JP2008502235A - Resource distribution and signal routing method in a centralized base station - Google Patents

Abstract

The present invention provides a method for allocating channel resources to a centralized BS, selecting an optimum channel processing device for each newly added radio link, and thereby associated with each newly added radio link. It can be concluded that all channel processing to be performed is performed by the corresponding optimum channel processing device. The present invention further provides a method for adaptively assigning resources and balancing the addition based on the end of channel resource allocation, and also provides a centralized base station capable of implementing the above-described channel resource allocation method. To do. Thus, each newly added radio link (which concludes a newly added and built link due to macro diversity) can be assigned to and processed by the optimal channel processor, thereby maximizing the use of channel processing resources. Is realized.
[Selection] Figure 6b

Description

  The present invention relates to the technical field of centralized base stations in mobile communication systems. In particular, the present invention relates to a resource allocation and control method in a centralized base station system using remote radio frequency units (RRU).

1. Centralized base station overview
In a mobile communication system, a base transceiver station (BTS) performs transmission, reception and processing of radio signals. A traditional BTS mainly consists of a baseband processing subsystem, an RF subsystem, and an antenna. As shown in FIG. 1A, one BTS covers different cells via multiple antennas. The BTS is connected to a base station controller (BSC) or a radio network controller (RNC) via an interface, respectively, as shown in FIG. An access network (RAN) is configured.

  FIG. 2 shows the system architecture of another centralized base station, i.e., a centralized base station using a remote radio frequency unit (RRU). Compared to traditional base stations, this centralized base station using RRU has many advantages. That is, a single macrocell based on a traditional base station can be replaced with multiple microcells, thereby being well adapted to different radio environments, capacitance, coverage area, other radio of the system With improved performance and such a centralized structure, soft handovers can be performed using softer handovers, thus obtaining more processing gain, such as Centralized structure allows expensive baseband signal processing resources to be resource pools shared by multiple cells, thereby multiplexing convenience and obtaining statistical results that effectively reduce system prices it can. International Patent Application No. WO9005432 (Invention Name “Communications System”), US Patent Application No. US5657374 (Invention Name “Cellular System with Centralized Base Stations and Distributed Antenna Units”) and US6324391 Specification (Invention name “Cellular Communication with Centralized Control and Signal Processing”), Chinese patent application CN1471331 (invention name “Mobile Communications Base Station System”), US patent application US20030171118 (invention) The names “Cellular Radio Transmission Apparatus and Cellular Radio Transmission Method”) all specify details of the relevant configuration of the technology.

  As shown in FIG. 2, a centralized base station system using RRU includes a central channel processing master unit (MU) 10 and a plurality of remote radio frequency units provided in a centralized manner. (RRU) 20, which are connected via a high bandwidth transmission link or network, while the BSC / RNC interface unit is a user plane and the signaling plane of the interface between the BTS and the BSC / RNC interface. Execute the process. The central channel processing master unit (MU) is mainly composed of a channel processing resource pool, a signal routing allocation unit, and other functional units. The channel processing resource pool is formed by stacking a plurality of channel processing units. Performing processing and other work, the signal routing allocation device dynamically allocates channel processing resources according to the traffic difference of each cell, so that the processing resources can be efficiently shared by multiple cells. In addition to being implemented within the MU as shown in FIG. 2, the signal routing assignment device can also be implemented outside the MU as a single device. The RRU is mainly composed of a transmission channel RF power amplifier, a reception channel low noise amplifier, an antenna and other functional devices. The link between the central channel processing master device 10 and the RRU typically uses fiber optic, copper cable, microwave, and other transmission media, and the signal transmission can take a digital signal after sampling or is modulated The analog signal may be a baseband signal, an intermediate frequency signal, or an RF signal.

  From the above overview of the prior art, the main advantage of a centralized base station is that it allows baseband signal processing resources to be a resource pool shared by multiple cells, thereby statistically multiplexing Is to obtain the benefits and efficiently reduce the system price. Therefore, a centralized base station key is a method of efficiently performing channel processing resource distribution.

2. Channel processing resources and centralized base stations
In code division multiple access (CDMA) systems, the baseband signal processing resources are primarily chip level processing units with other enhanced reception technologies such as RAKE receivers or multi-user detection (MUDD) as a core. The symbol level processing unit with the channel CODEC processing as the core, the symbol level processing is closely related to the user service type and rate relationship, while the chip level processing is less due to the user service type and rate relationship. Unaffected and mainly related to the number of service channels.

  In large scale base station systems that support multiple sectors and multiple carrier frequencies, the channel processing function section typically has two possible architectures, one of which is a chip level processor and a symbol level processor. Are integrated on a single board, that is, the system consists of a number of configurable multiple channel processing modules, the other being a chip-level processing unit and a symbol-level processing unit on different boards Each of the above is realized, that is, the system is composed of a plurality of chip level processing modules and symbol level processing modules which can be configured. 3 and 4 show typical structural examples of the two architectures described above.

  In a typical example of a system architecture formed by integrating a chip level processor and a symbol level processor as shown in FIG. 3, the system consists of M independent channel processing modules. So-called “independent” refers to these channel processing modules performing their respective channel processing tasks without any internal signal interconnections. Without internal signal interconnections, the design of the system backboard bus is greatly simplified, which allows the formation of large centralized base stations. Independence between modules does not lead to efficient utilization of system resources, but prior art solutions for baseband signal processing are formed by digital signal processors (DSPs) or arrays of multiple microprocessors for parallel processing. Based on the structure, it also has all software configuration solutions. The software flexibility in scheduling processor resources greatly reduces the architectural drawbacks associated with efficient use of system resources.

  In a typical system architecture example, the chip level processing unit and the symbol level processing unit are separated separately as shown in FIG. 4, and the system consists of P chip level processing modules and Q units. The chip level processing modules are independent of each other, i.e. they perform their respective chip level processing tasks without any internal signal interconnections. Chip-level processing speed is very high, so internal signal interconnections between chip-level processing modules complicate the system architecture and are difficult to apply in large-scale centralized base stations On the other hand, due to the relatively low speed, the symbol level processing module allows internal signal interconnections to share processing resources, so that the symbol level processing section is a continuous single processing module. Can be regarded.

  Thus, the two typical execution structures described above have the problem of channel processing resource discontinuities. On the other hand, in a large centralized base station, each channel processor has limited processing power, so when the RRU supported by the centralized base station is large, The simultaneous exchange of all RRU radio signals for each channel processor has no practical meaning. On the other hand, since radio signals have high data flow rates that are limited by the complexity of the signal routing assignment device and the system, simultaneous exchange of all radio signals of the RRU for each channel processor is difficult to implement. Therefore, the number of RRU signals that can be processed simultaneously by each channel processor is always limited, ie all radio signals corresponding to RRUs in a centralized base station are not necessarily exchanged to a channel processor at the same time. Is not possible.

Thus, according to the analysis of the exemplary channel processing system architecture shown in FIGS. 3 and 4, the problem of prior art channel processing resource distribution in the centralized base station is further summarized as the following questions: Can be done. That is,
-For each newly added radio link (including newly built links or links added for macro diversity), which channel processor should be distributed for processing and the radio link Is transmitted to the distributed channel processing device corresponding to the RRU of the cell to which the cell belongs.

  The foregoing channel processing apparatus for the channel processing system architecture shown in FIG. 3 corresponds to each channel processing module and corresponds to the chip level processing module of the channel processing system architecture shown in FIG. Yes. Since the symbol level processing section is a continuous, single processing module and does not have the aforementioned distribution problem, its internal resource scheduling is not considered in the present invention. In view of the above questions, the present invention describes an effective method.

  That is, one of the objects of the present invention is to provide a method for distributing channel resources in a centralized base station of a wireless communication system.

  The method of the present invention includes the step of selecting an optimum channel processing device for each newly added radio link, whereby the channel processing associated with each of the newly added radio links is corresponding. It is executed in the selected optimum channel processor.

In one embodiment of the channel resource distribution method described above, the following steps are further performed. That is,
According to the parameters associated with each newly added radio link in the access process, the amount of occupied resources of each newly added radio link is quantized using known system resource model information and newly added. For each radio link, a step of selecting an optimum channel processing device based on the amount of resources occupied by each newly added radio link obtained by the quantization is included.

  In a preferred execution mode according to the above-mentioned channel resource distribution method, the step of selecting an optimum channel device for each newly added radio link is performed on each radio link for which each selected optimum channel processing device is responsible for processing. This is done so that the corresponding cells are geographically neighboring and can be centralized as much as possible.

  Therefore, the selection of the optimal channel processor for each newly added radio link (including newly constructed links and links added by macro diversity) according to the method described above is now determined by the channel of the base station. An optimized distribution of processing resources can be realized. Based on this, medium-term or long-term statistical results of the channel processor load at the centralized base station to balance the channel processor processing load to maximize the use of channel processing resources Accordingly, it is further possible to perform resource scheduling between channel processing devices.

Therefore, yet another object of the present invention is to provide a method for adaptive resource scheduling and load balancing at a centralized base station of a wireless communication system, which method comprises:
According to the statistical result of the load of the channel processing unit in the centralized base station, the parameters related to the load sharing between the channel processing units of the system resource model information are adaptively adjusted, and thereby between the channel processing units Providing adaptive resource scheduling and load balancing,
An optimal channel processor is selected for each newly added radio link based on the amount of occupied resources determined for each newly added radio link, thereby each newly added radio link. The channel processing associated with the radio link is performed in a correspondingly selected optimum channel processing device.

  In the execution mode of the foregoing method for performing adaptive resource scheduling and load balancing of the present invention, the radio link that is responsible for processing by the optimal channel processor selected for each newly added radio link. The cells corresponding to are geographically neighboring and are centralized into one region as much as possible.

  According to a preferred mode of execution of the foregoing method for adaptive resource scheduling and load balancing, for each channel processor in the centralized base station, the cells under the control of the centralized base station have different resources. Partitioned into corresponding groups of cell sets having distribution levels, and an optimal channel processor is selected for each newly added radio link according to the resource distribution level of the cell sets partitioned from high to low. .

According to a further object of the present invention, there is provided a centralized base station for implementing the above-described channel resource distribution method of the present invention, the centralized base station comprising:
A central channel processing master unit MU;
A plurality of remote radio frequency units RRU each coupled to a central channel processing master unit MU via a high bandwidth transmission link or network;
The centralized base station further includes
For each newly added radio link, an optimal channel selection member is provided for selecting an optimal channel processing device, whereby the channel associated with each newly added radio link is selected correspondingly. It is executed in an optimum channel processing apparatus.

  In the above-described centralized base station execution mode according to the present invention, the optimal channel selection portion is newly quantized using known system resource model information for each newly added radio link. An optimum channel processing device is selected based on the resource occupancy of each added radio link. In a preferred execution mode, the optimal channel selection member is a region where the cells corresponding to the radio links for which each selected optimal channel processing device is responsible for processing are geographically close and as far as possible. It is configured to be able to be centralized.

  To illustrate the present invention, a CDMA system will be described as an example, but the basic idea, essence, principle and method of the present invention are other modes of mobile communication systems such as FDMA, TDMA, OFDM, etc. It is necessary to explain that it can be applied to.

  As explained, according to the present invention, the distribution of channel processing resources in a centralized base station is divided into two independent processing processes, one of which is added by a newly built link and macro diversity. Process of selecting the optimal channel processing device for each newly added radio link (including the added links), and the other is to achieve the goal of maximizing the use of channel processing resources. A process for performing resource scheduling between channel processors in accordance with the medium-term or long-term statistical results of the load on the channel processors in the centralized base station to balance the processing load. Clearly, the former processing process can achieve optimization of channel processing resource distribution in a centralized base station, the latter further improving the former.

The features and advantages of the present invention will become more apparent with reference to the detailed description of the drawings of specific embodiments of the invention.
Hereinafter, a detailed description of an embodiment of the present invention will be given with reference to the accompanying drawings.

1. Resource distribution in access processing According to the present invention, when a radio link (including newly built links and links added by macro diversity) is newly added, it is optimal to perform corresponding channel processing. It is necessary to select a channel processor. Therefore, it is necessary to analyze and evaluate the resource occupancy of newly added radio links, and according to the analysis, the system resources related to the centralized base station are mainly as follows.
・ Chip level processor resources,
Symbol level processor resources (only for channel processing system architectures as shown in FIG. 3),
• Channel resources of RRU radio signals that can be processed by each channel processor at the same time, that is, can be exchanged or transmitted to each channel processor at the same time.

  As mentioned above, radio links with different rates and for different service types occupy different chip-level processing resources and symbol-level processing resources, on the other hand, newly built radio links and macro diversity The links added by are also different in the occupation of system resources. Therefore, the amount of occupied resources of each newly added radio link is quantized according to the radio link parameters including rate, service type, and whether the radio link is added for macro diversity, etc. It is necessary to analyze and evaluate the degree. System resource model information including average resource occupancy of radio links in different types of services with different rates, channel processing resource structure, etc. is determined to be known to the base station Therefore, the selection of the optimum channel processing device for performing the corresponding channel processing is actually equivalent to the search operation.

  According to the present invention, the selection of the optimal channel processor for each newly added radio link (including newly constructed links and links added by macro diversity) must follow the following principles. In other words, the selection of the optimum channel processing device should occupy as little as possible the RRU signal channel resource of each channel processing device, and the RRU radio signal in the cell where the macro diversity branch exists is subjected to soft handover. When it occurs, it needs to be exchanged as much as possible to one and the same channel processing device in order to realize a softer handover, and is caused by a mobility process such as handover of a mobile terminal between different cells The handover operation across the channel processor must be reduced as much as possible.

  In fact, when the mobile communication system used supports soft handover technology, processing all macro diversity branches of one mobile terminal of one and the same channel processing device at the same time is one of the system processing resources. Helps reduce loss and improve coverage area, capacitance, and other wireless performance. If the mobile communication system used, such as a CDMA system in TTD mode, does not support soft handover technology, the mobile terminal moves between different cells for handover and performs channel processing for that radio link. When still running on one and the same channel processor, the movement of context information associated with mobile terminals between different channel processors can be reduced, the operation associated with the parameter structure and the new channel processor Operation can be reduced, thereby simplifying system complexity and improving system stability and reliability.

  In accordance with the foregoing principles, the preferred mode of operation of the present invention is that the optimal channel for each newly added radio link (including newly established links and links added by macro diversity) in the access process. A processing unit is selected, whereby the cells corresponding to the radio links for which each channel processing unit is responsible are geographically close and centered in as much area as possible, so that each channel processing unit's RRU signal channel When the soft handover is performed with the least amount of resources, the RRU radio signal in the cell where the macro diversity branch exists can be exchanged to one identical channel processor as much as possible. And thereby the mobile terminal hand between different cells It helps to reduce as much as possible a reduction in handover operation across the channel processor caused by mobility process like Ba.

  Specifically, selecting the optimal channel processing device for each newly added radio link (including newly constructed links and links added by macro diversity) in access processing according to the present invention A preferred execution mode for doing this is described below.

First, for each channel processor of the centralized base station, the cells under the control of the centralized base station are partitioned into corresponding groups of cell sets with different resource distribution levels and are not limited In the preferred execution mode, the cells are divided into three cell sets: a basic cell set, a candidate cell set, and a remaining cell set, and each channel processor first processes the service channel of the cells in that basic cell set; Thereafter, the service channels of the cells in the candidate cell set are processed, and finally the service channels of the cells in the remaining cell sets are processed. According to the present invention, the cell division needs to follow the following principle.
Each cell to which a centralized base station belongs must be in the basic cell set of one and only one channel processor, which is called the channel processor to which the cell belongs . Thus, the basic cell set of all channel processors has empty intersections and their unions are all cells belonging to a centralized base station.
A basic cell is a set of geographically neighboring cells, thereby helping each channel processor to occupy as little RRU signaling channel resources as possible, and macro diversity exists when soft handover is performed Allows RRU radio signals in a cell to be exchanged to one and the same channel processor as much as possible, thereby helping to realize a softer handover of the channel processor.
The cells in the candidate cell set of each channel processor are neighboring cells that are geographically close to the cells in the basic cell set of the channel processor; therefore, these are the geographical coverage areas of the basic cell set It is an enlarged part. With overlapping coverage areas, one cell can exist simultaneously in a candidate cell set of multiple channel processing devices. As will be described below, the cells in the candidate cell set are candidate cells for load sharing, i.e. one channel processing unit has redundant channel processing resources, while another channel processing is processed. The channel processing device can initially provide channel processing resources to the cells in its candidate cell set. If a candidate cell set of a channel processing device includes several cells of a basic cell set of another channel processing device, this channel processing device is called a channel processing device in the vicinity of these channel processing devices.
The remaining cell set is a set of cells belonging to the centralized base station other than the base cells and candidate cells of the centralized base station. Since the cells in the remaining cell set are farther away from the cell processed by the channel processor, they consume excessive RRU signaling channel resources and are difficult to implement a softer handover process. It is. Therefore, as will be explained below, the cells of the remaining cell set are an option for load sharing in the ultimate case.

  FIG. 5 shows a schematic diagram of the three cell sets described above. In one example, the centralized base station has a total of nine channel processors, each corresponding to the basic cell set shown in the D1, D2,... D9 region of FIG. The region is expanded to the E1, E2,..., E9 region shown in FIG. 5 with a corresponding candidate cell set, and each region includes a number of geographically neighboring cells. The basic cell set of all channel processors covers all the cells to the right of the centralized base station, and any cell has only one belonging channel processor, but one cell It will be appreciated that it may be simultaneous in the candidate cell sets of the channel processing devices.

  FIGS. 6a and 6b are flow charts illustrating the process of selecting the optimal channel processor for the centralized base station radio link in the preferred mode of operation according to the present invention. In the drawing, FIG. 6a is a schematic flow chart showing the selection process of the optimum channel processing device. As shown in FIG. 6a, in step S50, for each channel processing device of the centralized base station, the cells under the control of the centralized base station differ according to the method shown in FIG. In step S60, the optimum channel processing device is divided into corresponding groups of cell sets having resource distribution levels, and each newly added radio link is determined based on the resource distribution levels of the cell sets divided from high to low. In step S70, the result of the optimum channel selection process is returned, i.e. whether the optimum channel processor is properly selected for each newly added radio link. .

  FIG. 6b shows the detailed processing flow of steps S60 and S70 of FIG. 6a. The base station responds immediately after receiving a message (step S100) that a radio link is newly established or added from the BSC / RNC. Radio link resources using known system resource model information, taking into account the factors that cause message processing, radio link rate, service type, and other parameters, and taking into account new radio link creation and addition factors The occupation amount is quantized (step S110), the cell in which the radio link exists and the corresponding RRU signal are searched (step S120), and then the base station searches for the channel processing apparatus to which the cell in which the radio link exists belongs. (Chip level processor resource, symbol level processor resource, RRU radio signal channel It is determined whether or not necessary resources (including resources etc.) can be provided to the radio link (step S130). If the determination result in step S130 is “no”, that is, the channel processing apparatus to which it belongs is necessary. If the resource is not provided, the base station searches all channel processing devices whose candidate cell set includes the cell in which the radio link exists (step S140), and the corresponding channel processing device is changed from high to low. It is continuously determined whether the required resources can be provided to the radio link in the order of the available resource amounts (step S150), and if the determination result in step S150 is “no” That is, if all these channel processors still cannot provide the required resources, the base station Continuously determining whether the required resources can be provided to the radio link in the order of the available resource amounts from high to low (step S160) If still not found, the base station returns a message to the BSC / RNC that the radio link cannot be established or added, indicating that a failure has occurred as a result of insufficient processing resources (step S210). In the above resource determination, when a channel processing apparatus that satisfies the resource request is found, the subsequent determination is stopped, and then the base station determines whether or not the RRU radio signal of the cell in which the radio link exists is transmitted to the channel processing apparatus. (Step S170), and if not transmitted, the RRU radio signal is transmitted to the channel processor (step S180), so that the base station allocates and distributes the corresponding channel processing resources for the radio link. Configure, configure the corresponding channel processing resource for the radio link, update the resource state statistics of the corresponding channel processing device (S190), and send a message that the radio link has been successfully established or added to the BSC / Return to RNC (step S200).

  In the above selection process for the optimal channel processing unit for the radio link, the channel processing unit belonging to the cell in which the radio link exists is preferentially selected, thereby allowing RRU signaling channel resources for each channel processing unit. Facilitates as little occupancy as possible and allows RRU radio signals in cells where macro diversity is present to be exchanged to one and the same channel processor as much as possible, thereby further Prompt to implement soft handover processing, and consider the channel processing device in which the candidate cell set includes the cell in which the radio link exists for the same purpose when the belonging channel processing device has insufficient resources There is a need. This situation occurs mainly because the neighboring area of the basic cell of the channel processor to which it belongs has high traffic with a large number of active users, so that the neighboring channel processor has overloaded the channel processor to which it belongs. Need to share. In order to achieve load balancing among channel processing devices, the channel processing device having the minimum load can provide the required processing resources when a plurality of channel processing devices whose candidate cell sets include cells in which radio links exist. Only when the system has the ultimate case of higher traffic occurring in a wide area within a short period of time, non-neighboring channel processing devices perform load sharing processing.

  Execution mode adopted to achieve optimal channel processor selection for each newly added radio link (including newly built links and links added by macro diversity) in the access process Allows cells corresponding to the radio links that each channel processor is responsible for processing to be geographically close and centralized to as much area as possible. However, those skilled in the art will appreciate that this preferred mode of operation is not a limitation on the technical solution for selecting the optimal channel processor for the newly added radio link of the base station centralized according to the present invention. It should also be considered that other construction methods that can be envisaged by those skilled in the art without constructive efforts are within the scope of the present invention. For example, the method by which each channel processor is partitioned can have other options, and is valid as long as the corresponding partitioning method performs the aforementioned resource allocation optimization of the centralized base station.

2. Adaptive resource scheduling and load balancing
According to the present invention, based on the selection of the optimal channel processor for the radio link, the channel processor's load according to the medium and long-term statistical results of the load on the centralized base station channel processor. It is further possible to perform resource scheduling between channel processing devices to balance the processing load, thereby achieving the objective of maximizing the utilization of channel processing resources.

  Thus, the present invention further provides a method for achieving load balancing between channel processors. According to this method of the present invention, a cell set based on the load sharing purpose of the channel processing device, such as a candidate cell set in the preferred execution mode shown in FIG. It can be adaptively adjusted according to the medium and long term statistical results of the device load, thereby achieving the load balancing objective between the channel processors.

  In the first case of a preferred embodiment of the method according to the invention, the average load condition statistics of the centralized base station channel processor are taken (average of the channel processors within a certain time range. Load), and the overall average load of all channel processors is obtained through a mathematical average. If a channel processor has a load that exceeds the total average by a predetermined threshold, the channel processor candidate cell set in the vicinity of the channel processor is appropriately expanded and the cells added thereto Are the cells in the basic cell set of the channel processing device and are geographically close to the cells in the candidate cell set of the corresponding nearby channel processing device. The number of cells added to a candidate cell set for a nearby channel processing device also depends on the respective load amount, that is, the larger the load amount that a neighboring channel processing cell has, the fewer cells are added to that candidate cell set. On the other hand, the smaller the load amount of the neighboring channel processing cell, the more cells are added to the candidate cell set, while the candidate cell set of the channel processing device is appropriately reduced and the number of cells to be subtracted. In accordance with the load amount of each channel processing device, that is, the larger the load amount of a channel processing device in the vicinity of the channel processing device, the more the channel processing device candidate cell set is subtracted and the basic cell of the neighboring channel processing device. A small number of cells belong to a set, while a channel in the vicinity of a channel processing unit. As the load amount tunnel processing unit has a small, subtracted from the candidate cell set of channel processors, cells belonging to the basic cell set of channel processors in the vicinity increases.

  FIG. 7A is a schematic diagram showing the first case. As shown in FIG. 7A, a centralized base station includes three channel processing devices A, B, and C corresponding to the basic cells A, B, and C, respectively. If channel processor B has a load that exceeds the total average by a predetermined threshold, based on the preferred solution described above, the candidate cell sets of its neighboring channel processors A and C are expanded, On the other hand, if the candidate cell set of the channel processing device B is reduced and the load of the channel processing device A is larger than the load of the channel processing device C, the expanded amount of the candidate cell set of the channel processing device A is the channel processing device. The number of cells belonging to the basic cell set of the channel processing device C, which is smaller than the amount of the candidate cell set of C and subtracted from the candidate cell set of the channel processing device B, is greater than the number of cells belonging to the basic cell set of the channel processing device C.

  In the second case of the preferred embodiment of the method according to the invention, the average load condition statistics of the centralized base station channel processor are taken (by the average of the channel processors within a certain time range. The load amount and the total average load amount of all channel processing devices are obtained (this is the same as the processing in the first case). If a channel processor has a load less than the total average by a predetermined threshold, the channel processor candidate cell set is expanded appropriately. The number of cells to be added depends on the load amount of each neighboring channel processing device, that is, the larger the load amount that a neighboring channel processing cell of the channel processing device has, the more the added cell cell candidate cell set. The number of cells belonging to the basic cell set of the neighboring channel processing device is small, and the smaller the load amount of the neighboring channel processing device with the channel processing device is, the smaller the load is added to the candidate cell set of the channel processing device. There are many cells belonging to the basic cell set of the processing apparatus. On the other hand, the candidate cell set of the channel processing device in the vicinity of the channel processing device is appropriately reduced, and the number of subtracted cells also depends on the load amount of each neighboring channel processing device, that is, the neighboring channel processing device has. The larger the load amount, the more cells are subtracted from the candidate cell set. On the other hand, the smaller the load amount of the neighboring channel processing device is, the fewer cells are subtracted from the candidate cell set.

  FIG. 7B is a schematic diagram showing the second case. A centralized base station comprises three channel processors A, B, C corresponding to basic cells A, B, C, respectively. If the channel processor B has a lower total load than the total average by a predetermined threshold, the channel processor A in the vicinity of the channel processor B and The candidate cell set for C is reduced, while the candidate cell set for channel processor B is expanded. If the load on the channel processing device A is smaller than the load on the channel processing device C, the reduced amount of the candidate cell set of the channel processing device A is smaller than the amount of the candidate cell set of the channel processing device C, and the channel processing device The number of cells added to the B candidate cell set and belonging to the basic cell set of the channel processing device A is greater than the number of cells belonging to the basic cell set of the channel processing device C.

  Those skilled in the art, in the adaptive resource scheduling and load balancing method as described above of the present invention, the parameter for determining the degree of load of the channel processing device is in addition to the total average load amount of all the channel processing devices, It will be further understood that all weighted average loads of all channel processors or other suitable parameters such as a function of the total average loads of all channel processors, eg, aP + b, may be included. Here, a and b are constants, and P is the total average load amount of all the processing apparatuses. Regarding the threshold value used when determining whether the load of a channel processing device needs to be adjusted, this can also be set by a person skilled in the art according to the actual situation.

  The above two methods of the present invention are preferably implemented by software, but obviously these methods can also be implemented by various hardware modules or structures well known to those skilled in the art. Therefore, hardware structures for implementing the above-described methods of the present invention using known hardware structures or combinations thereof can also be considered to be within the scope of the present invention. For example, in a centralized base station, it is possible to set a corresponding optimized channel processor selection member for selecting an optimal channel processor for newly added radio links, thereby centralizing Optimized distribution of resources at the selected base station. The optimal channel processor selection member can be realized by various well-known functional modules, which are given, for example, in the MU 10 shown in FIG. 3 or external to the centralized base station It can be easily understood that it can be provided.

  The technical solution of the present invention has been described above with the embodiments. However, those skilled in the art can make various improvements or modifications to the present invention without departing from the principle and technical scope of the present invention. The technical scope of the present invention is determined only by the claims.

Schematic of traditional BTS architecture and traditional radio access network architecture. 1 is a schematic diagram of a system architecture of a centralized base station using RRU. FIG. 1 is a schematic diagram of a system architecture of a prior art base station system in which a chip level processor and a symbol level processor are integrated into a channel processing function section. 1 is a schematic diagram of a system architecture of a prior art base station system in which a chip level processor and a symbol level processor are separated in a channel processing function section. FIG. 2 is a schematic diagram of three cell sets of a channel processing device in a centralized base station according to an embodiment of the present invention. 1 is a flowchart of a process for selecting an optimal channel processor for a centralized base station radio link according to one embodiment of the invention. FIG. 6a is a detailed flowchart of a process for selecting an optimal channel processing device, as shown in FIG. 6a. FIG. 3 is a schematic diagram of a first case and a second case of an embodiment of a method for adaptive scheduling and load balancing of channel processing resources according to the present invention.

Claims (32)

In a method for channel resource distribution in a centralized base station of a wireless communication system,
Selecting an optimum channel processing device for each newly added radio link, whereby the channel processing associated with each newly added radio link is selected correspondingly; Method performed in the device.   Quantize the amount of resources occupied by each newly added radio link using known system resource model information according to the parameters associated with each newly added radio link in the access process, and 2. The method of claim 1, further comprising: selecting an optimum channel processing device for each radio link based on an amount of resources occupied by each newly added radio link obtained by the quantization. To perform channel resource distribution.   The step of selecting an optimal channel device for each newly added radio link includes the step of selecting a cell corresponding to the radio link for which each selected optimal channel processing device is responsible for processing a geographically neighboring cell. The channel resource distribution method according to claim 1 or 2, wherein the channel resource distribution is performed so as to be centralized in one region as much as possible. The step of selecting an optimal channel processing device for each newly added radio link comprises the steps of:
For each channel processor of the centralized base station, the cells under the control of the centralized base station are partitioned into corresponding groups of cell sets with different resource distribution levels;
According to the resource distribution level of the cell set divided from high to low, the optimum channel processing device is selected for each newly added radio link, and the preferential selection is made in the cell set having a high resource distribution level. Including sub-steps of continuously selecting the channel processor in a cell set having a lower resource distribution level only when an optimal channel processor is not found in the cell set having a higher resource distribution level. The method for performing channel resource distribution according to any one of claims 1 to 3.   A cell set having different resource distribution levels partitioned for each channel processing device includes a basic cell, candidate cells, and remaining cells, the basic cell being unique to each processing device, The basic cell set of the channel processing device has an empty intersection, and for each cell of the basic cell set, there is a union which is all cells belonging to a centralized base station, and the channel processing device to which the cell belongs The channel processing device to which the cell belongs, and the cells in the candidate cell set of each channel processing device are neighboring cells that are geographically close to the cells of the basic cell set of the channel processing device, and the remaining cell sets Is a set of cells belonging to a centralized base station other than basic cells and candidate cells, and the resource distribution level is changed from high to low for each channel processing device. Serial basic cell, the candidate cell, a method of performing channel resource distribution of sequentially allocated according to claim 4, wherein the remaining cells. The step of selecting an optimal channel processing device for each newly added radio link according to the resource distribution level of the cell set partitioned from high to low,
After receiving a message to newly attach a radio link from the BSC / RNC, the base station occupies the cell where the radio link is located and the corresponding RRU radio signal from the newly added radio link obtained from the quantization. Based on the amount of resources,
The channel processing apparatus to which the cell belongs determines whether or not the required resource can be provided to the radio link, and if the channel processing apparatus to which the cell belongs cannot provide the required resource, the radio link Search for all channel processing devices whose candidate cell set contains the located cell, and the corresponding channel processing device has the required resources in the order of available resource amounts from high to low If all these channel processing devices still cannot provide the required resources, other channel processing devices can use the amount of resources available from high to low. In sequence, it is continuously determined whether the required resources can be provided to the radio link, so that the newly added Method of performing claims 4 or 5 channel resource distribution according optimal channel processor for the link. At the time of each determination of the resource allocation step, as long as a channel processing device satisfying the resource request is found, the subsequent determination is stopped, and if the optimal channel processing device satisfying the request is still not found in the resource allocation step, The centralized base station sends back a message that the radio link could not be established or added to the corresponding BSC / RNC, indicating that the failure resulted from insufficient processing resources;
After a channel processing device satisfying the resource requirement is obtained in the resource distribution step, it is determined whether or not the RRU radio signal of the cell in which the radio link exists is transmitted to the optimum channel processing device. , Direct the RRU radio signal to the optimal channel processor, then distribute and configure the corresponding channel processing resources to the radio link, update the statistical information of the resource status of the corresponding channel processor, and establish the radio link The method for performing channel resource distribution according to claim 6, wherein a message indicating that the addition is successful is returned to the BSC / RNC.   Resources that can be given to the newly added radio link to which the optimal channel processing device corresponds include chip level processing device resources, symbol level processing device resources, and RRU radio signal channel resources. The method of performing channel resource distribution according to any one of claims 1 to 7.   The parameters used in the step of quantizing the amount of resources occupied by each newly added radio link include the rate, service type, and radio link parameters of each newly added radio link. 8. A method for performing channel resource distribution according to any one of claims 7 to 9.   The channel resource according to claim 9, wherein the radio link parameter includes a type parameter indicating whether the newly added radio link is a radio link added by macro diversity or a newly constructed radio link. How to make a distribution.   When an optimal channel processing device is selected for a newly added radio link during the resource distribution step, there are a plurality of channel processing devices whose candidate cell set includes a cell in which the radio link is located. When a plurality of channel processing devices can provide necessary processing resources, a channel processing device having a minimum load is used as the optimum channel processing device in order to achieve load balancing among the channel processing devices. The method for performing channel resource distribution according to any one of claims 5 to 7. In a method for scheduling and load balancing adaptive resources at a centralized base station of a wireless communication system,
In accordance with the statistical result of the load of the channel processing unit in the centralized base station, the parameters related to the load sharing between the channel processing units of the system resource model information are adjusted so as to match, thereby, Realizing adaptive resource scheduling and load balancing of
An optimal channel processor is selected for each newly added radio link based on the amount of occupied resources determined for each newly added radio link, and thereby the newly added A method in which the channel processing associated with each radio link is performed in a correspondingly selected optimal channel processing device.   The cell corresponding to the radio link for which the optimal channel processor selected for each newly added radio link is responsible for processing is located geographically in the vicinity and is centralized in one region as much as possible. 13. A method for scheduling and load balancing adaptive resources according to claim 12. For each channel processor of the centralized base station, the cells under the control of the centralized base station are partitioned into corresponding groups of cell sets with different resource distribution levels,
14. The adaptive resource scheduling according to claim 12 or 13, wherein an optimal channel processor is selected for each newly added radio link according to the resource distribution level of the partitioned cell set from high to low. And how to do load balancing. Cell sets having different resource distribution levels partitioned for each channel processing device include a basic cell set, a candidate cell set, and a remaining cell set,
The basic cell set is unique to each processing device, and the basic cell set of all channel processing devices has an empty intersection, and for each cell of the basic cell set, all cells belonging to a centralized base station The channel processing device having a certain union and to which the cell belongs is the channel processing device to which the cell belongs, and the cells in the candidate cell set of each channel processing device are geographically relative to the cells of the basic cell set of the channel processing device. And the remaining cell set is a set of cells belonging to a centralized base station other than the basic cell and the candidate cell, and each channel processing device has a resource distribution level in the order from high to low. 15. The adaptive resource scheduling and load balancing of claim 14 assigned to said basic cell, said candidate cell, and said remaining cell, respectively. Way to do. Adjusting the parameters associated with the load sharing channel processor in the system resource model information to fit
Compare the load of one channel processing device with a predetermined value,
16. The adaptive resource scheduling according to any one of claims 12 to 15, including a sub-step for adjusting a parameter related to load sharing of the channel processing device to adapt based on the comparison result. And how to do load balancing. The predetermined value is:
Takes statistics of the instantaneous load status of the centralized base station channel processor, obtains the average load of the channel processor over a range of time, and obtains it by the mathematical average of the obtained average loads The weighted total average load of all the channel processing devices obtained by taking the total average load amount of all the channel processing devices as the predetermined value and executing the weighting processing of the obtained average load amount Is obtained by at least one of the methods of taking a quantity as the predetermined value and taking the function aP + b of the total average load of all processing devices as the predetermined value, wherein a and b are constants, 17. The method of adaptive resource scheduling and load balancing according to claim 16, wherein P is the total average load of all channel processors.   The adaptive resource scheduling and load balancing according to any one of claims 15 to 17, wherein the parameter associated with load sharing of the channel processors is the size of the corresponding cell set of each of the channel processors. How to do.   If the channel processing device has a load larger than the predetermined value, the candidate cell set of one or more nearby channel processing devices of the channel processing device is appropriately expanded, while the candidate cell of the channel processing device 19. A method for scheduling and load balancing adaptive resources according to any one of claims 16-18, wherein the set is appropriately reduced.   The cell added when the load amount of the channel processing device is larger than the predetermined value is a cell in the basic cell set of the channel processing device, and in the candidate cell set of the corresponding nearby channel processing device. 20. The method for performing adaptive resource scheduling and load balancing as claimed in claim 19, wherein the cell is geographically adjacent to the cell.   When the load amount of the channel processing device is larger than the predetermined value, the number of cells added to the candidate cell set of the channel processing device in the vicinity of the channel processing device is the load amount of each of the neighboring channel processing devices. In other words, the larger the load amount of the neighboring channel processing device is, the fewer cells are added to the candidate cell set, and the smaller the load amount of the neighboring channel processing device is, the smaller the candidate cell is. 21. A method for scheduling and load balancing adaptive resources according to claim 19 or 20, wherein the set is loaded with more cells.   When the load amount of the channel processing device is larger than the predetermined value, the amount that is appropriately reduced in the candidate cell set of the channel processing device depends on the load amount of the channel processing device in the vicinity of the channel processing device. In other words, the larger the load amount of a nearby channel processing device with a channel processing device, the smaller the number of cells that are subtracted from the candidate cell set of the channel processing device and belong to the basic cell set of the nearby channel processing device, The number of cells belonging to a basic cell set of a neighboring channel processing device increases as the load amount of the neighboring channel processing device having the channel processing device is smaller, which is subtracted from the candidate cell set of the channel processing device. Scheduling and load balancing of adaptive resources according to any one of How to do.   When the load amount of the channel processing device is smaller than the predetermined value, the candidate cell set of the channel processing device is appropriately expanded, while the candidate cells of one or more nearby channel processing devices of the channel processing device 19. A method for scheduling and load balancing adaptive resources according to any one of claims 16-18, wherein the set is appropriately reduced.   When the load amount of the channel processing device is smaller than the predetermined value, the number of cells added to the candidate cell set of the channel processing device depends on the load amount of each neighboring channel processing device, ie As the load amount of a nearby channel processing device having a channel processing device increases, a smaller number of cells are added to the candidate cell set of the channel processing device and belong to the basic cell set of the neighboring channel processing device. 24. The adaptive resource scheduling according to claim 23, wherein the smaller the load amount of the neighboring channel processing device is, the more cells are added to the candidate cell set of the channel processing device and belong to the basic cell set of the neighboring channel processing device. And how to do load balancing.   When the load amount of the channel processing device is smaller than the predetermined value, the reduced amount of the candidate cell set of the channel processing device in the vicinity of the channel processing device is also the load amount of the channel processing device in the vicinity. In other words, the larger the load amount of the neighboring channel processing device is, the more cells are subtracted from the candidate cell set, and the smaller the load amount of the neighboring channel processing device is, the smaller the subtraction amount is from the candidate cell set. 25. A method for scheduling and load balancing adaptive resources according to claim 23 or 24, wherein cells are reduced. In a centralized base station,
Central channel processing master device MU (10),
A plurality of remote radio frequency units RRU (20) each coupled to a central channel processing master unit MU via a broadband transmission link or network;
The centralized base station further includes
An optimal channel selection member for selecting an optimal channel processing device for each newly added radio link, whereby the channel processing associated with each newly added radio link is correspondingly A centralized base station that runs in the selected optimal channel processor.   The optimal channel selection member is determined for each newly added radio link based on the amount of resources occupied by each of the newly added radio links quantized using known system resource model information. 27. The centralized base station of claim 26, configured to select an optimal channel processor.   The optimal channel selection member makes the cells corresponding to the radio link for which each selected optimal channel processing device is responsible for processing geographically close and centralizes it in one region as much as possible. 28. A centralized base station according to claim 26 or 27, configured to allow The optimum channel selection member is:
A cell set partitioning sub-member for partitioning cells under control of the centralized base station into corresponding groups of cell sets having different resource distribution levels for each channel processing unit of the centralized base station;
According to the resource distribution level of the cell set divided from high to low, select the optimum channel processing device for each newly added radio link, make a preferential selection in the cell set having a high resource distribution level, A channel selection sub-member that continuously selects the optimum channel processor in a cell set having a low resource distribution level only when no optimum channel processor is found in the cell set having a high resource distribution level; 29. A centralized base station according to any one of claims 26 to 28.   A cell set having different resource distribution levels divided for each channel processing device includes a basic cell set, a candidate cell set, and a remaining cell set, and the basic cell is unique to each processing device, and all channels. The basic cell set of the processing device has an empty intersection, and for each cell of the basic cell set, there is a union which is all cells belonging to a centralized base station, and the channel processing device to which the cell belongs is a cell Cells in the candidate cell set of each channel processing device are neighboring cells that are geographically close to the cells of the basic cell set of the channel processing device, and the remaining cell sets are the basic cell and A set of cells belonging to a centralized base station other than the candidate cells, and the resource distribution level of each channel processor from high to low Serial basic cell, the candidate cell, centralized base station of claim 29, wherein assigned to the remaining cells. The channel selection sub member is:
If a cell belonging channel processing apparatus corresponding to a newly added radio link determines whether the required resource can be provided to the radio link, and if the channel processing apparatus to which the cell belongs cannot provide the required resource Search for all channel processing devices whose candidate cell set includes the cell where the radio link is located, and the corresponding channel processing devices need the resources in order of available resources from high to low If all these channel processing devices still cannot provide the required resources, other channel processing devices can be used from high to low. Continuously determining whether the required resources can be provided to the radio link in the order of the appropriate resource amount, Lay appended centralized base station of claim 29 or 30, wherein being configured to obtain an optimal channel processor for the wireless link. The channel selection sub-member further includes:
At each decision during the resource allocation process, as long as a channel processor satisfying the resource request is found, the subsequent determination is stopped, and if the optimum channel processor satisfying the request is still not found in the resource allocation step, The centralized base station returns a message that the radio link could not be established or loaded to the corresponding BSC / RNC, indicating that the failure originated from insufficient processing resources and fulfills the resource requirement After the channel processor is obtained in the resource distribution process, it is determined whether or not the RRU radio signal of the cell in which the radio link exists is transmitted to the optimum channel processor, and if not, the RRU radio is transmitted. The signal is transmitted to the optimal channel processor and then the corresponding channel processing resource Distributed to the radio link, updated the statistical information of the resource status of the corresponding channel processing device, and configured to return a message to the BSC / RNC that the radio link has been established or added appropriately 32. The centralized base station of claim 31.

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