisfy the polarization sharing condition.

According to the line allocation method in the present invention,
Polarization sharing conditions that indicate the combination of two types of terminal stations that can use two orthogonal polarizations and belong to one of the types classified based on the polarization processing function and the types of terminal stations that can share polarization And a line allocation method in a radio communication system comprising a line allocation apparatus that holds information indicating a fixed frequency point that is a predetermined frequency within a frequency band that can be used by the radio communication system. The terminal station transmitting a line allocation request signal to the line allocation apparatus, and the line allocation apparatus determining a frequency band that can be allocated to the terminal station that satisfies the polarization sharing condition of each polarization; The line allocation device is equal to the bandwidth of the line allocated to the terminal station from the determined frequency band, and is the most equal to the fixed frequency point. A frequency band including the frequency have, characterized in that it comprises a allocated to the terminal station.

According to another embodiment of the line allocation method of the present invention,
Polarization sharing conditions that indicate the combination of two types of terminal stations that can use two orthogonal polarizations and belong to one of the types classified based on the polarization processing function and the types of terminal stations that can share polarization A line allocation method in a wireless communication system comprising a line allocation device that holds the information of: a terminal station transmitting a line allocation request signal to the line allocation device; A step of determining a frequency band that can be allocated to the terminal station that satisfies a polarization sharing condition of polarization, and a line allocation device that selects a frequency band equal to a bandwidth of a line allocated to the terminal station from the determined frequency band And in the selecting step, the frequency band in which the other polarizations are already used is superior to the frequency band in which both polarizations are unused. And selecting by.

  The line assignment apparatus of the present invention is a line assignment apparatus used in the wireless communication system.

Furthermore, according to another embodiment of the present invention,
When the line allocation apparatus can select the same frequency band of both polarizations as the line to be allocated to the terminal station, it is preferable to select the line closer to the allocated line. Also, the amount of interference given to the different polarizations by the terminal station is evaluated in two or more stages, the interference tolerance of the terminal station is evaluated in two or more stages, and the type of terminal station is the amount of interference given to the different polarizations of the terminal station It is also preferable that it is determined based on the evaluation value and the evaluation value of the interference resistance. Furthermore, it is a two-stage evaluation in which the amount of interference given to different polarizations is large and small, and is a two-step evaluation in which the interference tolerance is large and small. The terminal station has a large amount of interference given to different polarizations and has a small interference tolerance The amount of interference given to different polarizations with the first type is small, and the amount of interference given to different polarizations is small with the second type having a small interference tolerance, and the interference tolerance is large. The combinations classified into the third type and capable of polarization sharing are the first type and the third type, the second type and the second type, the second type and the third type, and The third type and the third type are also preferable.

  Give priority to the frequency band of the line assigned to the terminal station as close as possible to the frequency fixed point that is the predetermined frequency position, or to the other polarized waves from the frequency band where the line is already arranged. By allocating to the terminal station, it is possible to make the bands that are vacant in both polarizations as continuous as possible, thereby suppressing the call loss rate and improving the frequency utilization efficiency.

  The best mode for carrying out the present invention will be described in detail below with reference to the drawings. In the following description, a wireless transmission path that is specified by a frequency band and a polarization and used for wireless communication is referred to as a line. The frequency band is a frequency range, and is specified by, for example, a lower limit and an upper limit frequency, a center frequency, a bandwidth, and the like. If only the frequency width is considered and the frequency position is arbitrary, it is simply called a bandwidth. Furthermore, in the following description, linearly polarized waves are used, but circularly polarized waves may be used.

  FIG. 9 is a diagram showing one form of a wireless communication system to which the line allocation method according to the present invention is applied, more specifically a satellite communication system using the satellite 2. In FIG. 9, each terminal station 3 can transmit and receive radio signals of two polarizations orthogonal to each other, in this embodiment, vertical polarization (V) and horizontal polarization (H). When it is necessary to communicate with the terminal station, a line allocation request signal is transmitted to the base station 1 through the control line 4.

  The base station 1 has a line allocation apparatus according to the present invention, and when a line allocation request signal is received, a line allocated to the terminal station 3 that has transmitted the line allocation request signal based on the line allocation method according to the present invention. 5, that is, the polarization and the frequency band are determined, and the determined line 5 is notified to the terminal station 3 that has made a line allocation request by the control line 4.

  Thus, the terminal station 3 that has received the line assignment communicates with the other terminal station 3 or with the base station 1 and the line 5. In the wireless communication system according to the present invention, the terminal station 3 also notifies the base station 1 of the communication end, and the base station 1 releases the allocated line 5 with the reception of the communication end.

  Note that the terminal station 3 transmits the line allocation request signal including the requested bandwidth, and the base station 1 uses a frequency band equal to the requested bandwidth to an unused band within an available frequency band. Select from and assign as a line. The bandwidth requested by the terminal station 3 is an integral multiple of the minimum bandwidth that can be used by each terminal station 3. In a wireless communication system that allocates only a fixed bandwidth, it is not necessary to include the bandwidth in the line allocation request signal.

  In the present invention, the terminal stations 3 are classified into “types” based on the difference in polarization processing. In the following description, the terminal station 3 includes a polarization non-tracking station (hereinafter referred to as a non-tracking station), a polarization tracking station (hereinafter referred to as a tracking station), and an adaptive polarization station (hereinafter referred to as a tracking station). Classified into three types). Here, the non-tracking station is a terminal station 3 that performs transmission and reception of signals in the direction of the polarization axis that is simply adjusted, and has a large amount of pre-interference for a polarization different from the transmission polarization. Further, the tracking station has a function of adjusting the polarization axis of the polarization to be transmitted and received with high accuracy by mechanical drive, and is thus a terminal station 3 with a small pre-interference amount. Note that the non-tracking station and the tracking station do not perform the polarization compensation process on the receiving side, and thus are terminal stations 3 that have low interference tolerance from other terminal stations 3. On the other hand, the adaptive station reduces the amount of pre-interference on the transmitting side by polarization beam forming technology, and reduces the amount of interference from other terminal stations on the receiving side by using polarization interference compensation technology. The terminal station 3 that performs the processing, that is, the terminal station 3 that has a small amount of pre-interference and a large interference tolerance. FIG. 11 shows various characteristics.

  In order to use polarization sharing, that is, a line with a certain polarization and a line with another polarization whose frequency band overlaps with this line at the same time, it is necessary to suppress the influence of interference in each terminal station 3 to a certain level or less. There is. For this reason, in the present invention, a polarization sharing condition indicating a combination that allows polarization sharing is determined in advance according to the combination of types of terminal stations. For example, taking a radio communication system in which the above-described terminal station types are mixed as an example, polarization sharing conditions can be defined as shown in FIG. According to FIG. 12, since the adaptive station has a small amount of pre-interference and a large interference tolerance, the non-tracking station, the tracking station, and the adaptive station can share the polarization. Although the amount is small but the interference tolerance is small, the polarization can be shared with the tracking station or the adaptive station, and the non-tracking station can share the polarization only with the adaptive station because the amount of pre-interference is large. It is supposed to be.

  Hereinafter, the description will be made using the polarization sharing condition shown in FIG. 12, but the polarization processing of each terminal station type, that is, the polarization axis adjustment function on the transmission side and / or the interference tolerance on the reception side in each terminal station The target quality defines whether or not the polarization can be shared among various types is the polarization sharing condition, and the present invention is not limited to the use of the polarization sharing condition shown in FIG. FIG. 13 shows a type A with a large pre-interference amount and a small interference tolerance, a type A with a small pre-interference amount and a small interference tolerance, and a type C with a large pre-interference amount and a large interference tolerance. An example of the polarization sharing condition in the case of using the type D having a small pre-interference amount and a large interference tolerance is shown. In addition, the amount of pre-interference and the interference tolerance are not evaluated in two stages, “Large” and “Small”, but are evaluated in multiple stages according to their capabilities, and the combination of polarization is determined by the combination. good.

  In the following description, as shown in FIG. 10, the frequency band that is not used for both polarizations is referred to as “both free band”, and the frequency band that is not used for only one polarization is referred to as “one free band. ". In order to increase the frequency utilization efficiency and reduce the call loss rate, it is important to perform line allocation so that the frequency bands that are continuously vacant, particularly, both idle bands are as wide as possible.

Hereinafter, a first embodiment of a line allocation method according to the present invention will be described. In this embodiment, a fixed frequency point (FP) is provided in advance in an available band that can be used by the wireless communication system. Note that the FP can be set at an arbitrary position within the use band. In the present embodiment, each terminal station can use only a continuous frequency band line. That is, when the required bandwidth is B (Hz), the frequency band of F (Hz) to F + B (Hz) can be used as a line, but F ₁ (Hz) to F ₁ + B / 2 (Hz) and F It is assumed that a line divided into different frequency bands cannot be used even if the total bandwidth is B (Hz), such as ₂ (Hz) to F ₂ + B / 2 (Hz).

In the present embodiment, when a line allocation request occurs, the base station 1 performs line allocation according to the following procedure.
(Procedure 1-1) A bandwidth that can be allocated to a terminal station that satisfies the polarization sharing condition, that is, an unused frequency band that satisfies the polarization sharing condition and that continues beyond the bandwidth of the line is searched.
(Procedure 1-2) A frequency band including the closest frequency through both polarizations is assigned to the FP in the frequency band obtained in Procedure 1-1 as a line.
(Procedure 1-3) When the same frequency band of both polarizations can be assigned as a line in Procedure 1-2, the polarization closer to the already assigned line is assigned as a line.

  FIG. 1 is a diagram for explaining a line allocation method according to the first embodiment. In the figure, a section between vertical arrows is an available frequency band of the wireless communication system, and this expression is the same in FIGS. 2 to 4 and 7. In the example shown in FIG. 1, FP is set as the lower limit frequency of the usable frequency band, and line allocation requests with the same bandwidth are made in the order of the non-tracking station a, the tracking station b, the tracking station c, and the adaptive station d. Shall.

  First, since a frequency band including FPs of both polarizations can be allocated according to the above procedure in response to a line allocation request of the non-tracking station a, the base station 1 can obtain a V polarization as shown in FIG. Wave line is assigned. In response to the line allocation request of the tracking station b, the frequency band adjacent to the line allocated to the non-tracking station a and the frequency of the H polarization that is the same frequency band from the procedure 1-1 and the procedure 1-2. Although the band is a candidate for the line, the base station 1 assigns a line adjacent to the line already assigned to the non-tracking station a as shown in FIG. Further, in response to the channel allocation request of the tracking station c, the base station 1 allocates an H-polarized channel having the same frequency band as the channel allocated to the tracking station b, as shown in FIG. . Further, in response to the channel allocation request of the adaptive station d, the base station 1 allocates an H-polarized channel having the same frequency band as the channel allocated to the non-tracking station a as shown in FIG. Become.

  FIG. 2 shows that the FP is set to the upper limit frequency of the usable frequency band, and the line allocation request is made in the order of the non-tracking station a, the tracking station b, the adaptive station c, the non-tracking station d, the adaptive station e, and the non-tracking station f. 3 shows a line allocation situation in the case where there is an error, and FIG. 3 shows that the FP is set to the center frequency of the usable frequency band, the non-tracking station a, the adaptive station b, the tracking station c, the adaptive station d, the non-tracking station e, The line allocation situation when there is a line allocation request in the order of the non-tracking station f is shown.

  As shown in FIGS. 1 to 3, the line allocation method according to the present invention ensures a wide and continuous free bandwidth in an area separated from the FP on the frequency axis in any case. Note that the procedure 3 is for widening a continuous free band as much as possible.

Next, a second embodiment of the line allocation method according to the present invention will be described. Also in this embodiment, each terminal station can use only a continuous frequency band line. In the present embodiment, when a line allocation request is generated, the base station 1 performs line allocation according to the following procedure.
(Procedure 2-1) Search for a band that can be allocated to a terminal station that satisfies the polarization sharing condition, that is, an unused frequency band that satisfies the polarization sharing condition and continues beyond the bandwidth of the line.
(Procedure 2-2) Of the frequency bands obtained in Procedure 2-1, if the narrowest free band is not available, if there is no free band, the frequency band equal to the requested bandwidth is connected from the narrowest free band. Assign as.

  FIG. 4 is a diagram for explaining a line allocation method according to the second embodiment. After the communication of the adaptive station i, the tracking station g, and the adaptive station k is completed from the line assignment state shown in FIG. 4A, and the state shown in FIG. 4B is reached, the tracking station o and the non-tracking station p When the line allocation request is made in the order of the adaptive station q, the line is allocated as shown in FIG. 4C by the above procedures 2-1 and 2-2. In the present embodiment, both wide free bands are secured by preferentially allocating from one free band. When there are a plurality of lines that satisfy the conditions of procedure 2-1 and procedure 2-2, it is preferable to allocate a line including the closest frequency to both FPs through both polarizations.

  The methods described in the first embodiment, the second embodiment, and Non-Patent Document 1 were respectively simulated, and the call loss rate and the frequency utilization efficiency when the total number of terminal stations was changed were obtained. Note that the numbers of terminal stations 3 are the same, that is, for example, when the total number of terminal stations 3 is 90, the number of non-tracking stations, tracking stations, and adaptive stations is 30. Also, the minimum bandwidth that can be used by the terminal station is one frequency slot, the frequency band that can be used by the wireless communication system is 360 frequency slots, the bandwidth required by the terminal station is four frequency slots, and the line request intervals of the terminal stations are averaged. The communication time of the terminal station was 5 minutes on average, and the line request by the terminal station and the line opening accompanying the end of communication of the terminal station were repeated for 24 hours. FIG. 5 shows the frequency utilization efficiency, and FIG. 6 shows the result of the call loss rate simulation. From FIG. 5 and FIG. 6, it can be seen that the call loss rate is reduced and the frequency utilization efficiency is improved in the present invention as compared with the prior art.

  The terminal station 3 is not limited to a single carrier type that can use only a continuous frequency band line, but also divides the bandwidth required for the line into a plurality of continuous bands, A multi-carrier type that can be transmitted and received as a line can also be used. For example, it is assumed that the multi-carrier type adaptive station g requests a bandwidth line shown in FIG. 7B in the line assignment state shown in FIG. Since each carrier can be allocated less than the bandwidth of the line, the base station 1 can allocate all unused frequency bands in FIG. 7 (a) to the polarization station g while satisfying the polarization sharing condition. It can be determined as a frequency band. Therefore, in this frequency band, the same frequency band as the H-polarized non-tracking station c including the frequency closest to the FP is allocated to the first carrier. Subsequently, with the first carrier assigned, the base station 1 again determines a frequency band that satisfies the polarization sharing condition and can be assigned to the adaptive station g. At this time, the bandwidth used as a reference for determination is obtained by subtracting the bandwidth allocated to the first carrier from the bandwidth of the line. From FIG. 7A, it can be determined that all unused frequency bands satisfy the polarization sharing condition and can be allocated to the adaptive station g, and therefore, no tracking of H polarization including the frequency closest to the FP. The same frequency band as that of station f is assigned to the second carrier. Therefore, the line allocation status is as shown in FIG. As a result, a wider open bandwidth can be secured, the call loss rate can be lowered, and the frequency utilization efficiency can be improved.

Therefore, when single carrier type and multicarrier type terminal stations coexist, the first embodiment is extended as follows.
(Procedure 1-0) It is determined whether the terminal station making the line request is a single carrier type or a multi carrier type. In the case of a single carrier type, steps 1-1 to 1-3 are performed.
(Procedure 1-4) In the case of the multi-carrier type, a band that can be allocated to a terminal station that satisfies the polarization sharing condition, that is, an unused continuous frequency band that satisfies the polarization sharing condition is searched.
(Procedure 1-5) The frequency band including the frequency closest to the FP through both polarizations in the frequency band obtained in Procedure 1-4 is assigned to the first carrier. If the bandwidth is continuous beyond the bandwidth of the line, only the frequency band equal to the bandwidth of the line is allocated and the process is terminated.
(Procedure 1-6) When the total allocated bandwidth is less than the bandwidth of the line, the polarization and the allocation to the second and subsequent carriers are performed in the same manner as in Procedure 1-4 and Procedure 1-5. Determine the frequency band. For the last carrier that can be divided, the polarization and frequency band are determined by procedures 1-1 to 1-3.

Similarly, when the single carrier type and multicarrier type terminal stations coexist, the second embodiment is extended as follows.
(Procedure 2-0) It is determined whether the terminal station requesting the line is a single carrier type or a multicarrier type. In the case of a single carrier type, steps 2-1 to 2-2 are performed.
(Procedure 2-3) In the case of the multi-carrier type, a band that can be allocated to a terminal station that satisfies the polarization sharing condition, that is, an unused continuous frequency band that satisfies the polarization sharing condition is searched.
(Procedure 2-4) Of the frequency bands obtained in Procedure 2-3, if the narrowest free band is not present, and there is no free single band, the narrowest free band is assigned to the first carrier. If the bandwidth is continuous beyond the bandwidth of the line, only the frequency band equal to the bandwidth of the line is allocated and the process is terminated.
(Procedure 2-5) The polarization and frequency band allocated to the second and subsequent carriers are determined by the same method as in Procedure 2-3 and Procedure 2-4 until the total allocated bandwidth reaches the bandwidth of the line. To do. For the last carrier that can be divided, the polarization and frequency band are determined by procedures 2-1 to 2-2.

  FIG. 8 is a block diagram of a line allocation apparatus according to the present invention that is installed in the base station 1. The line management database holds information for identifying the terminal station 3 for all terminal stations 3, that is, information for identifying the terminal station ID and its type and function. Here, the function is the minimum bandwidth that can be allocated, the maximum number of carriers that can be used in the case of the multicarrier type, the single carrier type, or the multicarrier type. Further, the line management database holds information about the assigned lines and information about the type of the terminal station 3 that uses each assigned line. When the access control unit receives a line allocation request signal from the terminal station 3 via the adaptive polarization compatible modem, the access control unit notifies the line allocation algorithm unit of the ID of the terminal station 3 that made the line allocation request and the requested bandwidth. The line allocation algorithm unit recognizes the current line allocation status and the type and function of the terminal station making the line allocation request from the line management database, performs line allocation according to the above-described procedure, and accesses the allocated line. The access control unit notifies the terminal station 3 that has made the line allocation request via the adaptive polarization modem. Further, the line management database is updated according to line allocation and release.

  Note that in the case of a non-tracking station, the polarization shift differs depending on the installation situation, and in some cases, the polarization shift is small, and thus there is a low pre-interference amount. A signal with a pre-interference amount of a certain value or less can be handled in the same way as a tracking station, for example. Therefore, preferably, a signal for measuring a polarization angle is given to a line allocation request signal, and the access control unit Based on the signal for measuring the polarization angle, the polarization deviation of the non-tracking station that requested the line allocation is measured. The access control unit notifies this polarization deviation to the line allocation algorithm unit, and if the polarization deviation is less than a certain amount, the line allocation algorithm unit treats it as equivalent to the tracking station and allocates the line. Do.

  As described above, the line allocation method according to the present invention makes it possible to suppress the call loss rate and improve the frequency utilization efficiency even when terminal stations having different polarization processes coexist.

It is a figure explaining the line allocation method by this invention when a fixed frequency point is set to a minimum frequency. It is a figure explaining the line allocation method by this invention when a fixed frequency point is set to an upper limit frequency. It is a figure explaining the line | wire allocation method by this invention when a fixed frequency point is set to a center frequency. It is a figure explaining the line allocation method by 2nd Embodiment of this invention. It is a figure which shows the simulation result of frequency utilization efficiency. It is a figure which shows the simulation result of a call loss rate. It is a figure explaining application to a multicarrier type terminal station. It is a block diagram of the line allocation apparatus by this invention mounted in a base station. It is a figure which shows one form of the radio | wireless communications system to which the line allocation method by this invention is applied. It is a figure explaining both free bands and one free band. It is a figure which shows the characteristic of the classification of a terminal station. It is a figure which shows the example of polarization sharing conditions. It is a figure which shows the other example of polarization sharing conditions. It is a figure which shows the line allocation by a prior art. It is a figure which shows the other form of the line allocation by a prior art. It is a figure explaining generation | occurrence | production of the interference at the time of polarization sharing. It is a figure explaining a problem when the terminal from which polarization adjustment capability differs is mixed.

Explanation of symbols

1 base station 2 satellite 3 terminal station 4 control line 5 line

Claims (13)

A plurality of terminal stations that can use two orthogonal polarizations;
A line assignment device for assigning a line to a terminal station;
A wireless communication system comprising:
Each terminal station belongs to one of a plurality of types classified based on the polarization processing function,
The line allocation device includes information indicating an allocated line and a type of a terminal station that uses the allocated line, information on a polarization sharing condition indicating a combination of types of terminal stations that can share polarization, and wireless In a frequency band that can be used by the communication system, it holds information indicating a fixed frequency point that is a predetermined frequency,
The line allocation device, when receiving a line allocation request signal from a terminal station, is equal to the bandwidth of the line allocated to the terminal station from the frequency band that can be allocated to the terminal station that satisfies the polarization sharing condition of each polarization, And assigning a frequency band including a frequency closest to the fixed frequency point to the terminal station,
Wireless communication system. The line assignment device selects the one closer to the assigned line when the same frequency band of both polarizations can be selected as the line assigned to the terminal station.
The wireless communication system according to claim 1. A plurality of terminal stations that can use two orthogonal polarizations;
A line assignment device for assigning a line to a terminal station;
A wireless communication system comprising:
Each terminal station belongs to one of a plurality of types classified based on the polarization processing function,
The line allocation device holds information indicating the allocated line and the type of the terminal station using the allocated line, and information on the polarization sharing condition indicating the combination of the types of terminal stations that can share the polarization. And the unused frequency band of each polarization that can be used by the wireless communication system based on the information about the allocated line, the two free bands that are not used for both polarizations, and only one of the polarizations. Classify it as a free band that is unused,
When a line allocation apparatus receives a line allocation request signal from a terminal station, a frequency equal to the bandwidth of the line allocated to the terminal station from a frequency band that can be allocated to the terminal station that satisfies the polarization sharing condition of each polarization. Select a bandwidth and assign it to the terminal station,
The selection of the frequency band gives priority to the frequency band from one free band satisfying the polarization sharing condition over the frequency band from both free bands satisfying the polarization sharing condition,
Wireless communication system. Evaluate the amount of interference that the terminal station gives to different polarizations in two or more stages, evaluate the interference tolerance of the terminal station in two or more stages,
The type of the terminal station is determined based on the evaluation value of the amount of interference given to different polarizations of the terminal station and the evaluation value of the interference tolerance.
The radio | wireless communications system of any one of Claim 1 to 3. The amount of interference given to different polarizations is a two-stage evaluation with large and small, and the interference tolerance is a two-stage evaluation with large and small,
The terminal station has a large amount of interference given to different polarizations and a first type having a small interference tolerance, and a second type having a small amount of interference given to different polarizations and a small interference tolerance. And is classified into a third type in which the amount of interference given to different polarizations is small and the interference tolerance is large,
The combinations that can share polarization are the first type and the third type, the second type and the second type, the second type and the third type, and the third type and the third type. Is,
The wireless communication system according to claim 4. A line assignment apparatus for assigning lines to a plurality of terminal stations that can use two orthogonal polarizations,
Information indicating the type of terminal station classified based on the polarization processing function of the terminal station,
Information indicating the allocated line and the type of terminal station using the allocated line;
Information about polarization sharing conditions indicating combinations of types of terminal stations that can share polarization;
Information indicating a fixed frequency point that is a predetermined frequency in a frequency band that can be used by the wireless communication system;
Holding
When a line allocation request signal is received from a terminal station, the fixed frequency is equal to the bandwidth of the line allocated to the terminal station, from the frequency band that can be allocated to the terminal station that satisfies the polarization sharing condition of each polarization. A frequency band including a frequency closest to the point is allocated to the terminal station;
Line assignment device. If the same frequency band of both polarizations can be selected as the line assigned to the terminal station, select the one closer to the assigned line.
The line assignment apparatus according to claim 6. A line assignment apparatus for assigning lines to a plurality of terminal stations that can use two orthogonal polarizations,
Information indicating the type of terminal station classified based on the polarization processing function of the terminal station,
Information indicating the allocated line and the type of terminal station using the allocated line;
Information about polarization sharing conditions indicating combinations of types of terminal stations that can share polarization;
Holding
Based on information about the allocated line, the unused frequency band of each polarization that can be used by the radio communication system for the terminal station, both free bands that are unused for both polarizations, and only one of the polarizations are not used. Classify it into one free band that is used,
When receiving a line allocation request signal from a terminal station, select a frequency band equal to the bandwidth of the line to be allocated to the terminal station from frequency bands that can be allocated to the terminal station that satisfies the polarization sharing condition for each polarization. Assigned to the terminal station,
The selection of the frequency band gives priority to the frequency band from one free band satisfying the polarization sharing condition over the frequency band from both free bands satisfying the polarization sharing condition,
Line assignment device. The amount of interference that the terminal station gives to different polarizations is evaluated in two levels, and the interference tolerance of the terminal station is determined in two levels.
The terminal station has a large amount of interference given to different polarizations and a first type having a small interference tolerance, and a second type having a small amount of interference given to different polarizations and a small interference tolerance. And is classified into a third type in which the amount of interference given to different polarizations is small and the interference tolerance is large,
The combinations that can share polarization are the first type and the third type, the second type and the second type, the second type and the third type, and the third type and the third type. Is,
The line assignment device according to claim 6. A plurality of terminal stations that can use two polarizations orthogonal to each other and belong to any type classified based on the polarization processing function;
Information on polarization sharing conditions indicating combinations of types of terminal stations that can share polarization, and information indicating fixed frequency points that are predetermined frequencies within the frequency band that can be used by the wireless communication system are retained. A line allocation device,
A line allocation method in a wireless communication system comprising:
A terminal station transmitting a line allocation request signal to a line allocation device;
A step in which the line allocation device determines a frequency band that can be allocated to the terminal station that satisfies the polarization sharing condition of each polarization;
The line allocation device allocates a frequency band including a frequency that is equal to the bandwidth of the line allocated to the terminal station from the determined frequency band and includes the frequency closest to the fixed frequency point to the terminal station.
Method. The line assignment device selects the one closer to the assigned line when the same frequency band of both polarizations can be selected as the line assigned to the terminal station.
The method of claim 10. A plurality of terminal stations that can use two polarizations orthogonal to each other and belong to any type classified based on the polarization processing function;
A line allocation device that holds information about polarization sharing conditions indicating combinations of types of terminal stations that can share polarization;
A line allocation method in a wireless communication system comprising:
A terminal station transmitting a line allocation request signal to a line allocation device;
A step in which the line allocation device determines a frequency band that can be allocated to the terminal station that satisfies the polarization sharing condition of each polarization;
A step of selecting a frequency band equal to a bandwidth of a line to be allocated to the terminal station from the determined frequency band;
Contains
In the selecting step, a method of selecting a frequency band in which other polarizations are already used in preference to a frequency band in which both polarizations are not used. The amount of interference that the terminal station gives to different polarizations is evaluated in two levels, and the interference tolerance of the terminal station is determined in two levels.
The terminal station has a large amount of interference given to different polarizations and a first type having a small interference tolerance, and a second type having a small amount of interference given to different polarizations and a small interference tolerance. And is classified into a third type in which the amount of interference given to different polarizations is small and the interference tolerance is large,
The combinations that can share polarization are the first type and the third type, the second type and the second type, the second type and the third type, and the third type and the third type. Is,
The method according to any one of claims 10 to 12.

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