Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/12—Wireless traffic scheduling
  • H04W72/1263—Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
  • H04W72/1273—Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows of downlink data flows
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/50—Allocation or scheduling criteria for wireless resources
  • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
  • H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B7/00—Radio transmission systems, i.e. using radiation field
  • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
  • H04B7/022—Site diversity; Macro-diversity
  • H04B7/024—Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems

Definitions

• the present invention relates to user scheduling techniques in a Long Term Evaluation-Advanced (LTE-A) system, and more particularly to a user scheduling method and a base station in cooperative scheduling.
• LTE-A Long Term Evaluation-Advanced
• Each node in the coordinated transmission set can obtain data information, and at the same time, the data is transmitted through a plurality of nodes or a node on a Physical Downlink Shared Channel (PDSCH).
• PDSCH Physical Downlink Shared Channel
• the coordinated cell scheduling for the user includes initial scheduling in the cell and iterative scheduling of one or more small intervals, and performs user scheduling after performing multi-user pairing search in each iterative scheduling. How to quickly and effectively select scheduling users in collaborative scheduling is a problem to be solved in the prior art.
• the technical problem to be solved by the present invention is to provide a user scheduling method and a base station in cooperative scheduling, which reduces the amount of calculation in the iterative process and improves system performance.
• the present invention provides a user scheduling method in cooperative scheduling, which is applied to an advanced long term evolution system, including: a coordinated cell determines user pairing information in an initial scheduling and saves, and the coordinated cell is in each subsequent When the iterative scheduling starts, the scheduling user information determined by the other coordinated cells other than the coordinated cell in the previous scheduling is obtained, according to the interference situation of the scheduling user determined by the coordinated cell user to the other coordinated cells, and combined with the initial scheduling. Saved The user pairing information of the coordinated cell determines a pre-scheduled user of the coordinated cell.
• the above method also has the following characteristics:
• the pre-scheduled user of the coordinated cell is one or more users of the coordinated cell user that do not interfere with the scheduling user determined by other coordinated cells other than the coordinated cell, or the user of the coordinated cell is determined according to other coordinated cells.
• the degree of interference of the scheduled users is from small to large before sorting
• M users the number of users in the coordinated cell is N, and M is an integer greater than or equal to 1 and less than or equal to N.
• the coordinated cell determines the pre-scheduled user, it is determined that one or more user pairs in the saved user pairing information are included in the pre-scheduled user, and the system performance of the user pair is calculated and calculated separately.
• the system performance corresponding to each user in the pre-scheduled user is scheduled, and the user or user pair with the best system performance is determined as the scheduled scheduling user.
• the coordinated cell When the coordinated cell user's interference degree to the scheduled user determined by the other coordinated cell users is greater than the system-set interference threshold, the coordinated cell does not set the pre-scheduled user in the iterative scheduling, and further in this iteration The scheduling user is not set in the scheduling.
• the coordinated cell performs multiple iteration scheduling, and the condition that the coordinated cell stops the iterative scheduling is: the number of times the iterative scheduling is performed reaches the system set number of times, or the scheduling users determined by the two consecutive iterations are the same.
• the present invention provides a base station in cooperative scheduling, which is applied to an advanced long term evolution system, including an initial scheduling processing module, and an iterative scheduling processing module.
• the initial scheduling processing module is configured to: The user pairing information is determined in the scheduling process, and the user pairing information is saved; the iterative scheduling processing module is configured to: determine the scheduling user by using the saved user pairing information in the iterative scheduling of the coordinated cell.
• the iterative scheduling processing module is further configured to: at each start of the iterative scheduling, learn the scheduling user information determined by the other coordinated cells other than the coordinated cell in the previous scheduling, according to the coordinated cell user determining the other coordinated cells. The interference situation of the user is scheduled, and the pre-scheduled user of the coordinated cell is determined.
• the above base station also has the following features:
• the pre-scheduled user of the coordinated cell is one or more users of the coordinated cell user that do not interfere with the scheduled users determined by other coordinated cells, or the degree of interference of the coordinated cell user according to the scheduled users determined by other coordinated cells.
• the first M users are sorted from small to large; the number of users in the coordinated cell is N, and M is an integer greater than or equal to 1 and less than or equal to N.
• the above base station also has the following features:
• the iterative scheduling processing module is further configured to: after determining the pre-scheduled user, determine that one or more user pairs in the saved user pairing information are included in the pre-scheduled user, and calculate a scheduling corresponding to the user pair
• the system performance is calculated separately, and the system performance corresponding to each user in the pre-scheduled user is calculated, and the user or user pair with the best system performance is determined as the scheduled scheduling user.
• the above base station also has the following features:
• the iterative scheduling processing module is further configured to: when the coordination degree of the coordinated user determined by the coordinated cell user to the scheduling user determined by the other coordinated cell users is greater than the interference threshold set by the system, the pre-scheduling is not set in the current iterative scheduling. The user, in turn, does not set the scheduling user in this iterative scheduling.
• the above base station also has the following features:
• the iterative scheduling processing module is further configured to: perform multiple iterative scheduling, and stop the iterative scheduling.
• the condition is that the number of executions of the iterative scheduling reaches the set number of times of the system, or the scheduling users determined by the two consecutive iterations are the same.
• the user pairing information is saved in the initial scheduling process and used in subsequent iterative scheduling.
• multi-user pairing search is not required, without degrading systemicity.
• the calculation amount in the iterative scheduling is reduced, the system resources occupied by the iterative scheduling are reduced, and the system processing time is accelerated, so that the performance in the entire region tends to be optimal.
• FIG. 1 is a flow chart of a user scheduling method in cooperative scheduling of an embodiment. Preferred embodiment of the invention
• the present invention is applied to an advanced long-term evolution system.
• the cooperative area to which the present invention is applicable generally includes a plurality of coordinated cells, and each coordinated cell can support Single-User Multi-Input Multi-Output (SU-MIMO).
• Multi-User Multi-Input Multi-Output (MU-MIMO) antenna mode the user in each coordinated cell independently measures the channel quality of the cell to the serving cell, and feeds back the measurement information to In the service area.
• SU-MIMO Single-User Multi-Input Multi-Output
• MU-MIMO Multi-User Multi-Input Multi-Output
• the base station in the cooperative scheduling includes an initial scheduling processing module and an iterative scheduling processing module.
• the initial scheduling processing module is configured to determine user matching information in an initial scheduling process of processing the coordinated cell, and save the user pairing information.
• An iterative scheduling processing module configured to determine a scheduled user using the saved user pairing information in an iterative scheduling of the coordinated cell.
• the iterative scheduling processing module learns the scheduling users determined by the other coordinated cells in the previous scheduling, and determines the pre-commissioning of the coordinated cells according to the interference situation of the coordinated users determined by the coordinated users to other coordinated cells.
• Schedule users The determined pre-scheduled user is one or more users of the coordinated cell users that do not interfere with the scheduling users determined by other coordinated cells, or the interference degree of the coordinated cell users according to the scheduled users determined for other coordinated cells is small.
• the first M users after the large sort; the number of users in the coordinated cell is N, and M is an integer greater than or equal to 1 and less than or equal to N.
• An iterative scheduling processing module after determining a pre-scheduled user, determining that one or more user pairs in the saved user pairing information are included in the pre-scheduled user, calculating and scheduling the corresponding system performance of the user, and respectively The system performance corresponding to each user in the pre-scheduled user is calculated, and the user or user pair with the best system performance is determined as the determined scheduling user.
• the iterative scheduling processing module may perform multiple iterative scheduling, and the conditions for stopping the iterative scheduling are as follows: the number of times of performing the iterative scheduling reaches the set number of times of the system, or the scheduling users determined by the two consecutive iterations are the same.
• the iterative scheduling processing module does not set the pre-scheduled user in the iterative scheduling, and further The scheduling user is not set in the iterative scheduling.
• the user scheduling method in cooperative scheduling includes:
• Step 101 The coordinated cell determines user pairing information in an initial scheduling and saves the information.
• the initial scheduling means that each coordinated cell performs the local scheduling for the first time without considering other cell information. Specifically, after receiving the channel measurement information of the user in the cell, the coordinated cell completes the initial scheduling of the cell without considering the scheduling situation of other cells, and may perform multi-user scheduling to save all possible users when the channel state permits. Pairing information. User pairing is based on the user's channel information. Two users (ie, user pairs) that are orthogonal or quasi-orthogonal or two users that meet certain performance requirements can be paired.
• the pairing information retained in the invention is pairing information that satisfies the performance requirements set by the system.
• the performance requirements set by the system can be the interference strength (or the degree of orthogonality) between the two users.
• Step 102 The coordinated cell determines the scheduled user in the subsequent iterative scheduling by using the saved user pairing information.
• the coordinated cell may perform multiple iterative scheduling, and each iteration scheduling includes the following steps:
• the coordinated cell learns the scheduled users determined by the other coordinated cells in the last scheduling. When the first iteration is scheduled, its last scheduling is the initial scheduling.
• the pre-scheduled user of the coordinated cell is one or more users of the coordinated cell user that do not interfere with the scheduled users determined by other coordinated cells, or the degree of interference of the coordinated cell user according to the scheduled users determined by other coordinated cells.
• the first M users are sorted from small to large; the number of users in the coordinated cell is N, and M is an integer greater than or equal to 1 and less than or equal to N.
• the system may also set a interference threshold for determining the degree of interference between the users of the coordinated cell and other users of the coordinated cell, and the interference degree of the coordinated user determined by the user of the coordinated cell to the scheduled user of the other coordinated cell is greater than the interference threshold set by the system. That means that any user who schedules this cell will be the other If the cell forms interference that exceeds the system acceptance capability, the pre-scheduled user is not set in the current iteration scheduling in the coordinated cell, and the scheduling user is not set in this iterative scheduling.
• the coordinated cell may perform multiple iteration scheduling, and the condition that the coordinated cell stops the iterative scheduling is: the number of times the iterative scheduling is performed reaches the system set number of times, or the scheduling users determined by the two consecutive iterations are the same.
• the user pairing information is saved in the initial scheduling process and used in subsequent iterative scheduling, and the multi-user pairing search is not required in the iterative scheduling, without reducing the systemicity.
• Reduce the amount of computation in iterative scheduling reduce the system resources occupied by iterative scheduling, and speed up the system processing time, so that the performance in the entire region tends to be optimal.
• the invention can be implemented in a centralized, distributed or a combination of the two.
• the centralized method refers to summarizing the information of the users to be scheduled of all the coordinated cells on a central control point, so that the central control point independently completes the iterative scheduling. Finally, the scheduling result is sent to the corresponding coordinated cell; the distributed means that each coordinated cell obtains the pre-scheduling information of other coordinated cells by itself, completes the pre-scheduling of the local cell by itself, and sends the pre-scheduling information of the current cell to other coordinated cells;
• the combination of the two and the distributed mode can be called a relay mode.
• Each coordinated cell supports MU-MIMO and SU-MIMO modes, and there are three users to be scheduled in the cooperative resource of each coordinated cell.
• the users to be scheduled of the coordinated cell A are respectively referred to as: user a1, user a2, and user a3.
• the users to be scheduled of the coordinated cell B are respectively referred to as: user bl, user b2, and user b3.
• the users to be scheduled of the coordinated cell C are respectively referred to as: user cl, user c2, and user c3. It is assumed that there is a strong interference between the user a2 and the user c2, the first stream of the user a2 and the user b3, and the second stream of the user c3 and the user b3. It is also assumed that the coordinated cell C with the smallest traffic is selected as the relay cell.
• the three coordinated cells independently perform local cell scheduling.
• the coordinated cell A completes the initial scheduling of the cell under the consideration of fairness and the current channel state of each user to be scheduled, and determines that the initial scheduled user is a2, and two users al and a3 can perform pairing.
• the coordinated cell B does not have user pairs that can be matched with each other in the completed channel state under the consideration of the fairness and the current channel state of each user to be scheduled; this scheduling is the SU-MIMO mode.
• the coordinated cell C completes the initial scheduling of the cell, and determines that the initial scheduling users are c2 and c3, and the scheduling is MU-MIMO mode.
• the scheduling result and the related information of the scheduling user are respectively sent to the relay cell;
• the relay cell aggregates the scheduling information of other cells, and then sends all the coordinated information to all the coordinated cells; After all the latest scheduling information sent by the cell, recalculate the scheduling plan of the cell;
• Cooperative cell A in addition to considering fairness and current channel state of each to-be-scheduled user, considers scheduling of coordinated cell B (scheduling user b3, and using two streams) and scheduling of coordinated cell C (simultaneous scheduling c2 and c3) User), that is, in the case of satisfying certain performance of the cell, the performance loss caused by other coordinated cells should also be considered, thereby completing the initial scheduling of the cell.
• the possibility of scheduling 3 users in the cell is recalculated.
• the first stream of user a2 and user b3 has strong interference and interferes with user c2, so the priority of a2 scheduling is the smallest.
• the scheduled users determined by other coordinated cells do not exist.
• the user of the disturbance is a3, al.
• the pre-scheduled user in the first iteration is a3, al.
• a 3 and a1 of the reserved pairing information in the initial scheduling can be paired, and the system performance corresponding to the simultaneous scheduling of a3 and a1 is calculated, and the system performance corresponding to the single scheduling a3 or a1 is calculated, and the performance of scheduling two users is better than that.
• scheduling the performance of a3 or al separately it is determined that the scheduling users are a3 and al.
• the former M users that are determined by the coordinated cell to other coordinated cells according to the degree of interference of the scheduled users determined by the other coordinated cells are used as pre-scheduled users, and the coordinated cell
• the number of users is N, and M is an integer greater than or equal to 1 and less than or equal to N.
• the order is a3, al, a2, and the first two users are used as pre-scheduled users.
• the scheduling order of the scheduling priorities may be determined according to the current channel state of each user.
• Cooperative cell B in addition to considering fairness and current channel state of each to-be-scheduled user, considers scheduling of coordinated cell A (user a2) and scheduling of coordinated cell C (simultaneous scheduling of c2 and c3 users), that is, satisfying the cell In the case of certain performance, the performance loss caused by other coordinated cells should also be considered, and the initial scheduling of the cell is completed.
• the scheduling process it is assumed that the users 3, c2, and c3 have been scheduled, and the possibility of scheduling 3 users in the cell is recalculated.
• the first stream of user a2 and user b3 has strong interference
• the second stream of user c3 and user b3 has strong interference
• b3 scheduling has the lowest priority.
• the users who do not interfere with the scheduled users determined by other collaborative cells are bl , b2
• the pre-scheduled users in the first iteration are bl and b2. Find the pairing information retained in the initial schedule. Except that b3 can use two streams, there is no other pairing information, and the scheduling user can be determined to be b2.
• Cooperative cell C in addition to considering fairness and current channel state of each to-be-scheduled user, considers scheduling of coordinated cell A (user a2) and scheduling of coordinated cell B (scheduling user b3, and using two streams) In the case that the certain performance of the cell is satisfied, the performance loss caused by other coordinated cells should also be considered, and the initial scheduling of the cell is completed.
• the scheduling result and the related information of the scheduling user are respectively sent to the relay cell.
• the relay cell aggregates the scheduling information of other cells, it is first determined whether the scheduling result is completely consistent with the previous scheduling result. The discovery is not completely consistent, that is, the convergence state is not reached, and then all the scheduling information is sent to all the coordinated cells; after receiving all the latest scheduling information sent by the relaying cell, each coordinated cell recalculates the scheduling scheme of the current cell;
• the B-cell pre-scheduled user b2 in addition to considering the fairness and the current channel state of each user to be scheduled, the B-cell pre-scheduled user b2; the C-cell pre-scheduled user cl, and then completes the initial scheduling of the cell.
• the scheduling process under the assumption that b2 and cl have been scheduled, recalculates the possibility of scheduling three users in the cell, and the probability of scheduling the single user is: a3, al, a2; finding the reserved in the initial scheduling
• the pairing information, a3 and al can be paired, and the performance of the paired user is scheduled to be scheduled at the same time. The performance is better than the single scheduling a3. Therefore, the pre-scheduled result is two users of a1 and a3, that is, consistent with the previous scheduling result.
• Cooperative cell B in addition to considering fairness and the current channel state of each user to be scheduled, considers both A-cell pre-scheduling al, a3 two-user and C-cell pre-scheduled user cl, and then completes the initial scheduling of the cell.
• the scheduling process in the case that the users a, a3, and cl have been scheduled, recalculate the possibility of scheduling three users in the cell, and the probability of scheduling the single user is: b2, b3, bl, initial search
• the pairing information retained in the scheduling, b3 can be used in two streams. By calculating the simultaneous b3 two stream performance is better than the separate scheduling b2, so the pre-scheduled result is user b2, that is, consistent with the last scheduling result.
• Cooperative cell C in addition to considering the fairness and the current channel state of each user to be scheduled, considers both the A cell pre-scheduling al and a3 two users and the B cell pre-scheduled user b2; and then completes the initial scheduling of the cell.
• Scheduling process Under the assumption that al, a3 and b2 have been scheduled, recalculate the possibility of scheduling 3 users in the cell, and the probability of single user being scheduled is: cl, c3, c2, in the initial scheduling
• the reserved pairing information, c3 and c2 can be paired, recalculating and scheduling the performance of two users at the same time. By calculation, the performance of scheduling is better than that of separately scheduling cl, so the pre-scheduled results c2 and c3.
• the scheduling result and the related information of the scheduling user are respectively sent to the relay cell; after the relay cell aggregates the scheduling information of other cells, the first judgment is made. Whether the secondary scheduling result is completely consistent with the previous scheduling result, and the discovery is not completely consistent, that is, the convergence state is not reached, and then all the scheduling information is sent to all the coordinated cells; each coordinated cell receives all the latest scheduling sent by the relay cell. After the information, recalculate the scheduling scheme of the cell;
• the B-cell pre-scheduled user b2 in addition to considering the fairness and the current channel state of each user to be scheduled, the B-cell pre-scheduled user b2; the C-cell pre-scheduled users c2 and c3, thereby completing the initial scheduling of the cell.
• the scheduling process under the assumption that b2, c2, and c3 have been scheduled, recalculates the probability that three users in the cell are scheduled, and the probability of scheduling the single user is: a3, al, a2, and then find the initial scheduling.
• the reserved pairing information, a3 and al can be paired, and the performance of the paired user is calculated at the same time, and the performance is better than the single scheduling a3. Therefore, the pre-scheduled result is two users of a1 and a3, that is, consistent with the previous scheduling result.
• Cooperative cell B in addition to considering the fairness and the current channel state of each user to be scheduled, considers the A cell pre-scheduling al, a3 two users and the C cell pre-scheduled users c2 and c3, and then completes the initial scheduling of the cell.
• the scheduling process after assuming that the users al, a3, c2, and c3 have been scheduled, recalculates the possibility of scheduling three users in the cell, and the probability of scheduling the single user is: b2, bl, b3, initial search
• the pairing information retained in the scheduling, b3 can be used in two streams. By calculating the simultaneous b3 two stream performance is better than the separate scheduling b2, so the pre-scheduled result is user b2, that is, consistent with the last scheduling result.
• Cooperative cell C in addition to considering the fairness and the current channel state of each user to be scheduled, considers both the A cell pre-scheduling al and a3 two users and the B cell pre-scheduled user b2; and then completes the initial scheduling of the cell. Scheduling process: Since the previous cell A and cell B pre-scheduling results have not changed, the pre-scheduled result is still the last pre-scheduled result, that is, the users c2 and c3 are scheduled.
• the scheduling result and the related information of the scheduling user are respectively sent to the relay cell; after the relay cell aggregates the scheduling information of other cells, the scheduling result and the last scheduling result are first determined. Whether it is completely consistent, and it is found to be completely consistent, that is, to the convergence state, to notify all coordinated cell scheduling to reach the optimal state, and the scheduling ends; after receiving the scheduling completion information sent by the relay cell, each coordinated cell performs corresponding scheduling according to the final iteration result. .
• the final convergence is the iterative end condition, which may require a large number of iterations or a final convergence state.
• the end condition may also be to limit the number of iterations of the pre-scheduled, or the entire area meets a certain performance threshold.
• the industrial applicability uses the scheduling scheme in the invention.
• the user pairing information is saved in the initial scheduling process and used in subsequent iterative scheduling, and the multi-user pairing search is not required in the iterative scheduling.
• the computational complexity in iterative scheduling is reduced, the system resources occupied by iterative scheduling are reduced, and the system processing time is accelerated, so that the performance in the entire region tends to be optimal.

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• 2009
  • 2009-12-11 CN CN200910254329.XA patent/CN102098736B/zh not_active Expired - Fee Related
• 2010
  • 2010-12-09 US US13/380,864 patent/US20140099984A2/en not_active Abandoned
  • 2010-12-09 EP EP10835496.0A patent/EP2434804B1/de not_active Not-in-force
  • 2010-12-09 WO PCT/CN2010/079624 patent/WO2011069461A1/zh not_active Ceased

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