CN1205813A - Frequency assignment in cellular telecommunications network - Google Patents
Frequency assignment in cellular telecommunications network Download PDFInfo
- Publication number
- CN1205813A CN1205813A CN 96199294 CN96199294A CN1205813A CN 1205813 A CN1205813 A CN 1205813A CN 96199294 CN96199294 CN 96199294 CN 96199294 A CN96199294 A CN 96199294A CN 1205813 A CN1205813 A CN 1205813A
- Authority
- CN
- China
- Prior art keywords
- sub
- district
- frequency
- districts
- telecommunication network
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Mobile Radio Communication Systems (AREA)
Abstract
In a cellular telecommunications network consisting of cells around a reference cell, two or more cells are assigned for use the same group of RF carrier frequency pairs. One of the two or more cells has a different predetermined order of preference of the RF carrier frequency pairs than the other so as to minimise interference.
Description
The present invention relates to a kind of in cellular radio telecommunications network the method to the base station assigns carrier frequency, and relate to a kind of radio telecommunication network that comprises this Frequency Distribution.
In cellular wireless system of knowing such as mobile phone, provide the network of a plurality of base stations that have antenna respectively.Moving user unit has antenna, and this antenna must be a non-directional, and this is because the user moves in the sub-district of being everlasting or moves to another sub-district from a sub-district.Therefore, generally adopt 7 cell frequency re-use pattern therefors (seven-cell frequency reuse pattern), it for example is described in " Cellular RadioSystem (cellular wireless system) ", Balston D M Macario RCV Editors, Artech HouseInc, 1993, p9-13.
The invention provides a kind of cellular telecommunication network, it comprises and is distributed in a plurality of sub-districts on every side, benchmark sub-district (reference cell), can distribute two sub-districts the same cluster (group) of (pairs) to be carried out frequency shift (FS) (frequency-offset) duplex communication at least with the RF carrier frequency, thereby make the different districts in the described sub-district around the benchmark sub-district have the right different predetermined priority of the described RF carrier frequency of use to greatest extent, thereby make minimum interference basically.
Best, each described sub-district has different predetermined priority each other with other sub-district of described sub-district.Perhaps, around the right number of frequency is less than in the benchmark sub-district, during with the number sum of the sub-district of annular spread and this benchmark sub-district, has the right liftoff farthest distribution in these sub-districts of RF carrier frequency of identical predetermined priority, thereby make minimum interference basically.
The present invention has obvious advantage when bandwidth is subjected to strict restriction.Disturb, especially cochannel disturbs minimizing of (co-channel interference) to allow to carry out frequency reuse, and has therefore improved call capacity.
The invention still further relates to a kind of right method of RF carrier radio frequency of in cellular telecommunication network, selecting to use, this cellular telecommunication network comprises and is distributed in around the benchmark sub-district and is assigned with a plurality of sub-districts of carrying out the frequency shift (FS) duplex communication with the right same cluster of RF carrier frequency, wherein makes the different sub-district around this benchmark sub-district have the right different predetermined priority of the described RF carrier frequency of use to greatest extent.
The RF carrier frequency is to being used in each base station of sub-district and the duplex communication between each subscriber unit.Subscriber unit preferably is positioned at the place, fixed position.The most handy radio transmits.
The preferred embodiments of the present invention are described below with reference to accompanying drawings by way of example, in the accompanying drawing:
Fig. 1 is the schematic diagram that expression comprises the system of base station (BTE-Base Terminating Equipment:BTE-base station terminal equipment) and subscriber unit (NTE-Network Terminating Equipment:NTE-network-termination device);
Fig. 2 is the frame structure of expression duplex link and the schematic diagram of sequential;
Fig. 3 be expression each all have the topological diagram of a part of preferred network of 4 sub-districts of base station and subscriber unit; With
Fig. 4 is the topological diagram of the major part of this preferred network.
Fundamental system
As shown in Figure 1, this optimum decision system is the part of telephone system, and wherein the part from the switch to user has line loop to be substituted by the full duplex radio link between fixed base stations and the fixed subscriber unit.This optimum decision system comprises the duplex wireless link and is used to implement the transmitter and receiver of necessary agreement.This optimum decision system with in the art known digital cellular mobile telephone system such as GSM similarity is arranged.This system adopts the agreement based on hierarchical mode, specifically adopts a kind of hierarchical mode that has as lower floor: PHY (physical layer), MAC (media access control layer), DLC (data link control layer), NWK (network layer).
Compare with GSM, a difference is: in this optimum decision system, subscriber unit is positioned at the place, fixed position, does not need handover (hand-off arrangement) and the further feature relevant with mobility.This means, for example, in this optimum decision system, can adopt directive antenna and civil power.
Each base station in this optimum decision system is equipped with 6 duplex wireless links with 12 frequency operations selecting from whole Frequency Distribution, thus the interference minimum between near the base station making.The frame structure and the sequential of this duplex link are shown among Fig. 2.Each duplex wireless link includes the up link from the subscriber unit to the base station, and the down link from the base station to the subscriber unit with fixed frequency skew.Down link is TDM, and up link is TDMA.PI/4-DQPSK is adopted in modulation to all links, and the basic frame structure of all links is that the frame of per 2560 bits is 10 time slots, i.e. 256 bits of each time slot.Bit rate is 512kbps.Down link is transmission continuously, and is provided with the broadcast channel that is used for fundamental system information.When not having user's message transmission, downlink transmission continues to adopt basic frame and structure of time slot, and comprises suitable filling model (fill pattern).
For up link and downlink transmission, have two kinds of time slots: common (normal) time slot, it uses after call setting; And pilot time slot, it uses during call setting.
The common time slot of each down link includes the synchronizing information of 24 bits, is thereafter the S field (it comprises 8 bit heads) of the appointment of 24 bits, is the D field of the appointment of 160 bits after again.After this is the forward error correction and the 8 bit fillers of 24 bits, is the broadcast channel of 12 bits afterwards.This broadcast channel is formed by a plurality of sections in each time slot of a frame, the common descending common signaling channel that forms by base station transmits of each section, this broadcast channel also comprises control messages, does not have necessary other information of operation that connect (connectionless) message and this system, and this control messages comprises time slot table link information, multiframe and superframe information such as (slot lists).
During call setting, each descending pilot frequency time slot include frequency correction data and only have short S field and do not have D field information be used for the initialized training sequence of receiver.
Uplink time slot consists essentially of two kinds of data of different types groupings (data packet).First kind of grouping is called pilot packet, for example is used for the ALOHA call request before connection is set, and carries out the auto-adaptive time calibration.The another kind of type of packet is known as common (normal) grouping, and it is used for when setting up calling, and owing to use the auto-adaptive time calibration, is bigger packet therefore.
The packet of 244 bits on 4 bit duration slopes (ramp) before and after comprising, each up link ordinary groups is respectively arranged.All the other bits of this slope and 256 bit time slots provide guard interval (guardgap), are used to prevent the interference from contiguous time slot (neighbouring slots) that causes owing to the sequential mistake.Each subscriber unit is adjusted the sequential of its slot transmission, arrives the required time of base station with compensating signal.Each up link general data packets comprises the synchrodata of 24 bits, is the S field and the D field of similar number bit afterwards, and this is as the situation of the common time slot of each down link.
Each uplink pilot time slot includes the pilot data grouping, and this pilot data is grouped into 192 bit long, and respectively there are 4 bit slopes front and back, and this slope has defined the guard interval of the expansion of 60 bits.Owing to there is not an available time sequence information, and if do not have it, then propagation delay causes that contiguous time slot produces and disturbs, therefore this bigger guard interval is necessary.This pilot packet comprise 64 bits synchronously, be the S field of 104 bits afterwards, this S field is with 8 bit starts of header (SOH), and finishes with 16 bit cyclic redundancy, 2 reservation bits, 14 FEC bits and 8 tail bits.Here there is not D field.
S field in the above-mentioned packet can be used for two types signaling.First type is MAC signaling (MS), and is used to the signaling between the MAC layer of the MAC layer of base station and subscriber unit, and this moment, sequential was important.Second type is called auxiliary (associated) signaling, and it can slowly can be fast, and is used to the base station in DLC or the NWK layer and the signaling of subscriber unit.
D field is the maximum data field, comprises digitize voice under the situation of common (normal) phone, but also can comprise the non-speech data sample.
In this optimum decision system, stipulate, subscriber unit differentiates that (authentication) adopts query-response agreement (challenge response protocol) to carry out general encryption by voice or data and unpredictable sequence by the password bit of key stream generator generation are made up, and this key generator is synchronized to the Hyper Frame Number (super-frame number) of transmission.
In addition, the signal of transmission by scrambling to remove the dc component.
Disturb
Two kinds of interference are arranged: cochannel disturbs and adjacent-channel interference (adjacent channel interference), as described later.Typical cellular topology figure shown in Fig. 3.The benchmark sub-district is the sub-district that comprises base station BTE 1.Usable frequency is divided into several subclass, and label is fs1, fs2, fs3.
Cochannel disturbs
Operate with identical frequency set the sub-district that comprises base station BTE 1 and base station BTE 4.Transmission from subscriber unit NTE 1 to base station BTE 1 causes that the cochannel to base station BTE 4 disturbs.The accurate level that disturbs depends on two path losses between the sub-district.But, make through-put power minimize the level minimum that can make the uplink channel interference that appears on the base station BTE 4 from subscriber unit NTE 1.
Adjacent-channel interference
The sub-district that comprises base station BTE 1, BTE 2 and BTE 3 has frequency set independent of each other, its respectively label be fs1, fs2 and fs3.Each frequency set includes several selected frequencies, and label is fn, and wherein n increases with the increase of frequency.Yet, the best of usable frequency collection is used and is related to base station BTE 1, BTE 2 with the side frequency (adjacent frequencies) that appears in this frequency set and BTE3 (promptly, be used on the base station BTE 1 if label is the selected rf frequency of n, then label is that the selected rf frequency of n ± 1 will be used by base station BTE 2 or BTE 3).If the power by subscriber unit NTE 1 transmission in adjacent channel (adopting above-mentioned labelling method is n ± 1) does not have the path loss between enough decay and subscriber unit NTE 1 and base station BTE 2 or the base station BTE 3 lower, then may occur disturbing.By guaranteeing that subscriber unit NTE 1 to be no more than transmitting near minimum power of successfully receiving, can further alleviate this effect.
Reducing cochannel disturbs
Fig. 4 is illustrated in the RF carrier frequency group who is distributed in this preferred network in each sub-district.Frequency pool is meant frequency range or frequency selection, or in other embodiments, can be single frequency.In Fig. 4, benchmark sub-district label is C0, and the frequency pool of its distribution is C by label.Each sub-district (cells immediately adiacent to cell C0) of tight neighbor cell C0 has the frequency pool distribution that label is A, B, D, E, F, G, and all these frequency pools are different with the frequency pool C0 of benchmark sub-district.Yet each all has the frequency pool distribution C identical with sub-district C0 sub-district C1 to C6, therefore, if arrive sub-district C0 from any one signal in these sub-districts, causes interference.Each sub-district includes base station and a plurality of subscriber unit, and (promptly on down link) transmitted continuously with the frequency of all distribution in this base station.Suitable Frequency Distribution can reduce interference level, especially on up link, i.e. and the interference level of the signal that receives by the base station.
For the interference level minimum that causes on the C0 of sub-district by using identical frequency pool to make, the RF channel is assigned in the calling in these sub-districts with the predetermined priority of RF frequency mode (RF frequency patterns) (pairs).
As shown in the table, according to the descending of priority, 6 preferential frequency modes are arranged:
Table
| The sub-district | ?C0 | ?C1 | ?C2 | ?C3 | ?C4 | ?C5 | ?C6 |
| The RF carrier frequency is to (label is 1 to 6) | ??1 ??2 ??3 ??4 ??5 ??6 | ??6 ??1 ??2 ??3 ??4 ??5 | ????5 ????6 ????1 ????2 ????3 ????4 | ????4 ????5 ????6 ????1 ????2 ????3 | ????3 ????4 ????5 ????6 ????1 ????2 | ????2 ????3 ????4 ????5 ????6 ????1 | ????4 ????5 ????6 ????1 ????2 ????3 |
Each all has 6 can be right by the RF carrier frequency that its base station and subscriber unit communicate.Each is shown in the above table the priority that is assigned with, and wherein C1 to C6 has identical frequency pool.For example, carrier frequency 1 is the first-selection of sub-district C0, but is not the first-selection with any other sub-district C1 to C6 of same frequency group.Equally, each sub-district (C1 to C6, but except the C6) has different priority.
If the number that the RF carrier frequency is right is less than the number of the sub-district with identical dividing frequency group, the unique priority of RF carrier frequency to distributing is derived in each sub-district when then impossible in these sub-districts.Therefore, must consider the location of the sub-district of shared RF frequency pool, and select to reduce to greatest extent the right distribution of RF carrier frequency of interference.Example in the above table can be by relatively sub-district C6 and C3 find out.These two sub-districts all have the identical right priority of RF carrier frequency.As shown in Figure 3, sub-district C6 separates preferably with C3, and it has maximum distance in area group C0 to C6.
Below example of the present invention has been described with reference to sub-district with omnidirectional antenna.The present invention also can be applicable to have the sub-district of the directive antenna of one or more outside sensings, and as all having a plurality of sub-districts of 3 antennas, the orientation of these antenna is separated by 120 °.
Claims (14)
1. cellular telecommunication network, comprise and be distributed in a plurality of sub-districts on every side, benchmark sub-district, at least two sub-district right same cluster of designated RF carrier frequency are carried out the frequency shift (FS) duplex communication, one in wherein said at least two sub-districts has the use described RF carrier frequency right predetermined priority different with another or other each sub-district of described at least two sub-districts, disturbs thereby eliminate.
2. cellular telecommunication network as claimed in claim 1, nearest sub-district has the right different predetermined priority of the described RF carrier frequency of use in wherein said at least two sub-districts.
3. cellular telecommunication network as claimed in claim 1 or 2, each of wherein said at least two sub-districts all have with described at least two sub-districts in the different predetermined level in other sub-district.
4. cellular telecommunication network as claimed in claim 1 or 2, wherein when the right number of frequency is less than the number sum of the sub-district (cells next to the reference cell) of contiguous benchmark sub-district and described benchmark sub-district, have the sub-district of using the right identical predetermined priority of RF carrier frequency at least in described two sub-districts and separately distributed, disturb to eliminate by liftoff farthest.
5. the described cellular telecommunication network of arbitrary as described above claim, the right distinct group of the designated RF carrier frequency in wherein adjacent sub-district (neighbouring cells) carries out the frequency shift (FS) duplex communication.
6. the described cellular telecommunication network of arbitrary as described above claim, wherein said RF carrier frequency is carried out duplex communication to the sub-district that is used between base station and subscriber unit.
7. cellular telecommunication network as claimed in claim 6, wherein subscriber unit is positioned at the fixed position.
8. the described cellular telecommunication network of arbitrary as described above claim wherein communicates with radio.
9. the described cellular telecommunication network of arbitrary as described above claim wherein sends message in the predetermined time slot in the regular length time frame.
10. one kind is used for selecting to use the right method of RF carrier wave wireless frequency at cellular telecommunication network, described cellular telecommunication network comprises and is distributed in around the benchmark sub-district and a plurality of sub-districts that the right same cluster of designated RF carrier frequency is carried out the frequency shift (FS) duplex communication that wherein each in described at least two sub-districts around the benchmark sub-district all has the different predetermined priority of using described RF carrier frequency in the group.
11. the right method of RF carrier wave wireless frequency is used in selection as claimed in claim 10, nearest sub-district has the right different predetermined priority of the described RF carrier frequency of use in wherein said at least two sub-districts.
12. use the right method of RF carrier wave wireless frequencies as claim 10 or 11 described selections, each of wherein said at least two sub-districts all have with described at least two sub-districts in other the different predetermined priority in sub-district.
13. use the right method of RF carrier wave wireless frequency as claim 11 or 12 described selections, wherein when the right number of frequency is less than the number sum of the sub-district of contiguous benchmark sub-district and described benchmark sub-district, have the sub-district of using the right identical predetermined priority of RF carrier frequency at least in described two sub-districts and separately distributed, disturb to eliminate by liftoff farthest.
14. use the right method of RF carrier wave wireless frequency as any one the described selection in the claim 10 to 13, the wherein adjacent sub-district right distinct group of designated RF carrier frequency carries out the frequency shift (FS) duplex communication.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96199294 CN1205813A (en) | 1995-11-10 | 1996-11-07 | Frequency assignment in cellular telecommunications network |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9523078.5 | 1995-11-10 | ||
| GB9524592.4 | 1995-12-01 | ||
| GB9620532.3 | 1996-10-02 | ||
| CN 96199294 CN1205813A (en) | 1995-11-10 | 1996-11-07 | Frequency assignment in cellular telecommunications network |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1205813A true CN1205813A (en) | 1999-01-20 |
Family
ID=5129411
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 96199294 Pending CN1205813A (en) | 1995-11-10 | 1996-11-07 | Frequency assignment in cellular telecommunications network |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1205813A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1943141B (en) * | 2004-03-16 | 2015-07-08 | 诺基亚公司 | Method, device and system for duplex communications |
| CN107395313A (en) * | 2017-07-24 | 2017-11-24 | 中国联合网络通信集团有限公司 | A kind of method and device for reducing inter-cell interference |
-
1996
- 1996-11-07 CN CN 96199294 patent/CN1205813A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1943141B (en) * | 2004-03-16 | 2015-07-08 | 诺基亚公司 | Method, device and system for duplex communications |
| CN107395313A (en) * | 2017-07-24 | 2017-11-24 | 中国联合网络通信集团有限公司 | A kind of method and device for reducing inter-cell interference |
| CN107395313B (en) * | 2017-07-24 | 2019-04-30 | 中国联合网络通信集团有限公司 | A kind of method and device reducing inter-cell interference |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6584084B1 (en) | Expanded carrier capacity in a mobile communications system | |
| US6061340A (en) | Transmission of digital data messages in digital telephony | |
| US7251226B2 (en) | Communication system with fast control traffic | |
| US20120281598A1 (en) | Wireless access system using multiple modulation formats in TDD frames and method of operation | |
| US20050141452A1 (en) | Base station for facilitating handover in TDMA communications | |
| EP2053900B1 (en) | Radio communication devices and method for controlling frequency selection | |
| EP2290888B1 (en) | Wireless parallel communications system and method therefor | |
| US6044086A (en) | Control signal transmission in digital radio telephony | |
| CN1160473A (en) | Method for restricting channel access depending on subscriber classes and system loading | |
| EP0860057A1 (en) | Method and apparatus for power control in a telephone system | |
| WO1997017768A9 (en) | Method and apparatus for power control in a telephone system | |
| US6597681B1 (en) | Time-based mapping of control channel bursts in a wireless communication network | |
| CN1205813A (en) | Frequency assignment in cellular telecommunications network | |
| WO1996008940A2 (en) | Call handoff in digital radio telephony | |
| EP0867095B1 (en) | Enabling a subscriber unit in a radio network | |
| EP0860061B1 (en) | Digital telephony using control messages transmitted in time slots for rf frequency allocation | |
| WO1999011084A1 (en) | Apparatus and method for transmitting data | |
| EP0860060B1 (en) | Frequency assignment in a cellular telecommunications network | |
| CN1205814A (en) | Digital telephone using control messages transmitted in time slots for RF frequency allocation | |
| WO2001019103A1 (en) | Method for overlaying packet-switched data services on a wireless network | |
| CN1285664A (en) | Method and system for selecting channel in radio communication system | |
| MXPA98003688A (en) | Digital telephony using control messages transmitted in time slots for frequency allocation | |
| WO1996035277A1 (en) | A method and apparatus for transmitting a digital data message according to a second frame format | |
| CN1205811A (en) | Method and appts. for power control in a telephone system | |
| CN1161124A (en) | Method and apparatus for selection of a radio channel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |