RU2223602C1 - Radio communications process - Google Patents

Abstract

FIELD: communications engineering; mobile communication systems. SUBSTANCE: frequencies allocated for each cell are intentionally grouped, each group having different frequencies; transceivers for each group of frequencies are covered by nesting areas with quasi-like noncrossing circuits one into other. Subscriber terminals are given access to radio links first of all with priority to those of frequency group covering innermost area of cell and if they are inaccessible, that is, if subscriber terminals are beyond this area or they are in this area but radio links of this group are completely busy, these subscriber terminals are sequentially, and with priority too, given access to radio links of this frequency group with numbers reduced by one. EFFECT: enhanced capacity, saved frequency resource, reduced system noise, provision for electrical mobile communications. 4 cl, 1 dwg

Description

 The invention relates to the field of communication, and more particularly to methods of radio communication in a communication system based on the principle of frequency reuse with multiple access.

 The growing number of mobile operators and subscribers aggravates the problem of rational use of the frequency resource, and this requires the development of new ways to increase the frequency reuse efficiency.

 The invention allows to increase the capacity of any communication system for a given number of frequency bands allocated for operation of the system or to provide a given system capacity with a smaller number of frequency bands, i.e. save frequency resource, improve communication quality and increase the overall technical and economic efficiency of the system, taking into account all components that affect its technical performance and overall cost.

 The claimed invention relates to a cellular communication system built in the form of a set of cells covering the served territory. Simplistically, we represent the cell in the form of a hexagon, in the center of which there is a BS serving all subscriber terminals (AT) within its cell. When AT moves from one cell to another, its service is transferred from one BS to another. All BS systems are locked to at least one switching center (CC), which controls the entire system and accesses other communication systems. General control over the operation of the Central Committee and the system as a whole is carried out from the central controller, which is part of the Central Committee and has powerful mathematical software, including a reprogrammable part.

 The real contours (boundaries) of the cells have the form of irregular curves, depending on the propagation and attenuation of the radio waves, and are not clearly defined, the position of the BS also only approximately coincides with the center of the cell. To clarify the essence of the invention, we consider a simplified cellular communication scheme shown in the drawing.

 The principle of frequency reuse is the basic principle of a cellular communication system, which allows to significantly increase the capacity of the system and consists in using different frequency bands in close to one another cells and in repeating them through several cells.

 In the practice of cellular communication, three main methods of multiple access are used - sharing a limited portion of the frequency spectrum by many users: with frequency, time and code separation of communication channels (for example, RF patent, CL N 04 V 7/26, 2104615). Frequency hopping is also used (RF patent, class., 2119255).

For any multiple access, the capacity of the system with the reuse of frequency bands is increased in several main ways:
1) Move to digital information processing and a more advanced access method - from frequency to time and code.

 2) They increase the frequency repeatability, decreasing the service areas of individual BSs (cell fragmentation) and increasing their density in areas with heavy traffic. This is achieved by reducing the radiation power of both BS and AT, lowering the antenna suspension height and increasing the angle of their radiation pattern (M.V. Ratynsky. Fundamentals of cellular communications. M: Radio and communications, 2000, p. 82; Technologies and means Communications, 2002, 2, p. 40).

 3) To reduce the flow of service flows caused by fragmentation, it is proposed to use multilevel systems for building a network with services in macro cells of fast moving ATs, and in microcells - slow moving ATs. With low traffic, the cells are not crushed, but enlarged.

 4) Apply multi-sector BS (3, 6, 9, 12 sectors) using directional antennas in the sectors (RF patent N 04 V 7/26, 2172072).

 5) Occasionally, adaptive channel assignment is used in the frequency and time division of channels. In this case, the frequency resource is not allocated in a predetermined way between the cells of the cluster, but all or partially is at the operational disposal of the Central Committee, which allocates them for use by the base station as calls arrive, i.e. in accordance with real traffic, but subject to the necessary territorial-frequency separation (for example, M.V. Ratynsky, cit., p. 83; RF patent, class N 04 B 7/26, 2154901).

 6) Expand the allocated frequency bands, but this is a little useful way.

 To increase the noise immunity of the system, base stations with the same frequency bands are removed from each other by a distance that provides a given level of co-channel, intra-system interference (M.V. Ratynsky. Fundamentals of Cellular Communication. M., Radio and Communications, 2000, section 2.4.2). There is a method of increasing noise immunity, in which active transponders and ATs with automatic adjustment of signal transmission power, located near an alien interfering BS, receive and transmit signals re-emitted by the transponders, set the frequency range on the BS, which create mutual interference and are interfering with each other which coincides with the operating frequency range AT, respectively, from its own and to its BS (RF patent, class., the same, 2161866).

 Known methods of radio communication are aimed at increasing capacity and reducing intra-system interference of communication systems. However, the speed of development of cellular communications and the investment in its creation and operation are so great that constant further development, improvement, and the search for additional opportunities to increase the technical and economic efficiency of communication systems are required.

As a prototype, the well-known method of radio communication (M.V. Ratynsky. Fundamentals of cellular communication. M.: Radio and communication, 2000, pp. 20-24, 48-54, 65) in a communication system based on the principle of frequency reuse, was selected. constructed in the form of N cells with a base station in each and cell areas S _{0, i} , where i varies from 1 to N, covering the entire served territory, providing radio communication to the subscriber terminals located within the cell with its base station, functional connection all base stations with a common switching center and handover by the switching center from one base station to another when moving subscriber terminals from one cell to another, in which the transceiver devices of the i-th base station and, accordingly, subscriber terminals located within the i-th cell, on Mi radio channels from the allotted for the operation of the communication system of the frequency bands, radio signals are transmitted and received, together covering the entire area of the i-th cell, repeating the required number of frequency bands used in the i-th cell, after several cells according to the scheme provides the desired cochannel electromagnetic compatibility, carrying means allocating radio access user terminals to specify the order of the radio channels.

 The disadvantage of the prototype compared with the claimed method is that it does not provide additional opportunities to increase the capacity and reduce the intra-system interference of communication systems, save frequency resource and therefore does not allow to increase the technical and economic efficiency of the communication system.

A radio communication method is proposed in a communication system based on the principle of frequency reuse, constructed in the form of N cells with a base station in each and cell areas S _{0, i} , where i varies from 1 to N, covering the entire served territory, providing radio communication subscriber terminals located within the cell with their base station, the functional connection of all base stations with a common switching center and the transfer of service by the switching center from one base station to another when moving AT from one cell to another, in which the transceiver devices of the i-th base station and, correspondingly, AT, located within the i-th cell, transmit and receive radio signals on Mi radio channels from the frequency bands assigned to the communication system, covering the entire area i-th cell, with the repetition of the required number of frequency bands used in the i-th cell, through several cells according to the scheme providing the required channel electromagnetic compatibility, providing access to radio channels by transmitter terminals to radio channels in a predetermined order, characterized in that, deliberately in each i-th cell, the transceiver devices of their base station are divided into j-th groups, where j varies from 0 to Ki, and Ki may be unequal for different i-cells transmit and receive radio signals over radio channels from the j-th groups of frequency bands that do not contain the same frequency bands allocated from the frequency bands allocated for the communication system, together covering the i-th cell and the j-th zone embedded in the radio coverage loop i-th cells and one into another, with contours quasi-similar to the contour of the radio coverage of the i-th cell, without intersecting with each other and with the contours of the radio coverage of other cells adjacent to the i-th cell, and the radio communication signals over radio channels from j-th groups of frequency bands in the aggregate cover only the jth zones of the i-th cell, with areas S _{j, i} satisfying the condition S _{ki, i} <... <S _{j, i} <... <S _{2, i} <S _{1, i} <S _{0 , i,} and the access user terminals to the radio channel allocation means perform radio given order, but with a priority to the first radio channels allocated c pn of frequency bands with the largest number j equal to Ki, and only when they are unavailable in cases where the subscriber terminals are in the i-th cell outside the radio coverage zone with the highest number or in this zone, but with fully occupied radio channels of the selected group of frequency bands with the highest number, sequentially, also with priority, access to the radio channels of the allocated groups of frequency bands with unit numbers j reduced by one, up to the radio channels from the group of frequency bands allocated to provide the entire radio coverage of the entire area di of the i-th cell S _{0, i} , while reusing the required number of frequency bands from the j-th group used in the i-th cell is performed in each other cell or through several cells according to the schemes that are not necessarily identical for each j-th group providing the required confocal electromagnetic compatibility.

Also, in each i-th cell, the j-th group of transceivers of their base station transmit and receive radio signals over radio channels from the j-th group of frequency bands corresponding to the j-th radio coverage area, in the amount of M _{j, i} frequency bands close to the whole parts Mi • (S _{j, i} -S _{j + 1, i} ) / S _{0, i} , where j varies from 0 to Ki, and the areas S _{j, i are} given, a S _{Ki + 1, i} ≡ 0 and the condition M _{0, i} + M _{1, i} + ... + M _{j, i} + ... + M _{Ki, i} = Mi.

In addition, in each i-th cell, the j-th group of transceivers of their base station transmit and receive radio signals over radio channels from the j-th group of frequency bands corresponding to the j-th radio coverage area with an area S _{j, i} equal to (S _{j -1, i} -S _{0, i} • M _{j-1, i} / Mi), where j varies from 1 to Ki, and M _{j, i are} given for all j from 0 to Ki, and M _{0, i} + M _{1 , i} + ... + M _{j, i} + ... + MK _{i, i} = Mi.

 And, finally, in each i-th cell, the j-th group of transceivers of their base station with possibly large numbers j transmit and receive radio signals over radio channels from the j-th group of frequency bands corresponding to the j-th radio coverage zone most adjacent to the bands frequencies occupied by radio-electronic means of other communication systems located in the vicinity of the i-th cell.

 The proposed method of radio communication increases the technical and economic efficiency of the communication system due to the reception and transmission of radio signals by transmitting and receiving devices (PPU) of their BS according to the new algorithm and making AT access to the radio channels in the specified order, but with a new construction of access priority. This allows you to increase capacity, reduce intra-system interference, provide electromagnetic compatibility with electronic means of other communication systems, save frequency resource and, as a result, reduce the cost of cellular communication systems.

 Below the invention is described in more detail with reference to the drawing, schematically illustrating the implementation of the claimed method.

 The method extends to both existing and designed cellular communication systems of various standards and can be applied in conjunction with almost any known methods of increasing the efficiency of using a frequency resource, supplementing and developing them and giving, as shown below, a significant economic effect.

 The proposal method is as follows.

The method extends to a communication system built in the form of N cells with BS located conditionally in the center of each of them. The area of the ith cell is S _{0, i} , where i varies from 1 to N. The BS provides radio communications to all ATs located within the cell. All BSs are functionally connected to a common CC, which transfers service from one BS to another when AT moves from one cell to another.

 Transceivers of the i-th base station and, accordingly, subscriber terminals located within the i-th cell transmit and receive radio signals on Mi radio channels from the frequency bands allocated for the operation of the communication system, together covering the entire area of the i-th cell. The required number of frequency bands used in the ith cell is repeated through several cells according to the scheme providing the required co-channel electromagnetic compatibility, as is customary in communication systems based on the principle of frequency reuse. AT access to the radio channels is carried out by the means of allocating radio channels specified in a particular communication system.

 To achieve the technical result of the invention, the following actions are taken.

In each i-th cell, PUFs of their BS are divided into j-th groups, where j varies from 0 to Ki, and Ki may be unequal for different i-cells. Each j-th group of control rooms intentionally transmits and receives radio communication signals via radio channels only from the j-th group of frequency bands allocated from the assigned frequency band communication system, in combination with other frequency bands, covering the j-th zone of the i-th cell. Moreover, unequal frequency bands are used in all j-th groups. All the jth radio coverage zones are nested in the radio coverage loop of the i-th cell and one into the other and have contours that are quasi-similar to the radio coverage loop covering the entire i-th cell. The contours of the jth radio coverage zones should not intersect with each other and with the radio coverage contours of other cells adjacent to the i-th cell. The areas of the jth radio coverage zones S _{j, i of} each cell satisfy the condition S _{ki, i} <... <S _{j, i} <... <S _{2, i} <S _{1, j} <S _{0, i} , i.e. . the inner zone has the highest number, and the outer one is the zero number. In this case, it is crucial that radio communication signals from radio channels from the j-th group of frequency bands collectively cover only the j-th zone of the i-th cell.

 The required number of frequency bands from the jth group used in the i-th cell is reused in each other cell or through several cells according to the schemes that are not necessarily identical for each j-th group, providing the required, i.e., ensuring the given communication quality, co-channel electromagnetic compatibility.

The next most important action, which ensures the achievement of the technical result together with the listed ones, is the action of making AT access to the radio channels. Namely, the AT access to the radio channels is carried out by a known means of allocating radio channels (for example, from the patent of the Russian Federation, N 04 B 7/26, 2154901) specified in the particular communication system, but with the following priority. Access AT is carried out primarily to the radio channels of the selected group of frequency bands with the largest number j (it is equal to Ki). In this case, the radio channels of a group of frequency bands with j = Ki may not be available in two cases: 1) AT is outside the radio coverage area of this group of frequency bands, and 2) AT is in the radio coverage area of this selected group of frequency bands, the largest number is fully occupied. In such a situation, access is made to the radio channels of the allocated frequency group with the group number reduced by one, i.e. for j = Ki-1. If radio channels are not available for this group, then access the radio channels of the next group with j = Ki-2. This process is sequentially repeated until access to the radio channels from the group of frequency bands allocated to provide in the aggregate radio coverage of the entire area of the i-th cell S _{0, i} .

 Control signals operate throughout the cell through specially selected channels.

 The implementation of the claimed method is schematically shown in the drawing. The radio communication system is presented in the form of a fragment of a set of cells covering the served territory.

 The implementation of the method is demonstrated by a simple example with a scheme of repeating frequency bands from a group of frequency bands allocated to provide in the aggregate radio coverage of the entire area of the cell, consisting of 7-cell clusters. These 7 groups of frequency bands are denoted by the letters A, B, C, D, E, F, G. Inside each cell, the contours of the radio coverage zones of each of the jth groups of PUFs of their BS conventionally located in the center of the cell are conventionally shown in circles. Each PPU group transmits and receives radio signals only from its j-th group of allocated frequency bands. In each cell, for example, two or three such zones are given, the internal of which form 3-element clusters, indicated by the numbers I, II, III, and the outer zones surrounding them form, for example, 4-element clusters and are indicated by the numbers 1, 2, 3, 4.

 In each i-th cell, the number of PUFs and groups of frequency bands can be different and the radio coverage zones can have different areas. Radio coverage zones by jth groups of allocated frequency bands should not intersect with radio coverage zones of adjacent (neighboring) cells, which are shown in dotted form in the figure.

 Reuse of the required number of frequency bands from the same j-th group used in the i-th cell can also be performed in each cell, i.e., for example, in each inner area of the radio coverage with the highest number repeat the same frequency group, for example, I.

 The AT access to the radio channels will be shown using the example of the central cell A, the radio coverage area of which is indicated by a dotted circle. Let AT be in the radio coverage zone I bounded by the first (inner) circle. Then he is granted access primarily to the radio channels of the selected group of frequency bands with the highest number, i.e. in this example, to I. If the radio channels of this group are busy, then AT provides access to the second stage - to the radio channels of the selected group of frequency bands with number 4, the radio coverage area of which is limited by the second circle covering the first. If again there are no free radio channels, then he is given access to the radio channels of the selected group of frequency bands with number A, the radio coverage of which extends to the entire cell.

 Now let AT be in the zone between the first and second circles. Then the radio channels of the group of frequency bands I are inaccessible to him and access is granted to the group of frequency bands 4, and in the absence of free channels, this group is also given access to the radio channels of the group of frequency bands A. frequency bands I and 4 and access is only possible to the radio channels of frequency band group A.

The AT density (the number of AT per unit area) can be considered with sufficient accuracy to be the same throughout the territory served by its BS. Then the number of radio channels M _{j, i} from the j-th group of frequency bands corresponding to the j-th radio coverage zone, on which the j-th radio control group transmit and receive radio signals of their BS is determined from the condition that the number of ATs per radio channel is constant, and for given areas S _{j, i of the} j-th radio coverage areas close to the integer part Mi • (S _{j, i} -S _{j + 1, j} ) / S _{0, i} , where j varies from 0 to Ki, and S _{Ki + 1 , i} ≡ 0 and the condition М _{0, i} + M _{1, i} + ... + M _{j, i} + ... + М _{Кi, i} = Mi is _fulfilled , here Mi is the number of radio channels from the frequency bands allocated for operation of the communication system .

Of practical importance is the option in which the number of radio channels M _{j, i of} each j-th group of frequency bands corresponding to the j-th radio coverage zone is set, on which the radio signals of the j-th group of the control panel transmit and receive their BS. The area S _{j, i of the} jth radio coverage zone in this embodiment, under the same assumption and condition, is equal to (S _{j-1, i} -S _{0, i} • М _{j-1, i} / Mi), where j varies from 1 to Ki , a M _{j, i} , as was indicated, are given for all j from 0 to Ki, and M _{0, i} + M _{1, i} + ... + M _{j, i} + ... + M _{Ki, i} = Mi .

 In the vicinity of the cell, there may be electronic means of other communication systems operating in a certain frequency band. In this case, on the same frequency bands, the jth PPU groups of their BS can transmit and receive radio signals on radio channels from the jth group of frequency bands with possibly large numbers j, i.e., corresponding to the internal jth radio coverage zones in the cell.

Using the claimed method (AP) of radio communications allows you to increase the capacity of the communication system or the number of radio channels per one frequency band. We show this with a few simple examples:
1) There is a communication system containing three BSs with a 3-element frequency band repetition scheme, and 10 frequencies are allocated to each BS. According to the traditional method of radio communication, we have 30 channels at 30 frequencies or 1 channel at 1 frequency. According to the ES in each BS, let us distinguish 2 groups of frequencies of 5 frequencies in each (5 in the “internal” radio coverage zone and 5 in the “external” one), with the “external” groups having a 3-element frequency repetition scheme, and the “internal” ones - the same for all BSs. Then the communication system will have the same 30 channels, but already at 5 • 3 + 5 = 20 frequencies, or 1.5 channels per 1 frequency.

 2) The communication system according to 1 example, but the "internal" group contains 7 frequencies, and the "external" group contains 3 frequencies. Then the communication system will have the same 30 channels, but already at 3 • 3 + 7 = 16 frequencies, or 1.875 channels at 1 frequency.

 3) An increase in the number of BS under the same conditions preserves the same number of channels at 1 frequency.

 4) The radio communication system is built in the form of 7-element clusters of 3 frequencies in each element, a total of 21 channels at 21 frequencies, or 1 channel per frequency. According to ES, let the “internal” group have 1 frequency and a 3-element frequency repetition scheme, and the “external” group have 2 frequencies and a 7-element frequency repetition pattern. Then the communication system will have the same 21 channels, non 2 • 7 + 1 • 3 = 17 frequencies, or 1.235 channels per frequency.

 The freed up frequency groups from the assigned communication systems can be added to the most stressful sections of the territory with heavy traffic. Accordingly, the cost and operating costs of the communication system will be reduced.

 The claimed radio communication method is universal and can be used in combination with other methods when using on the BS as antennas with a circular radiation pattern, and sector antennas, as well as in multi-level repetition schemes of a cellular communication network. We also note the following rather important circumstance. When creating a cellular network due to high capital investments, operators at the initial stages of the construction of their systems seek to provide the maximum radio coverage area with even a small amount of AT. A further increase in the subscriber capacity by increasing the number of BS, their sectorization and multiplication of the number of channels occurs after the system is put into operation. This approach requires a simple increase in the number of PSU BS, but it may entail a complete change in the structure of their antenna-feeder equipment (AFO). In order to minimize the cost of upgrading the AFO, which includes not only the cost of the equipment itself, but also quite laborious installation work, it is necessary at the initial stage of network design to provide ways for further development of the system as a whole and the possibility of changing the structure of individual BSs. The application of the claimed method of radio communication can significantly reduce these difficulties, and in some cases eliminate them.

 Thus, the distinguishing features of the proposed method of radio communication provide the emergence of new properties not achieved in the prototype and analogues. The analysis made it possible to establish: analogues with a set of features that are identical to all the features of the claimed technical solution are absent, which indicates the conformity of the claimed communication method to the “novelty” condition.

 The results of the search for known solutions in the field of communication in order to identify features that match the distinctive features of the prototype of the claimed method of radio communication, showed that they do not follow explicitly from the prior art. Also, the popularity of the influence of the actions provided for by the essential features of the claimed invention on the achievement of the specified result was not revealed. Therefore, the claimed invention meets the condition of patentability "inventive step".

Claims (4)

1. A radio communication method in a communication system based on the principle of frequency reuse, constructed in the form of N cells with a base station in each and cell areas S _{0, i} , where i varies from 1 to N, covering the entire served territory, providing radio communication of subscriber terminals located within the cell of their base station, and with the functional connection of all base stations with a common switching center and handover by the switching center from one base station to another when moving subscriber x terminals from one cell to another, in which the transceiver devices of the i-th base station and, accordingly, subscriber terminals located within the i-th cell, transmit and receive radio signals on M _i radio channels from the frequency bands allocated for the communication system they cover the entire area S _{0, i of the} i-th cell, repeating the required number of frequency bands used in the i-th cell, through several cells according to the scheme providing the required co-channel electromagnetic compatibility, by by means of radio channel isolation, access of subscriber terminals to radio channels in a predetermined order, characterized in that in each i-th cell of the base station transceiver devices, divided into j-th groups, where j varies from 0 to K _i , and K _i may be different for different cells, transmit and receive radio signals via radio channels of the j-x groups of frequency bands that do not contain the same frequency bands allocated from designated for communication M _i bandwidths system collectively radiopokryvaya area i-th cell and j-x zones embedded each other with contours that are quasi-similar to the radio coverage of the i-th cell, without intersecting with each other and with the radio-coverage contours of other cells adjacent to the i-th cell, and the radio communication signals over the radio channels on the j-th frequency band groups in the aggregate only jth zones of the i-th cell with areas S _{j, i} satisfying the condition S _{ki, i} <... <S _{j, i} <... <S _{2, i} <S _{1, i} <S _{0, i} , and the access user terminals to the radio channel allocation is performed means a group of frequency bands with the greatest number j, equal to K _i, and in case of unavailability of finding subscriber terminals in the i-th cell outside the radio coverage zone with the highest number, or if located in this zone, but when the radio channels are fully occupied, the groups of transceiver devices with the highest number j are sequentially to provide priority access to the radio channels of the groups of transceiver devices with decreasing by one j numbers up to radio transceivers group allocated for a plurality of radio coverage throughout the area S _{0, i i-th} cell, the reuse necessary number of frequency bands of the j-th group used in the i-th cell, produce in each different cell or a few cells of optionally the same for each j-th group of patterns providing the desired cochannel electromagnetic compatibility. 2. The method according to claim 1, characterized in that the number of communication frequency bands M _{j, i} allocated for the jth group is selected close to the integer part of the ratio M _i (S _{j, i} -S _{j + 1, i} ) / S _{0 , i} for j from 0 to K _i -1 and М _i S _{j, i} / S _{0, i} for j = К _i , provided that M _{0, i} + M _{1, i} + ... M _{j, i} + ... M _{Ki, i} = M _i . 3. The method according to claim 1, characterized in that in each i-th cell, the j-th group of transceivers of their base station transmit and receive radio signals over radio channels from the j-th group of frequency bands corresponding to the j-th radio coverage area S _{j, i} equal to (S _{j-1, i} -S _{0, i} · M _j- 1 _{, i} / M _i ), where j from 1 to К _i , and М _{j, i are} given for j from 0 to К _i , provided that M _{0, i} + M _{1, I} + ... M _{j, i} + ... M _{Ki, i} = M _i . 4. The method according to claim 1, or 2, or 3, characterized in that in each i-th cell, the j-th group of transceiver devices of their base station with possibly large numbers j transmit and receive radio signals over radio channels from the j-th group frequency bands corresponding to the jth radio coverage zone most adjacent to the frequency bands occupied by electronic means of other communication systems located in the vicinity of the i-th cell.