JP2011239393A - Method of joint scheduling in carrier aggregation system and apparatus for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of joint scheduling in a carrier aggregation system and an apparatus for the same.SOLUTION: A joint scheduling apparatus in a carrier aggregation system and a method of joint scheduling related to the invention send scheduling results between schedulers. This makes it possible for one scheduler to comprehensively take scheduling results provided by another scheduler into consideration when it performs scheduling. It also allows for scheduling at a frequency bandwidth or frequency more appropriate to a user. This makes it possible to fully utilize user-specific performance at each frequency bandwidth or frequency and achieve higher throughput.

Description

  The present invention relates to a mobile communication system, and more particularly to a joint scheduling method and apparatus in a carrier aggregation system.

  The 3rd Generation Partnership Project (3GPP), as an important organization in the mobile communication field, greatly promotes the standardization of 3G (The Third Generation), WCDMA (Wide Code Division Multiple Access), HSDPA (High Speed Downlink Packet Access), HSUPA A series of communication system standards including (High Speed Uplink Packet Access) has been established. In response to the challenges of broadband access technology and satisfying the demand for new services that are growing day by day, 3GPP launched standardization of 3G LTE (Long Term Evolution) technology at the end of 2004, further improving frequency spectrum efficiency To improve the performance of cell boundary users, reduce system delay, and provide faster access services for high-speed mobile users. In June 2008, 3GPP completed the LTE-A technical requirement report, and the minimum requirements of LTE-A, namely, downlink peak speed: 1 Gbps, uplink peak speed: 500 Mbps, uplink peak frequency spectrum utilization: 15 Mbps / Hz, downstream peak frequency spectrum utilization ratio: 30 Mbps / Hz was proposed. These parameters are much higher than the ITU's minimum technical requirement index and are clearly dominant.

  LTE-A supports continuous carrier aggregation and non-continuous carrier aggregation within and between bands, and the maximum aggregateable bandwidth can reach 100 MHz. In order to effectively use carriers in the early commercial period of LTE-A, that is, to ensure that LTE terminals can access LTE-A, each carrier should be able to be placed on a carrier that is backward compatible with LTE. It cannot be excluded that the carrier is designed only for the LTE-A system. Currently, 3GPP has identified 12 types of carrier aggregation application scenes according to the demands of telecommunications carriers. Of these, 4 types are the most important, but the continuous and non-continuous carrier aggregation scenes of FDD and TDD respectively. Concerning. In the LTE-A research phase, carrier aggregation related research focuses on improving the frequency spectrum utilization rate of continuous carrier aggregation and designing control channels for carrier aggregation scenes that are asymmetric in the vertical direction.

  Considering the demands on the new frequency spectrum by LTE-A, carriers will consider backward compatibility as well as the introduction of new frequency ranges and radio frequency links. Since new and existing radio frequency links are independent of each other, carriers have greater flexibility when deploying networks. In FIG. 1, a white ellipse indicates an existing sector, the frequency range F1 is 2 GHz, and an ellipse with a hatched line indicates a newly introduced sector, and the frequency range F2 is 3.5 GHz. When introducing a new F2 = 3.5 GHz frequency, the carrier turns the corresponding antenna according to environmental requirements, compensates for the boundaries of the original 2 GHz network sector, and the base station By performing joint scheduling for multiple component carriers, better throughput and network coverage are obtained.

  Another typical application scene is a base station with a small coverage newly placed in a heterogeneous network environment, such as a pico cell and a radio access point (RRH). As shown in FIG. 2 and FIG. 3, using a different frequency or frequency range from the traditional macro base station (indicated by a slanted ellipse in FIG. 2 and FIG. 3) between the macro base stations Similarly, carrier aggregation can be realized through connection and information exchange, and the system capacity can be improved. In the case of a pico cell, a newly introduced frequency or frequency range is used, and a user can simultaneously transmit data at two frequencies F1 and F2 within a coverable range.

  Each of the above-mentioned several types of application scenes has the following characteristics. Due to the difference in frequency, the path attenuation difference between a plurality of aggregated frequencies or frequency ranges is large, the information transmission delay is different, and the radio frequency link at each carrier frequency is relatively independent. Based on these features, so that it can be easily implemented, a relatively straightforward way of scheduling is to schedule each carrier using an independent scheduler.

  However, in addition to the above features, in the case of these several types of application scenes, the user set at each carrier frequency is different, and the performance difference between users at a different carrier frequency is relatively large. If only the independent scheduler is used, the scheduling result cannot sufficiently represent the system capacity and fairness because the user performance at other carrier frequencies is not considered.

上記式において、Ｎはユーザ総数を示し、R_n(t,r)は、ｎ個目ユーザのｔ個目スケジューリング時刻にｒ個目サブキャリアでの瞬時レートを示し、T_n(t,r)は、ｎ個目ユーザのｔ個目スケジューリング時刻（ｔ個目スケジューリング時刻を含む）までｒ個目サブキャリアでの平均レートを示し、

は、ｎ個目ユーザのｔ個目スケジューリング時刻にｒ個目サブキャリアでのＰＦスケジューリング因子関数を示し、ｊは、ｔ個目スケジューリング時刻にｒ個目サブキャリアでのＰＦスケジューリング最大のユーザであり、即ち、ｔ個目スケジューリング時刻にｒ個目サブキャリアでスケジューリングされるべきユーザであり、

は、スケジューリング履歴情報を更新する履歴情報更新関数を示し、ここで、スケジューリング履歴情報とはユーザの平均レートを示す。 Considering system capacity and fairness, conventional multicarrier systems often perform scheduling using a proportional fairness (PF) scheduling algorithm. The PF scheduling algorithm is represented by the following formulas (1) and (2) as one form.

In the above equation, N represents the total number of users, R _n (t, r) represents the instantaneous rate at the r _th subcarrier at the t th scheduling time of the n th user, and T _n (t, r) Is the average rate on the r th subcarrier up to the t th scheduling time (including the t th scheduling time) for the n th user,

Represents the PF scheduling factor function for the r-th subcarrier at the t-th scheduling time of the n-th user, and j is the user with the largest PF scheduling for the r-th subcarrier at the t-th scheduling time. That is, a user to be scheduled on the r th subcarrier at the t th scheduling time,

Indicates a history information update function for updating scheduling history information, where scheduling history information indicates an average rate of users.

  Equation (2) above shows one update method of the average rate. There are other update methods for the average rate. Different update schemes determine the performance of PF scheduling.

  A technical problem to be solved by an embodiment of the present invention is to provide a joint scheduling method and apparatus in a carrier aggregation system, and by passing user scheduling history information between schedulers, each frequency band / frequency during scheduling is provided. Therefore, it is to obtain a higher system throughput by comprehensively considering different performances of users.

  In order to solve the above technical problem, an embodiment of the present invention provides the following technical solution.

  A joint scheduling method applied to a unique scheduling improvement of a base station side scheduler in a carrier aggregation system, wherein the base station includes at least two schedulers, and the scheduler includes a scheduling factor including a first parameter at the time of independent scheduling. User scheduling is performed based on a scheduling factor calculated from the function, and after completion of scheduling, the first parameter is updated based on a history information update function including the second parameter and the first parameter before update. However, the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, and the second parameter is a scheduling result of the scheduler. In the joint scheduling method, all schedulers perform user scheduling in accordance with a predetermined scheduling history information delivery order until scheduling of all schedulers is completed within one scheduling time, and the delivery order is the first scheduler → The second scheduler → the third scheduler →... → the Lth scheduler → the first scheduler, where L is the total number of schedulers included in the base station, where user scheduling by each scheduler is The first parameter was changed using the scheduling history information received from the previous scheduler in the delivery order in the latest round, and then the scheduling factor function was used to calculate the scheduling factor function. Then, after completion of scheduling in each frequency band / frequency, each scheduler changes the first parameter using the scheduling history information received from the previous scheduler in the delivery order in the latest round, and then The scheduling history information is acquired by updating the history information update function, and the updated scheduling history information is delivered to the next scheduler in the delivery order.

  Preferably, in the method, the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler.

  Preferably, in the above method, the base station includes two schedulers, the first scheduler performs user scheduling in the first frequency band / frequency, the second scheduler performs user scheduling in the second frequency band / frequency, and When the scheduling time comes, first, the first scheduler calculates the PF scheduling factor of each user in the first frequency band / frequency based on the proportional fair PF algorithm and determines the users to be scheduled in the first frequency band / frequency. However, when calculating the PF scheduling factor from the PF scheduling factor function, the first frequency band / frequency is used up to the scheduling time immediately before the user using the scheduling history information of the user in the second frequency band / frequency. Flat in In the calculation to update the user scheduling history information with the history information update function in the first frequency band / frequency after completion of the scheduling of the first scheduler, the second frequency is calculated. Using the scheduling history information of the user in the band / frequency, the calculation is performed by changing the average rate in the first frequency band / frequency until the scheduling time immediately before the user, and then the updated first frequency band / Passing user scheduling history information in frequency to the second scheduler, which then calculates the PF scheduling factor for each user in the second frequency band / frequency based on the proportional fair PF algorithm to calculate the second frequency band / Identify users to be scheduled by frequency, but When the PF scheduling factor is calculated from the PF scheduling factor function, the average rate in the second frequency band / frequency until the scheduling time immediately before the user is obtained using the scheduling history information of the user in the first frequency band / frequency. In the calculation for updating the scheduling history information of the user with the history information update function in the second frequency band / frequency after the scheduling of the second scheduler is completed, the first frequency band is calculated. Using the scheduling history information of the user at the frequency / frequency, the calculation is performed by changing the average rate in the second frequency band / frequency until the scheduling time immediately before the user, and then the updated second frequency band / frequency. The user's scheduling history information is transferred to the first scheduler Hand over.

上記式において、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t-1,2)は、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までのスケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻に第１周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示し、上記した、第２周波数帯域／周波数でユーザのスケジューリング履歴情報を更新することは、下記式に従い、第２周波数帯域／周波数で各ユーザのスケジューリング履歴情報を更新することであり、

上記式において、Tr_n(t,2)は、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、ｍは現在スケジューリング時刻に第２周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。 Preferably, in the above method, updating the user scheduling history information in the first frequency band / frequency described above is updating the scheduling history information of each user in the first frequency band / frequency according to the following equation. ,

In the above equation, Tr _n (t, 1) represents scheduling history information up to the current scheduling time t of the nth user in the first frequency band / frequency, and Tr _n (t−1,2) is the second The scheduling history information of the nth user up to the (t-1) th scheduling time in the frequency band / frequency is shown, and R _n (t, 1) is the first frequency band / frequency of the nth user at the current scheduling time t. Where T _c is the size of the average rate statistics sliding window, j is the user scheduled in the first frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, N is the user The update of the user scheduling history information in the second frequency band / frequency described above indicates the total number, and the scheduling performance of each user in the second frequency band / frequency is determined according to the following formula. It is to update the information,

In the above equation, Tr _n (t, 2) represents scheduling history information up to the current scheduling time t of the nth user in the second frequency band / frequency, and Tr _n (t, 1) represents the first frequency band. / N indicates the scheduling history information of the nth user up to the current scheduling time t, and R _n (t, 2) indicates the instantaneous rate in the second frequency band / frequency of the nth user at the current scheduling time t. M represents a user scheduled in the second frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, and N represents the total number of users.

  The embodiment of the present invention further provides a joint scheduling apparatus applied to the original scheduling improvement of the base station side scheduler in the carrier aggregation system.

  The apparatus includes at least two schedulers and scheduling control means, and the scheduler of at least two schedulers is based on a scheduling factor calculated from a scheduling factor function including a first parameter at the time of independent scheduling. And after the completion of scheduling, the first parameter is updated based on a history information update function including the second parameter and the first parameter before update, where the first parameter is the scheduler And the second parameter is a scheduling result of the scheduler, and the scheduling control means can execute all scheduling within one scheduling time. Until scheduler scheduling is completed, all schedulers are controlled to perform user scheduling step by step in accordance with a predetermined scheduling history information delivery order, and the delivery order is the first scheduler → second scheduler → third scheduler → ... → L-th scheduler → first-scheduler, where L is the total number of schedulers included in the base station, where user scheduling by each scheduler is in the above delivery order in the latest round The first parameter is changed using the scheduling history information received from the immediately preceding scheduler, and the scheduling factor calculated from the scheduling factor function is used. However, each scheduler completes scheduling in each frequency band / frequency. The scheduling history information is obtained by updating the history information update function after updating the first parameter using the scheduling history information received from the previous scheduler in the delivery order in the latest round. The acquired scheduling history information is delivered to the next scheduler in the delivery order.

  Preferably, in the apparatus, the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler.

  Preferably, in the above apparatus, the at least two schedulers are two, the first scheduler performs user scheduling in the first frequency band / frequency, the second scheduler performs user scheduling in the second frequency band / frequency, The scheduling control means further controls user scheduling of the first scheduler when each scheduling time arrives, controls user scheduling of the second scheduler after scheduling of the first scheduler is completed, and controls the first scheduler According to the control of the scheduling control means, the PF scheduling factor of each user is calculated at the first frequency band / frequency based on the proportional fair PF algorithm, and the scheduling should be performed at the first frequency band / frequency. The user is specified, however, when calculating the PF scheduling factor from the PF scheduling factor function, the first frequency band is used until the scheduling time immediately before the user by using the scheduling history information of the user in the second frequency band / frequency. The calculation is performed by changing the average rate at the frequency / frequency, and after the scheduling of the first scheduler is completed, the user's scheduling history information is updated with the history information update function at the first frequency band / frequency. In the second frequency band / frequency, using the scheduling history information of the user, the calculation is performed by changing the average rate in the first frequency band / frequency until the scheduling time immediately before the user, and then the updated User scheduling history in the first frequency band / frequency The second scheduler calculates the PF scheduling factor of each user at the second frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and passes the second frequency band to the second scheduler. Identify the user to be scheduled at the frequency, but when calculating the PF scheduling factor from the PF scheduling factor function, the user's scheduling history information at the first frequency band / frequency is used to The calculation is performed by changing the average rate in the second frequency band / frequency until the scheduling time, and after the scheduling of the second scheduler is completed, the user's scheduling history information is updated with the history information update function in the second frequency band / frequency. And to update In calculation, using the scheduling history information of the user in the first frequency band / frequency, the calculation is performed by changing the average rate in the second frequency band / frequency until the scheduling time immediately before the user, and then the updated The user's scheduling history information is delivered to the first scheduler in the second frequency band / frequency.

上記式において、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t-1,2)は、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までのスケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻に第１周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示し、上記第２スケジューラは、更に下記式に従い、第２周波数帯域／周波数で各ユーザのスケジューリング履歴情報を更新し、

上記式において、Tr_n(t,2)は、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、ｍは現在スケジューリング時刻に第２周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。 Preferably, in the apparatus, the first scheduler further updates the scheduling history information of each user in the first frequency band / frequency according to the following formula:

In the above equation, Tr _n (t, 1) represents scheduling history information up to the current scheduling time t of the nth user in the first frequency band / frequency, and Tr _n (t−1,2) is the second The scheduling history information of the nth user up to the (t-1) th scheduling time in the frequency band / frequency is shown, and R _n (t, 1) is the first frequency band / frequency of the nth user at the current scheduling time t. Where T _c is the size of the average rate statistics sliding window, j is the user scheduled in the first frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, N is the user The second scheduler further updates the scheduling history information of each user in the second frequency band / frequency according to the following formula,

In the above equation, Tr _n (t, 2) represents scheduling history information up to the current scheduling time t of the nth user in the second frequency band / frequency, and Tr _n (t, 1) represents the first frequency band. / N indicates the scheduling history information of the nth user up to the current scheduling time t, and R _n (t, 2) indicates the instantaneous rate in the second frequency band / frequency of the nth user at the current scheduling time t. M represents a user scheduled in the second frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, and N represents the total number of users.

  The embodiment of the present invention further provides a joint scheduling method applied to the original scheduling improvement of the base station side scheduler in the carrier aggregation system. The base station includes at least two schedulers, and the scheduler performs scheduling of users based on a scheduling factor calculated from a scheduling factor function including a first parameter during its own scheduling, and after scheduling is completed, The first parameter is updated based on a history information update function including two parameters and the first parameter before update, where the first parameter is a user scheduling history in a frequency band / frequency corresponding to the scheduler. Information, and the second parameter is a scheduling result of the scheduler. In the joint scheduling method, user scheduling by each scheduler is received in the most recent time within one scheduling time. The first parameter is changed using the user's total scheduling history information, and then the scheduling factor calculated from the scheduling factor function is used. However, the user obtained by the latest update after the scheduling of all schedulers is completed. The first parameter is replaced using the total scheduling history information of the first and the second parameter is replaced using the scheduling result of all schedulers, and then the user's total scheduling history information is acquired by updating the history information update function. Then, the updated overall scheduling history information of the user is delivered to each scheduler.

  Preferably, in the method, the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler.

  Preferably, in the above method, the base station includes two schedulers, the first scheduler performs user scheduling in the first frequency band / frequency, the second scheduler performs user scheduling in the second frequency band / frequency, and When the scheduling time comes, the first and second schedulers calculate the PF scheduling factor of each user in the first and second frequency bands / frequency based on the proportional fair PF algorithm, respectively, and first and second frequency bands / frequency , But when calculating the PF scheduling factor from the PF scheduling factor function, the first and second schedulers are all in the first and second frequency bands / frequency and the user's total scheduling history Using information, just before the user The calculation is performed by changing the average rate in each frequency band / frequency until the scheduling time, and after the scheduling of the first and second schedulers is completed, the user's total scheduling history information in the first and second frequency bands / frequency In the history information update function, and in the calculation for updating, using the user's pre-update gross scheduling history information in the first and second frequency bands / frequency, The average rate in the first frequency band / frequency is changed until the scheduling time, and the second parameter in the history information update function is changed using the scheduling results of the first scheduler and the second scheduler, and then the history information is updated. By updating the function, the user's overall schedule in the first and second frequency bands / frequency To obtain a-ring history information, deliver the whole scheduling history information obtained by updating to each scheduler.

上記式において、Ts_n(t-1)は、第１、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までのスケジューリング履歴情報を示し、Ts_n(t)は、第１、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻ｔに第１周波数帯域／周波数でスケジューリングされるユーザを示し、ｍは現在スケジューリング時刻ｔに第２周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。 Preferably, in the method described above, updating the overall scheduling history information of the user in the first and second frequency bands / frequency described above is based on the following formula, and the scheduling history of each user in the first and second frequency bands / frequency is: Update information.

In the above equation, Ts _n (t−1) indicates scheduling history information up to the t−1th scheduling time of the nth user in the first and second frequency bands / frequency, and Ts _n (t) is The scheduling history information up to the current scheduling time t of the n-th user in the first and second frequency bands / frequency is shown, and R _n (t, 1) is the first frequency band of the n-th user at the current scheduling time t. / indicates the instantaneous rate of the frequency, R _n (t, 2) is the currently scheduled time t indicates the instantaneous rate in the second frequency band / frequency of the n th user, T _c is the average rate statistic for sliding window J represents a user scheduled in the first frequency band / frequency at the current scheduling time t, and m is scheduled in the second frequency band / frequency at the current scheduling time t. 1 ≦ n ≦ N, where N represents the total number of users.

  The embodiment of the present invention further provides a joint scheduling apparatus applied to the original scheduling improvement of the base station side scheduler in the carrier aggregation system. The apparatus includes at least two schedulers and parameter updating means, and the scheduler of at least two schedulers is based on a scheduling factor calculated from a scheduling factor function including the first parameter at the time of independent scheduling. Scheduling is performed, and after the scheduling is completed, the first parameter is updated based on a history information update function including the second parameter and the first parameter before the update. However, the first parameter is transmitted to the scheduler. User scheduling history information in a corresponding frequency band / frequency, wherein the second parameter is a scheduling result of the scheduler, provided that each scheduler performs user scheduling within one scheduling time. This is performed by using the scheduling factor calculated from the scheduling factor function after replacing the first parameter using the user's total scheduling history information received in the latest round, and the parameter updating means has one scheduling time. After the scheduling of all schedulers is completed, the first parameter is changed using the user's total scheduling history information obtained in the latest update, and the second parameter is changed using the scheduling result of all schedulers. The user's overall scheduling history information is acquired by updating the history information update function, and the updated user's overall scheduling history information is delivered to each scheduler.

  Preferably, in the apparatus, the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler.

  Preferably, in the above apparatus, the at least two base stations are two, the first scheduler performs user scheduling in the first frequency band / frequency, and the second scheduler performs user scheduling in the second frequency band / frequency. The apparatus further includes scheduling control means for controlling the first and second schedulers to perform user scheduling in their own frequency band / frequency when each scheduling time arrives, wherein the first scheduler includes: According to the control of the scheduling control means, the PF scheduling factor of each user is calculated in the first frequency band / frequency based on the proportional fair PF algorithm, and the user to be scheduled in the first frequency band / frequency is specified. However, PF schedule When calculating the PF scheduling factor from the switching factor function, the average rate in the first frequency band / frequency is calculated using the scheduling history information of the user in the first and second frequency bands / frequency until the scheduling time immediately before the user. Instead, calculation is performed, and the second scheduler calculates a PF scheduling factor of each user at the second frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control unit, and calculates the second frequency band / The user to be scheduled by frequency is specified, but when calculating the PF scheduling factor from the PF scheduling factor function, the user scheduling history information is used in the first and second frequency bands / frequency, and the user immediately before the user is scheduled. 2nd frequency until scheduling time The calculation is performed by changing the average rate in the band / frequency, and the parameter updating means further performs the scheduling in the first and second frequency bands / frequency after completion of scheduling at the current scheduling time of the first and second schedulers. In the calculation for updating and updating the total scheduling history information in the history information update function, using the user's pre-update total scheduling history information in the first and second frequency bands / frequency, The average rate in the first frequency band / frequency is changed until the scheduling time immediately before the user, and the second parameter in the history information update function is changed using the scheduling results of the first scheduler and the second scheduler. By updating the history information update function, users in the first and second frequency bands / frequency The overall scheduling history information of the user is obtained, and the updated overall scheduling history information is delivered to each scheduler.

上記式において、Ts_n(t-1)は、第１、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までのスケジューリング履歴情報を示し、Ts_n(t)は、第１、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻ｔに第１周波数帯域／周波数でスケジューリングされるユーザを示し、ｍは現在スケジューリング時刻ｔに第２周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。 Preferably, in the above apparatus, the parameter updating means further updates the scheduling history information of each user in the first and second frequency bands / frequency according to the following formula.

In the above equation, Ts _n (t−1) indicates scheduling history information up to the t−1th scheduling time of the nth user in the first and second frequency bands / frequency, and Ts _n (t) is The scheduling history information up to the current scheduling time t of the n-th user in the first and second frequency bands / frequency is shown, and R _n (t, 1) is the first frequency band of the n-th user at the current scheduling time t. / indicates the instantaneous rate of the frequency, R _n (t, 2) is the currently scheduled time t indicates the instantaneous rate in the second frequency band / frequency of the n th user, T _c is the average rate statistic for sliding window J represents a user scheduled in the first frequency band / frequency at the current scheduling time t, and m is scheduled in the second frequency band / frequency at the current scheduling time t. 1 ≦ n ≦ N, where N represents the total number of users.

  As can be seen from the above description, the joint scheduling method and apparatus in the carrier aggregation system according to the present invention has improved the scheduling method for determining the scheduling result based on its own scheduling history information. When one scheduler performs scheduling, the scheduling result of the other scheduler is considered comprehensively, and the user can be scheduled in a frequency band / frequency more suitable for itself. Higher system throughput can be obtained by fully utilizing the different performance of the users in the band / frequency.

One carrier aggregation application scene in the prior art is shown. Fig. 3 shows another carrier aggregation application scene in the prior art. Fig. 3 shows another carrier aggregation application scene in the prior art. 3 shows a flow of a joint scheduling method according to the first embodiment of the present invention. 1 shows a structure of a joint scheduling apparatus according to a first embodiment of the present invention. 7 shows a flow of a joint scheduling method according to a second embodiment of the present invention. 3 shows a structure of a joint scheduling apparatus according to a second embodiment of the present invention. The CDF curve figure of the throughput of the user in the Example of this invention obtained by simulation is shown. The serial delivery relationship of the scheduling history information in the Example of this invention is shown. 10 shows another serial delivery relationship of scheduling history information in the embodiment of the present invention. FIG. 6 shows delivery of scheduling history information between two schedulers in an embodiment of the present invention. FIG. 6 shows a parallel delivery relationship of scheduling history information in an embodiment of the present invention. In the embodiment of the present invention, when two schedulers are included, the delivery relationship of scheduling history information is shown.

  The present invention proposes a joint scheduling method between frequencies (frequency bands) in a carrier aggregation system, which is applied to a base station of a carrier aggregation system and improves the unique scheduling of the scheduler of the base station. The present invention delivers scheduling history information of users between schedulers, and when each scheduler performs user scheduling, it considers scheduling history information delivered from other schedulers and identifies users to be scheduled. Perform scheduling. Here, the scheduling history information is information specifically indicating the average rate of the user.

上記式（ａ）、（ｂ）において、ｊは、スケジューリングされるべきユーザを示し、ｆ（ｘ,ｙ）は、スケジューリング因子関数を示し、R_n(t)は、ユーザｎのｔ個目スケジューリング時刻ｔでの瞬時レート情報を示し、T_n(t-1)は、ユーザｎの（ｔ−１）個目スケジューリング時刻までのスケジューリング履歴情報を示し、Ｎは、ユーザ総数を示し、g(c,d)は、スケジューリング履歴情報を更新するスケジューリング履歴情報更新関数を示す。スケジューリング完成後に、スケジューラは、上記式（ｂ）に従い該スケジューラに対応する周波数帯域／周波数でのスケジューリング履歴情報を更新する。上記スケジューリングアルゴリズムは、伝統的なＰＦアルゴリズム、ＰＦアルゴリズムの各種の変形及びスケジューリング履歴情報に基づいて現在時刻のスケジューリング結果を特定する他のアルゴリズムを含む。上記式（ａ）、（ｂ）を満足する典型的なスケジューリングアルゴリズムは、ＰＦアルゴリズム、ＰＦアルゴリズムの各種の変形である。 When the base station has two or more schedulers, and the unique scheduling algorithm employed in each scheduler specifies the current scheduling result based on the scheduling history information, the scheduler is provided through the joint scheduling method according to the present invention. Higher system throughput can be obtained by improving the original scheduling and converting it to joint scheduling between schedulers. A scheduling algorithm that satisfies the following formulas (a) and (b) can be applied to the joint scheduling method according to the present invention, that is, improved through the joint scheduling method according to the present invention to obtain better system performance.

In the above equations (a) and (b), j represents a user to be scheduled, f (x, y) represents a scheduling factor function, and R _n (t) represents the t-th scheduling for user n. The instantaneous rate information at time t is shown, T _n (t-1) is scheduling history information up to the (t-1) -th scheduling time of user n, N is the total number of users, and g (c , d) represents a scheduling history information update function for updating scheduling history information. After the completion of scheduling, the scheduler updates scheduling history information in the frequency band / frequency corresponding to the scheduler according to the above equation (b). The scheduling algorithm includes a traditional PF algorithm, various modifications of the PF algorithm, and other algorithms that specify a scheduling result at the current time based on scheduling history information. Typical scheduling algorithms that satisfy the above equations (a) and (b) are PF algorithms and various modifications of the PF algorithms.

  Hereinafter, the present invention will be further described through specific embodiments with reference to the drawings.

<First embodiment>
The joint scheduling method according to this embodiment is applied to a base station of a carrier aggregation system, and the base station includes N (N ≧ 2) schedulers, and each scheduler performs user scheduling in its own frequency band / frequency. Do. The joint scheduling method according to the present embodiment improves the unique scheduling of the scheduler. The scheduler performs user scheduling based on a scheduling factor calculated from a scheduling factor function including the first parameter at the time of independent scheduling, and after the scheduling is completed, the second parameter and the first parameter before updating The first parameter is updated based on a history information update function including. However, the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, and the second parameter is a scheduling result of the scheduler.

  Specifically, in the joint scheduling method according to the present embodiment, all schedulers perform user scheduling step by step in accordance with the delivery order of predetermined scheduling history information until scheduling of all schedulers is completed within one scheduling time. Control. The delivery order is as follows: first scheduler → second scheduler → third scheduler →... → Lth scheduler → first scheduler, where L is the total number of schedulers included in the base station, However, the user scheduling by each scheduler is calculated from the scheduling factor function after changing the first parameter in the scheduling factor function using the scheduling history information received from the previous scheduler in the delivery order in the latest round. However, each scheduler uses the scheduling history information received from the immediately preceding scheduler in the delivery order after the completion of scheduling in the respective frequency band / frequency. Update function That the place of the first parameter, and obtains the scheduling history information by the updating of the history information update function, a scheduling history information acquired Update passes to the next scheduler in order the delivery.

As can be seen from the above description, in this embodiment, a serial scheduling scheme is used among the N schedulers of the base station. That is, when one scheduling time comes, each scheduler is scheduled one by one. After scheduling is completed, the scheduling history information is updated and delivered to the next scheduler, so that the user to be scheduled at the current scheduling time is determined based on the scheduling history information. Served in the scheduler. By analogy in this way, the above process is performed up to the last scheduler. After the scheduling is completed, the last scheduler similarly updates the scheduling history information of the user in the frequency band / frequency and delivers it to the first scheduler, and performs user scheduling based on the scheduling history information within the next scheduling time. Provide to the first scheduler to do. By passing the scheduling history information, a one-sided serial connection is formed between the schedulers. Therefore, the method according to the present embodiment can be referred to as serial scheduling from the image. FIG. 9 shows the delivery relationship of scheduling history information for N schedulers, where Tr _n (t, x) is the scheduling of user n in the xth scheduler (xth frequency band / frequency). The scheduling history information until time t is shown.

  If the transmission delay between the schedulers is larger than one transmission time interval (TTI), the scheduler uses the scheduling history information received from the previous scheduler in the delivery order in the latest round according to the above method during scheduling. In this case, the scheduling history information received in the latest round may be scheduling history information updated several times before the current scheduling time. In FIG. 10, when the inter-scheduler transmission delay is four TTIs, the scheduling history information delivery relationship between the three schedulers is shown. At this time, the scheduling history information of the four TTIs is not updated from the front.

  Hereinafter, the above method will be further described by taking as an example a carrier aggregation system in which a base station has two schedulers, and the scheduler adopts a PF scheduling algorithm at the time of independent scheduling. The carrier aggregation system includes a first scheduler that performs user scheduling in a first frequency band / frequency and a second scheduler that performs user scheduling in a second frequency band / frequency. In the case of the scheduler employing the PF scheduling algorithm, the scheduling factor function is a PF scheduling factor function of the PF algorithm, and the first parameter is an average rate of users in a frequency band / frequency corresponding to the scheduler. Please refer to FIG. When applied to two schedulers, the joint scheduling method according to the present embodiment specifically includes the following steps 11 to 14 when each scheduling time comes.

  In step 11, first, the first scheduler calculates a PF scheduling factor of each user in the first frequency band / frequency based on a proportional fair PF algorithm, and identifies users to be scheduled in the first frequency band / frequency. Perform scheduling. However, when calculating the PF scheduling factor from the PF scheduling factor function, the average rate in the first frequency band / frequency until the scheduling time immediately before the user using the scheduling history information of the user in the second frequency band / frequency. The calculation is performed instead of.

  In step 12, after the scheduling of the first scheduler is completed, the user's scheduling history information is updated with the history information update function in the first frequency band / frequency. In the calculation for updating, calculation is performed using the scheduling history information of the user in the second frequency band / frequency and changing the average rate in the first frequency band / frequency until the scheduling time immediately before the user. Then, the updated scheduling history information of the user is delivered to the second scheduler in the first frequency band / frequency after the update.

  In step 13, the second scheduler calculates a PF scheduling factor of each user in the second frequency band / frequency based on the proportional fair PF algorithm, and identifies and schedules users to be scheduled in the second frequency band / frequency. I do. However, when calculating the PF scheduling factor from the PF scheduling factor function, the average rate in the second frequency band / frequency until the scheduling time immediately before the user using the scheduling history information of the user in the first frequency band / frequency. The calculation is performed instead of.

  In step 14, after the scheduling of the second scheduler is completed, the user's scheduling history information is updated with the history information update function in the second frequency band / frequency. In the calculation for updating, calculation is performed using the scheduling history information of the user in the first frequency band / frequency and changing the average rate in the second frequency band / frequency until the scheduling time immediately before the user. Then, the updated scheduling history information of the user is delivered to the first scheduler in the second frequency band / frequency after the update.

  Hereinafter, the above steps will be described in more detail.

上記式において、第１スケジューラに対して、ｋの値は、１であり、第２スケジューラに対して、ｋの値は、２である。R_n(t,k)は、ｔ個目スケジューリング時刻にｋ個目周波数帯域／周波数でｎ個目ユーザの瞬時レートである。T_n(t,k)は、ｔ個目スケジューリング時刻までｋ目個周波数帯域／周波数でｎ個目ユーザの平均レートである。

は、ｔ個目スケジューリング時刻にｋ個目サブキャリアでｎ個目ユーザのＰＦスケジューリング因子関数である。ｊは、ｔ個目スケジューリング時刻にｋ個目周波数帯域／周波数でＰＦスケジューリング因子最大のユーザであり、即ち、ｔ個目スケジューリング時刻にｋ目個周波数帯域／周波数でスケジューリングされるべきユーザである。 In the prior art, the PF algorithm for unique scheduling is expressed as the following expression (3) as one expression format.

In the above equation, the value of k is 1 for the first scheduler and the value of k is 2 for the second scheduler. R _n (t, k) is the instantaneous rate of the nth user in the kth frequency band / frequency at the tth scheduling time. T _n (t, k) is an average rate of the nth user in the kth frequency band / frequency until the tth scheduling time.

Is the PF scheduling factor function of the nth user on the kth subcarrier at the tth scheduling time. j is a user having the largest PF scheduling factor in the k th frequency band / frequency at the t th scheduling time, that is, a user to be scheduled in the k th frequency band / frequency at the t th scheduling time.

Assuming that the current scheduling time is t, it can be seen that, in the prior art PF scheduling factor calculation process, the average rate T _n (t− (t− 1, k) must be used for calculation.

This embodiment improves the PF algorithm, introduces the concept of scheduling history information, and calculates the PF scheduling factor in one frequency band / frequency until the scheduling time (t−1) immediately before the user. The average rate T _n (t-1, k) in the first frequency band / frequency is not used, and T _n (t-1, k) is calculated in place of the user's scheduling history information in another frequency band / frequency. To do.

上記式は、第１スケジューラが現在スケジューリング時刻において、第１周波数帯域／周波数でＰＦスケジューリング因子最大のユーザｊを選択してスケジューリングを行うことを示す。 Assuming that the current scheduling time is t, in step 11, the first scheduler calculates the PF scheduling factor of each user in the first frequency band / frequency according to the following equation (4), and identifies the user j to be scheduled. . However, using the scheduling history information Tr _n (t−1,2) of the user in the second frequency band / frequency, the average rate T _n (t− (t−) in the first frequency band / frequency until the scheduling time immediately before the user. 1,1) was replaced.

The above formula shows that the first scheduler performs scheduling by selecting the user j having the maximum PF scheduling factor in the first frequency band / frequency at the current scheduling time.

上記式において、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t-1,2)は、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までのスケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻に第１周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。上記式（５）において、同じく第２周波数帯域／周波数でユーザのスケジューリング履歴情報Tr_n(t-1,2)を用いて、該ユーザの直前のスケジューリング時刻まで第１周波数帯域／周波数での平均レートT_n(t-1,1)を代えた。 In step 12, after the scheduling of the first scheduler is completed, the scheduling history information of each user is updated in the first frequency band / frequency according to the following equation (5).

In the above equation, Tr _n (t, 1) represents scheduling history information up to the current scheduling time t of the nth user in the first frequency band / frequency, and Tr _n (t−1,2) is the second The scheduling history information of the nth user up to the (t-1) th scheduling time in the frequency band / frequency is shown, and R _n (t, 1) is the first frequency band / frequency of the nth user at the current scheduling time t. Where T _c is the size of the average rate statistics sliding window, j is the user scheduled in the first frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, N is the user Indicates the total number. In the above equation (5), using the user scheduling history information Tr _n (t−1,2) in the second frequency band / frequency, the average in the first frequency band / frequency until the scheduling time immediately before the user. The rate T _n (t-1,1) was changed.

上記式は、第２スケジューラが現在スケジューリング時刻において、第２周波数帯域／周波数でＰＦスケジューリング因子最大のユーザを選択してスケジューリングを行うことを示す。 In step 13, the second scheduler specifies a user m to be scheduled by calculating a PF scheduling factor of each user in the second frequency band / frequency according to the following equation (6). However, using the scheduling history information Tr _n (t, 1) of the user in the first frequency band / frequency, the average rate T _n (t−1, t−1) in the first frequency band / frequency until the scheduling time immediately before the user. Replaced 2).

The above formula indicates that the second scheduler performs scheduling by selecting a user having the maximum PF scheduling factor in the second frequency band / frequency at the current scheduling time.

上記式において、Tr_n(t,2)は、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、ｍは現在スケジューリング時刻に第２周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。上記式（７）において、第１周波数帯域／周波数でユーザのスケジューリング履歴情報Tr_n(t,1)を用いて、該ユーザの直前のスケジューリング時刻まで第１周波数帯域／周波数での平均レートT_n(t-1,2)を代えた。 In step 14, after scheduling of the second scheduler is completed, the scheduling history information of each user is updated in the second frequency band / frequency according to the following equation (7).

In the above equation, Tr _n (t, 2) represents scheduling history information up to the current scheduling time t of the nth user in the second frequency band / frequency, and Tr _n (t, 1) represents the first frequency band. / N indicates the scheduling history information of the nth user up to the current scheduling time t, and R _n (t, 2) indicates the instantaneous rate in the second frequency band / frequency of the nth user at the current scheduling time t. _Tc represents the size of the slide window for average rate statistics, m represents a user scheduled in the second frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, and N represents the total number of users. In the above equation (7), using the user's scheduling history information Tr _n (t, 1) in the first frequency band / frequency, the average rate T _{n in} the first frequency band / frequency until the scheduling time immediately before the user. (t-1,2) was replaced.

  The scheduling history information in the first and second frequency bands / frequency of each user is updated according to the repetition of the above formulas (5) and (7). The initial value of the user scheduling history information in the first and second frequency bands / frequency can be set by itself.

As can be seen from the above description, in the joint scheduling method according to the present embodiment, when a certain scheduling time t comes, scheduling is first performed in the first frequency band / frequency. Based on the scheduling result, scheduling history information Tr _n (t, 1) of each user is acquired in the first frequency band / frequency, and the numerical value is delivered to the second scheduler. In the second scheduler, the user's PF scheduling factor is calculated by replacing the average rate of the user with Tr _n (t, 1) in the second frequency band / frequency until the previous scheduling time by the PF algorithm. After the scheduling of the second scheduler is completed, the user's scheduling history information Tr _n (t, 2) is newly calculated in the first frequency band / frequency, and the numerical value is handed over to the first scheduler. When the scheduling period arrives, the PF algorithm calculates the user's PF scheduling factor in the first frequency band / frequency up to Tr _n (t, 2) until the previous scheduling time, and performs scheduling by calculating the user's PF scheduling factor. The first scheduler is used. By analogy in this way, each scheduler forms the parameter passing relationship shown in FIG. 11 between successive scheduling times, and this is referred to as a serial scheduling method. Here, the first scheduler performs scheduling in the first frequency band of 2 GHz, and the second scheduler performs scheduling in the second frequency band of 3.5 GHz.

  Based on the above joint scheduling method, this embodiment provides a joint scheduling apparatus correspondingly and applies it to the original scheduling improvement of the base station side scheduler in the carrier aggregation system. As shown in FIG. 5, the apparatus includes at least two schedulers and scheduling control means.

  The scheduler of at least two schedulers performs scheduling of users based on a scheduling factor calculated from a scheduling factor function including the first parameter at the time of independent scheduling, and after the completion of scheduling, the second parameter and before updating The first parameter is updated based on a history information update function including the first parameter. However, the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, and the second parameter is a scheduling result of the scheduler.

  The scheduling control means controls all the schedulers to perform user scheduling step by step in accordance with a delivery order of predetermined scheduling history information until scheduling of all schedulers is completed within one scheduling time. The delivery order is as follows: first scheduler → second scheduler → third scheduler →... → Lth scheduler → first scheduler, where L is the total number of schedulers included in the base station.

  However, user scheduling by each scheduler is performed according to the scheduling factor calculated from the scheduling factor function after changing the first parameter using scheduling history information received from the previous scheduler in the delivery order in the latest round. Done.

  However, after completion of scheduling in each frequency band / frequency, each scheduler changes the first parameter using the scheduling history information received from the previous scheduler in the delivery order in the latest round, and then The scheduling history information is acquired by updating the history information update function, and the updated scheduling history information is delivered to the next scheduler in the delivery order.

  As an example, the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler.

  As an example, the apparatus has two at least two schedulers, the first scheduler performs user scheduling in a first frequency band / frequency, and the second scheduler performs user scheduling in a second frequency band / frequency. Do.

  The scheduling control means further controls user scheduling of the first scheduler when each scheduling time arrives, and controls user scheduling of the second scheduler after the scheduling of the first scheduler is completed.

  The first scheduler calculates a PF scheduling factor of each user in the first frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the first frequency band / frequency. Is identified. However, when calculating the PF scheduling factor from the PF scheduling factor function, the average rate in the first frequency band / frequency until the scheduling time immediately before the user using the scheduling history information of the user in the second frequency band / frequency. The calculation is performed instead of. After the scheduling of the first scheduler is completed, the user's scheduling history information is updated with the history information update function in the first frequency band / frequency. In the calculation for updating, calculation is performed using the scheduling history information of the user in the second frequency band / frequency and changing the average rate in the first frequency band / frequency until the scheduling time immediately before the user. Then, the updated scheduling history information of the user is delivered to the second scheduler in the first frequency band / frequency after the update.

  The second scheduler calculates a PF scheduling factor of each user in the second frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the second frequency band / frequency. Is identified. However, when calculating the PF scheduling factor from the PF scheduling factor function, the average rate in the second frequency band / frequency until the scheduling time immediately before the user using the scheduling history information of the user in the first frequency band / frequency. The calculation is performed instead of. After the scheduling of the first scheduler is completed, the user's scheduling history information is updated with the history information update function in the second frequency band / frequency. In the calculation for updating, calculation is performed using the scheduling history information of the user in the first frequency band / frequency and changing the average rate in the second frequency band / frequency until the scheduling time immediately before the user. Then, the updated scheduling history information of the user is delivered to the first scheduler in the second frequency band / frequency after the update.

上記式において、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t-1,2)は、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までのスケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻に第１周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。 As an example, the first scheduler further updates the scheduling history information of each user in the first frequency band / frequency according to the following equation.

In the above equation, Tr _n (t, 1) represents scheduling history information up to the current scheduling time t of the nth user in the first frequency band / frequency, and Tr _n (t−1,2) is the second The scheduling history information of the nth user up to the (t-1) th scheduling time in the frequency band / frequency is shown, and R _n (t, 1) is the first frequency band / frequency of the nth user at the current scheduling time t. Where T _c is the size of the average rate statistics sliding window, j is the user scheduled in the first frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, N is the user Indicates the total number.

上記式において、Tr_n(t,2)は、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、Tr_n(t,1)は、第１周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、ｍは現在スケジューリング時刻に第２周波数帯域／周波数でスケジューリングされるユーザを示す。 The second scheduler further updates the scheduling history information of each user in the second frequency band / frequency according to the following equation.

In the above equation, Tr _n (t, 2) represents scheduling history information up to the current scheduling time t of the nth user in the second frequency band / frequency, and Tr _n (t, 1) represents the first frequency band. / N indicates the scheduling history information of the nth user up to the current scheduling time t, and R _n (t, 2) indicates the instantaneous rate in the second frequency band / frequency of the nth user at the current scheduling time t. M represents a user scheduled in the second frequency band / frequency at the current scheduling time.

<Second embodiment>
The joint scheduling method according to the present embodiment is applied to a base station of a carrier aggregation system. The base station includes L (L ≧ 2) schedulers. Each scheduler performs user scheduling in its own frequency band / frequency. The joint scheduling method according to the present embodiment improves the unique scheduling of the scheduler. The scheduler performs user scheduling based on a scheduling factor calculated from a scheduling factor function including the first parameter at the time of independent scheduling, and after the scheduling is completed, the second parameter and the first parameter before updating The first parameter is updated based on a history information update function including. However, the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, and the second parameter is a scheduling result of the scheduler.

  Specifically, in the joint scheduling method according to the present embodiment, within one scheduling time, user scheduling by each scheduler is performed by replacing the first parameter with the user's total scheduling history information received in the latest round. To the scheduling factor calculated from the scheduling factor function.

  However, after the scheduling of all schedulers is completed, the first parameter is changed using the user's total scheduling history information obtained in the latest update, and the second parameter is changed using the scheduling result of all schedulers. The user's overall scheduling history information is acquired by updating the history information update function, and the updated user's overall scheduling history information is delivered to each scheduler.

  Specifically, for a scheduler employing a PF algorithm, the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is an average rate of users in a frequency band / frequency corresponding to the scheduler. It is.

As can be seen from the above description, in this embodiment, a parallel scheduling scheme is adopted among the L schedulers of the base station, that is, when each scheduling time comes, each scheduler of the base station Perform scheduling based on the total scheduling history information, and after scheduling of all schedulers is completed, update the user's total history information based on the scheduling results of all schedulers and pass it to each scheduler to calculate the scheduling factor at the next scheduling time To serve. By passing the overall scheduling history information, a parallel connection is formed between the schedulers, and the delivery relationship of the overall scheduling history information in the case of L schedulers is shown in FIG. 12, and Ts _n (t, x) Refer to FIG. 13 for the meaning.

  In some cases, when the transmission delay between the schedulers becomes larger than one transmission time interval (TTI), the first scheduling is performed by the scheduler according to the above method and using the overall scheduling history information of the user received in the latest time. After changing the parameters, user scheduling is performed by calculating a scheduling factor from the scheduling factor function. At this time, the scheduling history information received in the latest round may be scheduling history information updated several times before the current scheduling time.

  Hereinafter, the above method will be further described by taking as an example a carrier aggregation system in which a base station has two schedulers, and the scheduler adopts a PF scheduling algorithm at the time of independent scheduling. The carrier aggregation system includes a first scheduler that performs user scheduling in a first frequency band / frequency and a second scheduler that performs user scheduling in a second frequency band / frequency. In the case of the scheduler employing the PF scheduling algorithm, the scheduling factor function is a PF scheduling factor function of the PF algorithm, and the first parameter is an average rate of users in a frequency band / frequency corresponding to the scheduler. Please refer to FIG. When applied to two schedulers, the joint scheduling method according to the present embodiment specifically includes the following steps 21 to 22 when each scheduling time comes.

  In step 21, the first and second schedulers calculate the PF scheduling factor of each user in the first frequency band / frequency and the second frequency band / frequency based on the proportional fair PF algorithm, respectively, and the first frequency band / frequency, Scheduling is performed by identifying users to be scheduled in the second frequency band / frequency. However, when calculating the PF scheduling factor from the PF scheduling factor function, the first and second schedulers use the user's total scheduling history information in the first and second frequency bands / frequency, and the scheduling time immediately before the user is calculated. The calculation is performed by changing the average rate in each frequency band / frequency.

  In step 22, after the scheduling of the first and second schedulers is completed, the user's total scheduling history information is updated with the history information update function in the first and second frequency bands / frequency. In the calculation for updating, using the user's pre-update general scheduling history information in the first and second frequency bands / frequency, the first frequency band / frequency until the scheduling time immediately before the user in the history information update function. And changing the second parameter in the history information update function using the scheduling results of the first scheduler and the second scheduler, and then updating the history information update function to change the first, second, The overall scheduling history information of the user in two frequency bands / frequency is obtained, and the updated overall scheduling history information is delivered to each scheduler.

In the prior art, the PF algorithm is expressed as the above expression (3) as one expression format. The present embodiment improves the PF algorithm and calculates the average in the kth frequency band / frequency until the scheduling time (t−1) immediately before the user when calculating the PF scheduling factor in one frequency band / frequency. The rate T _n (t−1, k) is not used, and T _n (t−1, k) is replaced with the user's total scheduling history information Ts _n (t−1) in the first and second frequency bands / frequency. To calculate.

上記式において、R_n(t,1)は、現在スケジューリング時刻にｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、R_n(t,2)は、現在スケジューリング時刻にｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、Ts_n(t-1)は、ｎ個目ユーザの第１、第２周波数帯域／周波数での総体スケジューリング履歴情報を示す。 Specifically, in step 21, the first scheduler calculates a PF scheduling factor according to the following equation (8) and identifies the user j to be scheduled, while the second scheduler performs PF scheduling according to the following equation (9). Factors are calculated to identify the user m to be scheduled.

In the above equation, R _n (t, 1) indicates the instantaneous rate in the first frequency band / frequency of the nth user at the current scheduling time, and R _n (t, 2) is n at the current scheduling time. The instantaneous rate in the second frequency band / frequency of the eye user is indicated, and Ts _n (t−1) indicates the overall scheduling history information in the first and second frequency bands / frequency of the nth user.

上記式において、Ts_n(t-1)は、第１、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までの総体スケジューリング履歴情報を示し、Ts_n(t)は、第１、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでの総体スケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻ｔに第１周波数帯域／周波数でスケジューリングされるユーザを示し、ｍは現在スケジューリング時刻ｔに第２周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。式（８）に基づき、反復計算することにより、更新後の、第１、第２周波数帯域／周波数でユーザの総体スケジューリング履歴情報を得ることができる。第１、第２周波数帯域／周波数でユーザの総体スケジューリング履歴情報の初期値については、自ら設定可能である。 In step 22, the scheduling history information of each user is updated in the first and second frequency bands / frequency according to the following equation (10).

In the above equation, Ts _n (t−1) represents the overall scheduling history information up to the t−1th scheduling time of the nth user in the first and second frequency bands / frequency, and Ts _n (t) is , Indicates the overall scheduling history information up to the current scheduling time t of the nth user in the first and second frequency bands / frequency, and R _n (t, 1) is the first of the nth user at the current scheduling time t. Indicates the instantaneous rate in the frequency band / frequency, R _n (t, 2) indicates the instantaneous rate in the second frequency band / frequency of the nth user at the current scheduling time t, and T _c is for average rate statistics Indicates the size of the sliding window, j indicates a user scheduled in the first frequency band / frequency at the current scheduling time t, and m indicates scheduling in the second frequency band / frequency at the current scheduling time t. 1 ≦ n ≦ N, where N is the total number of users. By performing the iterative calculation based on the equation (8), it is possible to obtain the user's total scheduling history information in the first and second frequency bands / frequency after the update. The initial value of the user's overall scheduling history information in the first and second frequency bands / frequency can be set by itself.

In the present embodiment, Expression (10), which is another expression form of Expression (10), can be obtained by converting Expression (10).

In this way, the first scheduler can calculate Ts _n (t, 1) according to the above equation (12), the first scheduler can calculate Ts _n (t, 2) according to the above equation (13), and then the equation ( 11), the updated overall scheduling history information can be calculated. Analogy in this way. The parameter passing relationship between schedulers is shown in FIG.

  Based on the parallel scheduling method, the present embodiment further provides a joint scheduling apparatus in the carrier aggregation system, and applies it to the original scheduling improvement of the base station scheduler. As shown in FIG. 7, the apparatus includes at least two schedulers and parameter updating means.

  The scheduler of at least two schedulers performs scheduling of users based on a scheduling factor calculated from a scheduling factor function including the first parameter at the time of independent scheduling, and after the completion of scheduling, the second parameter and before updating The first parameter is updated based on a history information update function including the first parameter. However, the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, and the second parameter is a scheduling result of the scheduler.

  However, each scheduler performs scheduling of users within one scheduling time after changing the first parameter using the user's total scheduling history information received in the latest round, and from the scheduling factor function. This is done according to the calculated scheduling factor.

  The parameter updating means replaces the first parameter by using the user's general scheduling history information obtained by the latest update after completion of scheduling of all schedulers within one scheduling time, and uses scheduling results of all schedulers. Then, after changing the second parameter, the user's overall scheduling history information is acquired by updating the history information update function, and the updated user's overall scheduling history information is delivered to each scheduler.

  As an example, the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler.

  As an example, the at least two base stations are two, the first scheduler performs user scheduling in the first frequency band / frequency, and the second scheduler performs user scheduling in the second frequency band / frequency.

  As an example, the apparatus further includes scheduling control means for controlling the first and second schedulers to perform user scheduling in their own frequency band / frequency when each scheduling time comes.

  The first scheduler calculates a PF scheduling factor of each user in the first frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the first frequency band / frequency. Is identified. However, when calculating the PF scheduling factor from the PF scheduling factor function, the user's scheduling history information is used in the first and second frequency bands / frequency, and the first frequency band / frequency in the first frequency band / frequency until the scheduling time immediately before the user. Calculation is performed by changing the average rate.

  The second scheduler calculates a PF scheduling factor of each user in the second frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the second frequency band / frequency. Is identified. However, when calculating the PF scheduling factor from the PF scheduling factor function, the user's scheduling history information is used in the first and second frequency bands / frequency, and the second frequency band / frequency is used until the scheduling time immediately before the user. Calculation is performed by changing the average rate.

  The parameter updating means further updates the overall scheduling history information of the user with the history information update function in the first and second frequency bands / frequency after completion of scheduling at the current scheduling time of the first and second schedulers. In the calculation for updating, using the user's pre-update general scheduling history information in the first and second frequency bands / frequency, the first frequency band / frequency until the scheduling time immediately before the user in the history information update function. And changing the second parameter in the history information update function using the scheduling results of the first scheduler and the second scheduler, and then updating the history information update function to change the first, second, The overall scheduling history information of the user in two frequency bands / frequency is obtained, and the updated overall scheduling history information is delivered to each scheduler.

上記式において、Ts_n(t-1)は、第１、第２周波数帯域／周波数でｎ個目ユーザのt-1個目スケジューリング時刻までのスケジューリング履歴情報を示し、Ts_n(t)は、第１、第２周波数帯域／周波数でｎ個目ユーザの現在スケジューリング時刻ｔまでのスケジューリング履歴情報を示し、R_n(t,1)は、現在スケジューリング時刻ｔにｎ個目ユーザの第１周波数帯域／周波数での瞬時レートを示し、R_n(t,2)は、現在スケジューリング時刻ｔにｎ個目ユーザの第２周波数帯域／周波数での瞬時レートを示し、T_cは平均レート統計用スライドウィンドウのサイズを示し、jは現在スケジューリング時刻ｔに第１周波数帯域／周波数でスケジューリングされるユーザを示し、ｍは現在スケジューリング時刻ｔに第２周波数帯域／周波数でスケジューリングされるユーザを示し、１≦ｎ≦Ｎ、Ｎはユーザ総数を示す。 As an embodiment, the parameter updating means further updates the scheduling history information of each user in the first and second frequency bands / frequency according to the following formula.

In the above equation, Ts _n (t−1) indicates scheduling history information up to the t−1th scheduling time of the nth user in the first and second frequency bands / frequency, and Ts _n (t) is The scheduling history information up to the current scheduling time t of the n-th user in the first and second frequency bands / frequency is shown, and R _n (t, 1) is the first frequency band of the n-th user at the current scheduling time t. / indicates the instantaneous rate of the frequency, R _n (t, 2) is the currently scheduled time t indicates the instantaneous rate in the second frequency band / frequency of the n th user, T _c is the average rate statistic for sliding window J represents a user scheduled in the first frequency band / frequency at the current scheduling time t, and m is scheduled in the second frequency band / frequency at the current scheduling time t. 1 ≦ n ≦ N, where N represents the total number of users.

  In the present invention, there is no restriction on the average rate update method employed in the first and second schedulers. That is, the average rate may be updated according to the above formula (2), or the average rate may be updated according to another method, both of which are applied to the present invention.

  Compared with the scheduling method of the traditional scheduler-specific scheduling, according to the above two embodiments of the present invention, more excellent performance can be obtained, and the following reasons can be considered (two schedulers are taken as an example). .

  Usually, the reference signal received power (RSRP) in the first frequency band / frequency of the user is different from the RSRP value in the second frequency band / frequency, but the two conventional schedulers schedule independently of each other. When scheduled in a manner, the user has a close probability of being scheduled in two frequency bands / frequency. On the other hand, in the two embodiments of the present invention, by improving the traditional PF scheduling algorithm and passing the scheduling result between schedulers, one scheduler combines the scheduling results of other schedulers when scheduling. In view of the above, it becomes possible for the user to be scheduled in a frequency band / frequency more suitable for himself / herself, and the different performance of the user can be fully utilized in each frequency band / frequency to obtain a higher system throughput.

Finally, through the system level simulation and verification, the performance of the two-scheduler unique scheduling according to the embodiment of the present invention and the conventional two-scheduler scheduling was compared to further prove the advantages of the technical plan according to the present invention. The system parameters in a specific simulation environment are shown in Table 1 below.

FIG. 8 shows a CDF (cumulative distribution function) curve of user throughput, curve 1 shows a conventional scheduling scheme of the prior art, curve 2 shows a serial scheduling scheme of the first embodiment of the present invention, and curve 3 These show the parallel scheduling system of 2nd Example of this invention. Table 2 below shows a comparison of the system average rate and the cell boundary rate by the two methods according to the present invention and the traditional unique scheduling method. From the simulation results, according to the method of the present invention, the gain improvement of about 20% can be seen in the system average rate even at the cell boundary rate.

  The above are only preferred embodiments of the present invention. For general engineers in the field, some modifications and modifications are possible on the premise that the principle of the present invention is not deviated. However, it will be understood that these modifications and modifications are also within the protection scope of the present invention.

Claims (16)

A joint scheduling method applied to a unique scheduling improvement of a base station side scheduler in a carrier aggregation system, wherein the base station includes at least two schedulers, and the scheduler includes a scheduling factor including a first parameter at the time of independent scheduling. User scheduling is performed based on a scheduling factor calculated from the function, and after completion of scheduling, the first parameter is updated based on a history information update function including the second parameter and the first parameter before update. However, the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, and the second parameter is a scheduling result of the scheduler.
In the joint scheduling method,
Until the scheduling of all the schedulers is completed within one scheduling time, all the schedulers perform user scheduling step by step according to the delivery order of predetermined scheduling history information, and the delivery order is the first scheduler → second scheduler → three. 1st scheduler → ... → Lth scheduler → 1st scheduler, where L is the total number of schedulers included in the base station,
However, user scheduling by each scheduler is performed according to the scheduling factor calculated from the scheduling factor function after changing the first parameter using scheduling history information received from the previous scheduler in the delivery order in the latest round. Done,
However, after completion of scheduling in each frequency band / frequency, each scheduler changes the first parameter using the scheduling history information received from the previous scheduler in the delivery order in the latest round, and then A method of acquiring scheduling history information by updating a history information update function, and transferring the updated scheduling history information to a next scheduler in the delivery order.   2. The scheduling factor function according to claim 1, wherein the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is an average rate of users in a frequency band / frequency corresponding to the scheduler. the method of. The base station includes two schedulers, the first scheduler performs user scheduling in a first frequency band / frequency, the second scheduler performs user scheduling in a second frequency band / frequency,
When each scheduling time comes
First, the first scheduler determines a user to be scheduled in the first frequency band / frequency by calculating a PF scheduling factor of each user in the first frequency band / frequency based on a proportional fair PF algorithm, where When calculating the PF scheduling factor from the PF scheduling factor function, the average rate in the first frequency band / frequency is changed up to the scheduling time immediately before the user using the scheduling history information of the user in the second frequency band / frequency. In the calculation for updating the scheduling history information of the user with the history information update function in the first frequency band / frequency after the scheduling of the first scheduler is completed, the second frequency band / frequency is calculated. User scheduling history information Thus, the calculation is performed by changing the average rate in the first frequency band / frequency until the scheduling time immediately before the user, and then the updated scheduling history information of the user in the first frequency band / frequency is updated to the second scheduler. Hand over to
The second scheduler then calculates a PF scheduling factor for each user in the second frequency band / frequency based on a proportional fair PF algorithm to identify users to be scheduled in the second frequency band / frequency, provided that When calculating the PF scheduling factor from the PF scheduling factor function, using the scheduling history information of the user in the first frequency band / frequency, the average rate in the second frequency band / frequency is replaced until the scheduling time immediately before the user. In the calculation for updating the user scheduling history information with the history information update function in the second frequency band / frequency after completion of the scheduling of the second scheduler, the first frequency band / frequency is calculated. User scheduling history information in The calculation is performed by changing the average rate in the second frequency band / frequency until the scheduling time immediately before the user, and the updated scheduling frequency information of the user in the second frequency band / frequency is then updated to the first. The method according to claim 2, wherein the method is delivered to a scheduler. Updating the user's scheduling history information in the first frequency band / frequency as described above is updating the scheduling history information of each user in the first frequency band / frequency according to the following equation:

In the above equation, Tr _n (t, 1) represents scheduling history information up to the current scheduling time t of the nth user in the first frequency band / frequency, and Tr _n (t−1,2) is the second The scheduling history information of the nth user up to the (t-1) th scheduling time in the frequency band / frequency is shown, and R _n (t, 1) is the first frequency band / frequency of the nth user at the current scheduling time t. Where T _c is the size of the average rate statistics sliding window, j is the user scheduled in the first frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, N is the user Indicates the total number
Updating the user's scheduling history information in the second frequency band / frequency is updating the scheduling history information of each user in the second frequency band / frequency according to the following equation:

In the above equation, Tr _n (t, 2) represents scheduling history information up to the current scheduling time t of the nth user in the second frequency band / frequency, and Tr _n (t, 1) represents the first frequency band. / N indicates the scheduling history information of the nth user up to the current scheduling time t, and R _n (t, 2) indicates the instantaneous rate in the second frequency band / frequency of the nth user at the current scheduling time t. 4. The method of claim 3, wherein m represents a user scheduled in the second frequency band / frequency at a current scheduling time, 1 ≦ n ≦ N, and N represents a total number of users. A joint scheduling apparatus applied to the unique scheduling improvement of a base station side scheduler in a carrier aggregation system, wherein the apparatus includes at least two schedulers and scheduling control means,
The scheduler of at least two schedulers performs scheduling of users based on a scheduling factor calculated from a scheduling factor function including the first parameter at the time of independent scheduling, and after the completion of scheduling, the second parameter and before updating The first parameter is updated based on a history information update function including the first parameter, wherein the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, The second parameter is the scheduling result of the scheduler,
The scheduling control means performs control so that all schedulers perform user scheduling step by step in accordance with a predetermined scheduling history information delivery order until scheduling of all schedulers is completed within one scheduling time. Second scheduler → third scheduler →... → Lth scheduler → first scheduler, where L is the total number of schedulers included in the base station,
However, user scheduling by each scheduler is performed according to the scheduling factor calculated from the scheduling factor function after changing the first parameter using scheduling history information received from the previous scheduler in the delivery order in the latest round. Done,
However, after completion of scheduling in each frequency band / frequency, each scheduler changes the first parameter using the scheduling history information received from the previous scheduler in the delivery order in the latest round, and then An apparatus characterized in that scheduling history information is acquired by updating a history information update function, and the updated scheduling history information is delivered to the next scheduler in the delivery order.   6. The scheduling factor function according to claim 5, wherein the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler. Equipment. The at least two schedulers are two, the first scheduler performs user scheduling in the first frequency band / frequency, the second scheduler performs user scheduling in the second frequency band / frequency, and
The scheduling control means further controls user scheduling of the first scheduler when each scheduling time arrives, and controls user scheduling of the second scheduler after the scheduling of the first scheduler is completed,
The first scheduler calculates a PF scheduling factor of each user in the first frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the first frequency band / frequency. However, when calculating the PF scheduling factor from the PF scheduling factor function, the scheduling frequency information of the user is used in the second frequency band / frequency, and the first frequency band / In the calculation for updating the user scheduling history information with the history information update function in the first frequency band / frequency after the completion of the scheduling of the first scheduler, the calculation is performed by changing the average rate at the frequency. , Second frequency band / frequency Then, the calculation is performed using the scheduling history information of the user by changing the average rate in the first frequency band / frequency until the scheduling time immediately before the user, and then the user is updated in the first frequency band / frequency after the update. The scheduling history information for the second scheduler,
The second scheduler calculates a PF scheduling factor of each user in the second frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the second frequency band / frequency. However, when the PF scheduling factor is calculated from the PF scheduling factor function, the scheduling frequency information of the user is used in the first frequency band / frequency, and the second frequency band / In the calculation for updating the user scheduling history information with the history information update function in the second frequency band / frequency after completion of the scheduling of the second scheduler, the calculation is performed by changing the average rate at the frequency. , 1st frequency band / frequency Then, using the scheduling history information of the user, the calculation is performed by changing the average rate in the second frequency band / frequency until the scheduling time immediately before the user, and then the user is updated in the second frequency band / frequency after the update. The apparatus according to claim 6, wherein the scheduling history information is transferred to the first scheduler. The first scheduler further updates the scheduling history information of each user in the first frequency band / frequency according to the following formula:

In the above equation, Tr _n (t, 1) represents scheduling history information up to the current scheduling time t of the nth user in the first frequency band / frequency, and Tr _n (t−1,2) is the second The scheduling history information of the nth user up to the (t-1) th scheduling time in the frequency band / frequency is shown, and R _n (t, 1) is the first frequency band / frequency of the nth user at the current scheduling time t. Where T _c is the size of the average rate statistics sliding window, j is the user scheduled in the first frequency band / frequency at the current scheduling time, 1 ≦ n ≦ N, N is the user Indicates the total number
The second scheduler further updates the scheduling history information of each user in the second frequency band / frequency according to the following formula:

In the above equation, Tr _n (t, 2) represents scheduling history information up to the current scheduling time t of the nth user in the second frequency band / frequency, and Tr _n (t, 1) represents the first frequency band. / N indicates the scheduling history information of the nth user up to the current scheduling time t, and R _n (t, 2) indicates the instantaneous rate in the second frequency band / frequency of the nth user at the current scheduling time t. 8. The apparatus of claim 7, wherein m represents a user scheduled in the second frequency band / frequency at a current scheduling time, 1 ≦ n ≦ N, and N represents a total number of users. A joint scheduling method applied to a unique scheduling improvement of a base station side scheduler in a carrier aggregation system, wherein the base station includes at least two schedulers, and the scheduler includes a scheduling factor including a first parameter at the time of independent scheduling. User scheduling is performed based on a scheduling factor calculated from the function, and after completion of scheduling, the first parameter is updated based on a history information update function including the second parameter and the first parameter before update. However, the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, and the second parameter is a scheduling result of the scheduler.
In the joint scheduling method,
Within one scheduling time, user scheduling by each scheduler is performed by a scheduling factor calculated from the scheduling factor function after replacing the first parameter using the user's total scheduling history information received in the latest round. ,
However, after the scheduling of all schedulers is completed, the first parameter is changed using the user's total scheduling history information obtained in the latest update, and the second parameter is changed using the scheduling result of all schedulers. A method of acquiring the user's total scheduling history information by updating the history information update function and transferring the acquired user's total scheduling history information to each scheduler.   10. The scheduling factor function according to claim 9, wherein the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler. the method of. The base station includes two schedulers, the first scheduler performs user scheduling in a first frequency band / frequency, the second scheduler performs user scheduling in a second frequency band / frequency,
When each scheduling time comes
The first and second schedulers calculate the PF scheduling factor of each user in the first and second frequency bands / frequency based on the proportional fair PF algorithm, respectively, and users to be scheduled in the first and second frequency bands / frequency However, when calculating the PF scheduling factor from the PF scheduling factor function, the first and second schedulers all use the user's total scheduling history information in the first and second frequency bands / frequency, and Until the scheduling time immediately before the calculation, the average rate in each frequency band / frequency is changed, and after the scheduling of the first and second schedulers is completed, the total number of users in the first and second frequency bands / frequency is calculated. Update scheduling history information with the history information update function and In the history information update function, the average rate in the first frequency band / frequency until the scheduling time immediately before the user is used in the history information update function using the user's pre-update aggregate scheduling history information in the first and second frequency bands / frequency. In addition, after changing the second parameter in the history information update function using the scheduling results of the first scheduler and the second scheduler, the first and second frequency bands / frequency are updated by updating the history information update function. The method according to claim 10, wherein the general scheduling history information of the user is obtained and the total scheduling history information obtained by updating is transferred to each scheduler. Updating the user's overall scheduling history information in the first and second frequency bands / frequency described above updates the scheduling history information of each user in the first and second frequency bands / frequency according to the following formula. The method of claim 11, wherein the method is characterized in that:

In the above equation, Ts _n (t−1) indicates scheduling history information up to the t−1th scheduling time of the nth user in the first and second frequency bands / frequency, and Ts _n (t) is The scheduling history information up to the current scheduling time t of the n-th user in the first and second frequency bands / frequency is shown, and R _n (t, 1) is the first frequency band of the n-th user at the current scheduling time t. / indicates the instantaneous rate of the frequency, R _n (t, 2) is the currently scheduled time t indicates the instantaneous rate in the second frequency band / frequency of the n th user, T _c is the average rate statistic for sliding window J represents a user scheduled in the first frequency band / frequency at the current scheduling time t, and m is scheduled in the second frequency band / frequency at the current scheduling time t. 1 ≦ n ≦ N, where N represents the total number of users. A joint scheduling device applied to improve the original scheduling of a base station side scheduler in a carrier aggregation system,
The apparatus includes at least two schedulers and parameter updating means,
The scheduler of at least two schedulers performs scheduling of users based on a scheduling factor calculated from a scheduling factor function including the first parameter at the time of independent scheduling, and after the completion of scheduling, the second parameter and before updating The first parameter is updated based on a history information update function including the first parameter, wherein the first parameter is user scheduling history information in a frequency band / frequency corresponding to the scheduler, The second parameter is the scheduling result of the scheduler,
However, each scheduler performing user scheduling within one scheduling time is calculated from the scheduling factor function after changing the first parameter using the user's total scheduling history information received in the latest round. Done by scheduling factors,
The parameter updating means replaces the first parameter by using the user's general scheduling history information obtained by the latest update after completion of scheduling of all schedulers within one scheduling time, and uses scheduling results of all schedulers. Then, after changing the second parameter, the user's overall scheduling history information is acquired by updating the history information update function, and the updated user's overall scheduling history information is delivered to each scheduler. .   14. The scheduling factor function according to claim 13, wherein the scheduling factor function is a PF scheduling factor function of a proportional fair PF algorithm, and the first parameter is a user average rate in a frequency band / frequency corresponding to the scheduler. Equipment. The at least two base stations are two, the first scheduler performs user scheduling in the first frequency band / frequency, the second scheduler performs user scheduling in the second frequency band / frequency,
The apparatus further includes scheduling control means for controlling the first and second schedulers to perform user scheduling in their own frequency band / frequency when each scheduling time comes,
The first scheduler calculates a PF scheduling factor of each user in the first frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the first frequency band / frequency. However, when calculating the PF scheduling factor from the PF scheduling factor function, the first frequency until the scheduling time immediately before the user is obtained using the user's scheduling history information in the first and second frequency bands / frequency. The calculation is performed by changing the average rate in the band / frequency,
The second scheduler calculates a PF scheduling factor of each user in the second frequency band / frequency based on the proportional fair PF algorithm according to the control of the scheduling control means, and schedules users in the second frequency band / frequency. However, when calculating the PF scheduling factor from the PF scheduling factor function, the second frequency up to the scheduling time immediately before the user is obtained using the user's scheduling history information in the first and second frequency bands / frequency. The calculation is performed by changing the average rate in the band / frequency,
The parameter updating means further updates the overall scheduling history information of the user with the history information update function in the first and second frequency bands / frequency after completion of scheduling at the current scheduling time of the first and second schedulers, and updates In the calculation for performing the first and second frequency bands / frequency using the user's pre-update general scheduling history information, the history information update function uses the first frequency band / frequency until the scheduling time immediately before the user. And changing the second parameter in the history information update function using the scheduling results of the first scheduler and the second scheduler, and then updating the history information update function to change the first, second, Obtain and update the user's overall scheduling history information in frequency band / frequency The apparatus of claim 14, the resulting overall scheduling history information, characterized in that passed to the scheduler. The apparatus according to claim 15, wherein the parameter updating means updates scheduling history information of each user in the first and second frequency bands / frequency according to the following formula.

In the above equation, Ts _n (t−1) indicates scheduling history information up to the t−1th scheduling time of the nth user in the first and second frequency bands / frequency, and Ts _n (t) is The scheduling history information up to the current scheduling time t of the n-th user in the first and second frequency bands / frequency is shown, and R _n (t, 1) is the first frequency band of the n-th user at the current scheduling time t. / indicates the instantaneous rate of the frequency, R _n (t, 2) is the currently scheduled time t indicates the instantaneous rate in the second frequency band / frequency of the n th user, T _c is the average rate statistic for sliding window J represents a user scheduled in the first frequency band / frequency at the current scheduling time t, and m is scheduled in the second frequency band / frequency at the current scheduling time t. 1 ≦ n ≦ N, where N represents the total number of users.

Images