Summary of the invention
The technical problem to be solved in the present invention is to propose a kind of cell user communication method and system thereof based on OFDM, makes to reduce when improving frequency efficiency that the user disturbs and the inter-cell user interference in the sub-district in the mobile communication system.
For addressing the above problem, the technical scheme that the present invention proposes is as follows:
A kind of cell user communication method based on OFDM comprises step:
User in each sub-district in the OFDM mobile communication system is carried out packet transaction; And
Make and take the transmission that different time domain symbol resources communicates data in the sub-district between the different grouping user respectively, wherein, the communication data that drops on the grouping user transmission in the cell edge region that marks off is carried out spread spectrum and/or error correction coding processing.
Preferably, the size order according to each user received signal intensity in the sub-district carries out packet transaction to user in the sub-district.
Preferably, the described process that user in the sub-district is carried out packet transaction specifically comprises:
Set in advance the signal intensity ratio threshold value that each is used to divide adjacent packets;
The user receives the measurement signal strength signal intensity that emission comes from the different base station transmitter in the sub-district; And
The strongest signal strength that receives is compared with time ratio of strong signal strength signal intensity and each signal intensity ratio threshold value that sets in advance;
Described user draws the grouping that self should be divided into according to comparative result; And
The object information of the grouping that self should be divided into is reported system side.
Preferably, the signal to noise ratio size order according to each user's received signal in the sub-district carries out packet transaction to user in the sub-district.
Preferably, the described process that user in the sub-district is carried out packet transaction specifically comprises:
Set in advance the signal to noise ratio ratio threshold value that each is used to divide adjacent packets;
At least two adjacent base station receivers receive the signal to noise ratio of measuring from same user's transmission signals;
System side compares the maximum signal to noise ratio that described two adjacent base station receivers measure at least with time ratio of big signal to noise ratio and each signal to noise ratio ratio threshold value that sets in advance; And
Draw the grouping that described user should be divided into according to comparative result.
Preferably, the described process that user in the sub-district is carried out packet transaction specifically comprises:
Set in advance the signal-noise ratio threshold value that each is used to divide adjacent packets;
System side compares the snr of received signal of the user feedback that base station receiver receives with each signal-noise ratio threshold value that sets in advance; And
Draw the grouping that described user should be divided into according to comparative result.
Preferably, apart from size order user in the sub-district is carried out packet transaction apart from the base station center position according to each user in the sub-district.
Preferably, take the transmission that different subframe time domain symbol resources communicate data in the sub-district between the different grouping user respectively.
Preferably, take the transmission that different time domain sign resources in the same subframe communicates data in the sub-district between the different grouping user respectively.
Preferably, the grouping user that snr of received signal is big in the sub-district preferentially takies the transmission that time domain symbol resources in the same subframe communicates data.
Preferably, user in each sub-district can be divided into two groups.
A kind of cell user communication system based on OFDM comprises:
Packet processing unit is used for user in each sub-district of OFDM mobile communication system is carried out packet transaction;
Data transmission unit is used to make in the sub-district after described packet processing unit is handled take the transmission that different time domain symbol resources communicates data respectively between the different grouping user;
The spread processing unit is used for the communication data that drops on the grouping user transmission in the cell edge region after the described packet processing unit processing is carried out spread processing;
The error correction coding processing unit is used for that the communication data that drops on the grouping user transmission in the cell edge region after the described packet processing unit processing is carried out error correction coding and handles.
Preferably, described packet processing unit carries out packet transaction according to the size order of each user received signal intensity in the sub-district to user in the sub-district.
Preferably, described packet processing unit carries out packet transaction according to the signal to noise ratio size order of each user's received signal in the sub-district to user in the sub-district.
Preferably, described packet processing unit carries out packet transaction apart from size order to user in the sub-district apart from the base station center position according to each user in the sub-district.
The beneficial effect that the present invention can reach is as follows:
Technical solution of the present invention is by being divided at least two groups with the user in each sub-district in the OFDM cell mobile communication systems, and make each grouping user take the transmission that different OFDM time domain symbol resources communicates data respectively, the different grouping user will be owing to using different subcarrier carrying communication datas to avoid user's interference in the sub-district in the sub-district like this, make inter-cell user disturb because user in the sub-district is divided into groups simultaneously, and make the different OFDM time domain symbol resources transport communication data of different grouping CU and reduced.Therefore technical solution of the present invention just can so that the inter-cell user in the OFDM cell mobile communication systems is disturbed and the sub-district in user's interference on the basis of saving frequency resource, all reduced greatly, thereby improved the user capacity of OFDM cell mobile communication systems.
Embodiment
Because the OFDM technology will be used widely in cell mobile communication systems, therefore in order to improve the user capacity of mobile communication system, how to reduce in the sub-district intrinsic in the OFDM cell mobile communication systems that the user disturbs and inter-cell user to disturb will be a very important problem, technical solution of the present invention is primarily aimed at this kind situation, the mobile subscriber that utilization is positioned at cell boarder is subjected to the comparatively serious characteristics of presence of intercell interference, a kind of OFDM scheme of carrying out user grouping based on disturbed condition has been proposed, thereby make inter-cell user disturb and the sub-district in user's interference all reduced greatly, fundamentally to improve the user capacity of mobile communication system.
In the OFDM mobile communication system, generally can adopt the mode of a plurality of subcarrier parallel transmission communication datas, be that several OFDM symbols (as 6 OFDM symbols) constitute a subframe, the subcarrier at each OFDM symbol place can be distributed to one or more user in different time sections and carry communication data, and the present invention program supposes that here the OFDM symbol that each cell base station uses keeps synchronous or synchronously accurate in time.
Be explained in detail to the present invention program's main realization principle, embodiment and to the beneficial effect that should be able to reach below in conjunction with each accompanying drawing.
Please refer to Fig. 1, this figure is the main realization principle flow chart that the present invention is based on the cell user communication method of OFDM, and its main implementation procedure is as follows:
Step S10 carries out packet transaction to user in each sub-district in the OFDM mobile communication system;
The present invention program will be disturbed different characteristics according to different user in the same sub-district here, the power that the user that gives chapter and verse the is disturbed signal to noise ratio size of user's received signal (or according to) is carried out packet transaction to the user in the same sub-district, that is to say, to be disturbed more weak user's (or the signal to noise ratio of received signal is higher) user to be divided into one group, and the user that will be disturbed stronger user (or the signal to noise ratio of received signal is lower) be divided into another the group, the group number of wherein cutting apart is more than two or two.
So as seen, the present invention program can come the user in the same sub-district is carried out packet transaction here based on one of following three kinds of modes, certainly in specific implementation process, other packet transaction mode can also be arranged:
First kind of mode: can carry out packet transaction to user in the sub-district according to the size order of each user received signal intensity in the sub-district, its specific implementation process is as follows:
Set in advance the signal intensity ratio threshold value that each is used to divide adjacent packets;
The user receives and measures the signal strength signal intensity that emission comes from the different base station transmitter in the sub-district; And
The strongest signal strength that receives is compared processing with time ratio and above-mentioned each signal intensity ratio threshold value that sets in advance of strong signal strength signal intensity;
This user just can draw the grouping that self should be divided into according to above-mentioned comparative result;
The object information of this user grouping that self should be divided into that will draw at last reports system side.
As: suppose that it is example that the user in the same sub-district is divided into two groups according to the signal to noise ratio size of its received signal, promptly shown in Figure 2, usually a little less than being subjected to inter-cell user to disturb according to center of housing estate zone user, the intensity of general received signal is higher, so center of housing estate zone user is divided into first group of user (Group1); And the user of cell edge region is subjected to the inter-cell user interference stronger usually, and the intensity of received signal is lower, so the user of cell edge region is divided into second group of user (Group2).Near the signal strength signal intensity that all different base station transmitters are launched at first measuring based on user in above-mentioned first kind of mode sub-district so also contrasts the signal strength signal intensity that these receive, if the ratio of the strongest signal strength that receives and inferior strong signal strength signal intensity is greater than certain fixed signal strength threshold (as 9dB), so this user it is the user who is positioned at the center of housing estate zone with the apprizing system side, promptly belong to first group of user; It is the user who is positioned at cell edge region otherwise it is with the apprizing system side, promptly belongs to second group of user.
The second way: can carry out packet transaction to user in the sub-district according to the signal to noise ratio size order of each user's received signal in the sub-district, this mode can have following two kinds of implementation procedures, and one is:
Set in advance the signal to noise ratio ratio threshold value that each is used to divide adjacent packets;
At least two adjacent base station receivers that system surveys receive and measure the signal to noise ratio from same user's transmission signals;
System side compares the maximum signal to noise ratio that above-mentioned two adjacent base station receivers measure at least with time ratio and above-mentioned each signal to noise ratio ratio threshold value that sets in advance of big signal to noise ratio; And
Draw the grouping that this user should be divided into according to above-mentioned comparative result.
As above-mentioned shown in Figure 2, be subjected to inter-cell user to disturb usually according to center of housing estate zone user a little less than, the signal to noise ratio of general received signal is higher, so center of housing estate zone user is divided into first group of user (Group1); And the user of cell edge region is subjected to the inter-cell user interference stronger usually, and the signal to noise ratio of received signal is lower, so the user of cell edge region is divided into second group of user (Group2).Like this based on the above-mentioned second way, at first several base station receivers of system side are measured the transmission signals signal to noise ratio from same tested mobile subscriber simultaneously, if the ratio of the peak signal signal to noise ratio through measure finding to measure and time large-signal signal to noise ratio is greater than certain fixing signal to noise ratio ratio thresholding (as 9dB), drawing this tested mobile subscriber so is the user who is positioned at the center of housing estate zone, belongs to first group of user; Otherwise drawing this tested mobile subscriber is the user who is positioned at cell edge region, belongs to second group of user.
It two is: set in advance the signal-noise ratio threshold value that each is used to divide adjacent packets;
System side compares snr of received signal and above-mentioned each signal-noise ratio threshold value that sets in advance of the user feedback that base station receiver receives; And
Draw the grouping that the user of this feedback snr of received signal should be divided into according to comparative result.
As above-mentioned shown in Figure 2, suppose that it is example that the user in the same sub-district is divided into two groups according to the signal to noise ratio size of its received signal, the grouping that this mobile subscriber should be divided into can recently be judged according to the noise of the received signal of mobile subscriber feedback in the base station, if the snr of received signal of this mobile subscriber feedback is greater than certain fixing signal-noise ratio threshold (as 9dB), can draw this mobile subscriber so is the user who is positioned at the center of housing estate zone, belongs to first group of user; Otherwise can draw this mobile subscriber is the user who is positioned at cell edge region, belongs to second group of user.
The third mode: can according to each user in the sub-district apart from the base station center position apart from size order user in the sub-district is carried out packet transaction, its concrete implementation procedure is similar with above-mentioned dual mode, repeats no more here.
Step S20 makes and takies the transmission that different time domain symbol resources communicates data in each sub-district between the different grouping user respectively;
Wherein can take the transmission that different subframe time domain symbol resources communicate data respectively between the different grouping user in the sub-district, be that each user in every component group takies the transmission that different frequency subcarrier in the same whole subframe communicates data, the subframe time domain symbol resources that the different grouping CU is different respectively.As shown in Figure 3, the different grouping user takies the OFDM running time-frequency resource distribution schematic diagram that different subframe time domain symbol resources communicate the transmission of data respectively in the sub-district in order to make based on the inventive method principle, wherein Fig. 3 is divided into center of housing estate zone user group and cell edge region user with the user with inside, sub-district and organizes two and be grouped into routine OFDM running time-frequency resource distribution schematic diagrames, suppose to have 6 OFDM symbols an OFDM subframe inside, here the user who all the OFDM symbols in first subframe is offered the center of housing estate zone uses, the user who simultaneously all the OFDM symbols in second subframe is offered cell edge region uses, wherein for this two components group user, the concrete number of subframes that adopts can be fixed, and also can carry out the dynamic change adjustment according to concrete needs.
In addition, can also be between the different grouping user in the sub-district by taking the transmission that different time domain sign resources in the same subframe communicates data respectively, be that the different grouping user can take the different time domain sign resources in the same OFDM subframe respectively, preferably, the grouping user that snr of received signal is bigger in the sub-district preferentially takies the transmission that time domain symbol resources in the same subframe communicates data.As shown in Figure 4, the different grouping user takies first kind of OFDM running time-frequency resource distribution schematic diagram that same subframe time domain symbol resources communicates the transmission of data respectively in the sub-district in order to make based on the inventive method principle, wherein Fig. 4 is divided into center of housing estate zone user group and cell edge region user with the user with inside, sub-district and organizes two and be grouped into routine OFDM running time-frequency resource distribution schematic diagrames, suppose to have 6 OFDM symbols an OFDM subframe inside, here the user who several (as preceding 3) symbols of the front in the same OFDM subframe is offered the center of housing estate zone uses, and the user that remaining (as back 3) symbol offers cell edge region in will this same subframe uses, wherein for this two components group user, symbolic number in the same OFDM subframe of concrete employing can be fixed, and also can carry out the dynamic change adjustment according to concrete needs.
And for example shown in Figure 5, the different grouping user takies second kind of OFDM running time-frequency resource distribution schematic diagram that same subframe time domain symbol resources communicates the transmission of data respectively in the sub-district in order to make based on the inventive method principle, wherein among Fig. 5 so that all users of inside, sub-district are divided into six OFDM running time-frequency resource distribution schematic diagrames that are grouped into example according to the signal to noise ratio size of its received signal, suppose to have 6 OFDM symbols an OFDM subframe inside, here sort apart from the far and near distance of center of housing estate position (the perhaps power disturbed of user or signal to noise ratio size of received signal etc.) all mobile subscribers according to the mobile subscriber to inside, sub-district, be distributed in first grouping with user with the most close center of housing estate position, allow this first the grouping in the same OFDM subframe of all CUs in first OFDM symbol, by that analogy ..., to be distributed in last group (promptly the 6th grouping) apart from center of housing estate position user farthest, allow last OFDM symbol (i.e. the 6th symbol) in this same OFDM subframe of all CUs in the 6th grouping.
In addition in order to obtain better communication efficiency, also need in the inventive method the above-mentioned communication data that drops on the grouping user transmission in the cell edge region that marks off is carried out spread spectrum and/or error correction coding processing, disturb further to reduce to drop on the inter-cell user that produces between the grouping user in the cell edge region.
To sum up as seen the inventive method principle and specific implementation process thereof the present invention proposes a kind of technical scheme that can improve the user capacity of OFDM cell mobile communication systems.In technical solution of the present invention, requiring all base stations in the ofdm system all is synchronous or quasi synchronous in time, identical OFDM frame structure is adopted in all base stations, every frame comprises a plurality of OFDM symbols, the user of cellular cell inside is divided into more than two groups or two groups, and requires the first group of user who divides out to send or receive data with second group of user in the different time periods.That is to say that the time that the different grouping user in the cellular cell transmits and receive data staggers.As above-mentioned grouping situation shown in Figure 2, first grouping user sends or receives data simultaneously, and second grouping user sends or receive data simultaneously, but two grouping user send or receive data in the different time periods.Wherein for the user in first grouping, because they are positioned at the central area of base station, user's interference is eliminated owing to different user uses different sub-carrier frequencies in its sub-district; And for the interference of inter-cell user, because first grouping user (Group1) of a certain base station center location is far away from first grouping user (Group1) of other base station center location, therefore the interference of inter-cell user will be very little for first grouping user.Wherein for the user (Group2) in second grouping; in like manner user's interference also can be eliminated owing to different user has used different sub-carrier frequencies in the sub-district; yet second grouping user (Group2) is owing to be positioned at cell edge region; therefore be subjected to the interference meeting of inter-cell user even more serious; promptly each user (Group2) in second grouping can bear the interference from second grouping user (Group2) of other neighbor cells; therefore for the user in second grouping; in order to make it obtain satisfied communication performance, the communication data that the user in this grouping is transmitted preferably adopts expansion technique or adopts the strong error correction coding of low code rate to protect processing.
Promptly; for first grouping user that is positioned at the center of housing estate zone; existing less inter-cell user disturbs; thereby has a higher communication signal to noise ratio; for these users thereby do not need to adopt the safeguard measure (as to the strong error correction coding of these user's communications The data spread spectrums and slow coding speed etc.) of height to avoid Communication Jamming, and can realize the data communication of two-forty.And for second grouping user of cell edge region; because they exist comparatively serious inter-cell user to disturb; lower communication signal to noise ratio is arranged; therefore need to adopt the strong error correction coding of spread spectrum or high protection degree to come the communication data of user's transmission in this group is handled, disturb to avoid inter-cell user.
According to above-mentioned analysis as seen, the inventive method can so that the inter-cell user in the OFDM cell mobile communication systems is disturbed and the sub-district in all reductions greatly of user's interference, thereby improved the user capacity of OFDM cell mobile communication systems.
Accordingly, the cell user communication method based on OFDM of above-mentioned proposition according to the present invention, the present invention goes back and then has proposed a kind of cell user communication system based on OFDM here.Please refer to Fig. 6, this figure is the main composition structured flowchart that the present invention is based on the cell user communication system of OFDM, wherein mainly comprises packet processing unit 10 and data transmission unit 20, and the main effect of these two component units is as follows:
Packet processing unit 10 is used for user in each sub-district of OFDM mobile communication system is carried out packet transaction; Wherein this packet processing unit 10 can carry out packet transaction to user in the sub-district according to the size order of each user received signal intensity in the sub-district; Can also carry out packet transaction to user in the sub-district according to the signal to noise ratio size order of each user's received signal in the sub-district; Can also carry out packet transaction apart from size order to user in the sub-district apart from the base station center position according to each user in the sub-district.
Data transmission unit 20 is used to make in the sub-district after above-mentioned packet processing unit 10 is handled take the transmission that different time domain symbol resources communicates data respectively between the different grouping user.
Please refer to Fig. 7, this figure is that embodiment behind the increase spread processing unit forms structured flowchart in the system of the present invention, wherein on the main composition architecture basics of above-mentioned Fig. 6, can also and then comprise spread processing unit 30, to be used for that the communication data that drops on the grouping user transmission in the cell edge region after above-mentioned packet processing unit 10 processing is carried out spread processing, disturb with the user who reduces the minizone.
Please refer to Fig. 8, this figure is that embodiment behind the increase error correction coding processing unit forms structured flowchart in the system of the present invention, wherein on the main composition architecture basics of above-mentioned Fig. 6, can also and then comprise error correction coding processing unit 40, handle to be used for that the communication data that drops on the grouping user transmission in the cell edge region after above-mentioned packet processing unit 10 processing is carried out error correction coding, disturb with the user who reduces the minizone.
The specific implementation details of other correlation techniques in the system wherein of the present invention please refer to the associated description of relevant art details in the invention described above method, no longer gives here too much to give unnecessary details.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.