CN106937302A - A method and device for determining LTE-TDD cell service support capacity - Google Patents

Abstract

The invention discloses a method and a device for determining the service support capacity of an LTE-TDD cell. According to the number of available downlink RBs, the average number of downlink RBs occupied by each VoLTE service, and the first impact factor, users who can support VoLTE services on PDSCH are determined. number; according to the number of available uplink RBs, the average number of uplink RBs occupied by each VoLTE service, and the second impact factor, determine the number of users that PUSCH can support VoLTE services; according to the number of REs in each VoLTE service cycle, the average CCE aggregation degree and the third impact factor to determine the number of users that the PDCCH can support for scheduling VoLTE uplink services and the number of users for scheduling VoLTE downlink services. The embodiment of the present invention provides a method and device for determining the service support capacity of an LTE-TDD cell, which is of great significance for overall network planning and service development strategies.

Description

A method and device for determining LTE-TDD cell service support capacity

technical field

The present invention relates to the technical field of mobile communication, in particular to a method and device for determining the service support capacity of an LTE-TDD (Time Division Long Term Evolution, long-term evolution based on Time Division Duplex) cell.

Background technique

VoLTE (Voice over LTE, voice solution carried by LTE) is a voice service based on IMS (IP Multimedia Subsystem, multimedia subsystem), which can realize the unification of data and voice services under the same network. As an emerging voice solution, VoLTE belongs to VoIP (Voice over Internet Protocol) technology. It is carried and realized through LTE (Long Term Evolution, Long Term Evolution) network, and will gradually replace mainstream voice solutions. GSM (Global System for Mobile Communication, Global System for Mobile Communications) and CSFB (Circuit Switched Fallback). Therefore, it is of great significance to accurately evaluate the support capacity of LTE cells for VoLTE services for overall network planning and service development strategies.

For the supportable capacity of a cell in a packet domain network represented by LTE technology, the network utilization rate, the statistics of the maximum number of access users or the number of active users are generally used as a measurement solution. Since the capacity of the packet domain service depends on the spectrum efficiency and is mutually restricted and influenced by different service quality requirements, wireless resources, network configuration, wireless environment, feature functions and other factors, network utilization, maximum number of access users or activation The statistics of the number of users can only evaluate the user capacity supported by LTE cells from the perspective of network load, and cannot provide a relatively specific number of users that can be supported for specific services.

To sum up, the supportable capacity of the existing LTE cells cannot be used as a method to measure the support capacity of VoLTE services, and due to the particularity of the LTE-TDD network in the time domain, VoLTE services under the LTE-TDD network have not yet been widely used , so there is no method for accurately evaluating the VoLTE service support capacity of the LTE-TDD cell for the time being.

Contents of the invention

The present invention provides a method and device for determining the service support capacity of an LTE-TDD cell to solve the problem in the prior art that there is no method for accurately evaluating the VoLTE service support capacity of the LTE-TDD cell.

A method for determining the service support capacity of an LTE-TDD cell in an embodiment of the present invention includes:

Determine the number of users that PDSCH (Physical Downlink Shared Channel, downlink physical shared channel) can support VoLTE service according to the number of available downlink RB (Resource Block, resource block), the average number of downlink RB occupied by each VoLTE service, and the first impact factor U _PDSCH ;

According to the number of uplink available RBs, the average number of uplink RBs occupied by each VoLTE service and the second impact factor, determine the number of users U _PUSCH that PUSCH (Physical Uplink Shared Channel, uplink physical shared channel) can support VoLTE services;

According to the number of resource units RE in each VoLTE service cycle, the average CCE (Control ChannelElement, control channel unit) aggregation degree of the cell and the third impact factor, it is determined that PDCCH (Physical Downlink ControlChannel, downlink physical control channel) can be used to schedule VoLTE The number of users _{UPDCCH_UL} for uplink services and the number of users _{UPDCCH_DL} for scheduling VoLTE downlink services;

According to the _UPDSCH , the _UPUSCH , the _{UPDCCH_UL} and the _{UPDCCH_DL} , determine the VoLTE service support capacity of the LTE-TDD cell.

Optionally, according to the number of downlink available resource blocks RB, the average number of downlink RBs occupied by each VoLTE service, and the first impact factor, determining the number of users U _PDSCH that can support the VoLTE service on the downlink physical shared channel PDSCH includes:

Determine the number of users U _PDSCH that the PDSCH can support VoLTE services according to the following formula:

in, is the number of RBs available for the downlink, is the average number of downlink RBs occupied by each VoLTE service, For each VoLTE service cycle TTI (Transmission Time Interval, transmission time interval) quantity, the first impact factor includes: retransmission factor F _Retrans , downlink TDD (Time DivisionDuplexing, time division duplex) factor Voice Activation Factor VAF.

Optionally, the average number of downlink RBs occupied by each VoLTE service Determined according to the following formula:

Among them, M is the maximum number of downlink RBs that can be allocated in an LTE-TDD cell; i is the number of RBs corresponding to different downlink CQI (Channel Quality Indicator, Channel Quality Indicator) levels, and the i is determined according to the CQI level and the size of the data to be transmitted ; P _i is the distribution ratio of downlink users corresponding to the number of RBs i, and the P _i is determined according to cell MR (Measurement Report, measurement report) data;

The number of RBs available for the downlink Determined according to the following formula:

in, is the total number of downlink RBs, N _SIB is the number of RBs occupied by SIB (SystemInformation Block, system information block), is the number of downlink RBs occupied by RRC (Radio Resource Control, radio resource control) signaling, and N _Paging is the number of RBs occupied by paging.

Optionally, according to the number of available uplink RBs, the average number of uplink RBs occupied by each VoLTE service, and the second impact factor, determining the number of users U _PUSCH that can support the VoLTE service on the uplink physical shared channel PUSCH includes:

Determine the number of users U _PUSCH that the PUSCH can support VoLTE services according to the following formula:

in, is the number of RBs available for the uplink, For the average number of uplink RBs occupied by each VoLTE service, the second impact factor includes: retransmission factor F _Retrans , uplink time division duplex TDD factor Physical random access channel PRACH factor F _PRACH , voice activation factor VAF.

Optionally, the average number of uplink RBs occupied by each VoLTE service Determined according to the following formula:

Among them, N is the maximum number of uplink RBs that can be allocated in an LTE-TDD cell; j is the number of RBs corresponding to different uplink MCS (Modulation and Coding Scheme, modulation and coding strategy) levels _{, and} the j is determined according to the MCS level and the size of the data to be transmitted ; P _j is the distribution ratio of uplink users whose RB quantity is j, and the P _j is determined according to the MR data of the cell;

The number of RBs available for the uplink Determined according to the following formula:

in, is the total number of uplink RBs, The number of RBs occupied by the physical uplink control channel PUCCH, The number of uplink RBs occupied by RRC signaling.

Optionally, according to the number of resource units RE in each VoLTE service period, the average control channel unit CCE aggregation degree of the cell and the third impact factor, determine the number of users that the downlink physical control channel PDCCH can support for scheduling VoLTE uplink services _{UPDCCH_UL} and the number of users _{UPDCCH_DL} used to schedule VoLTE downlink services, including:

The number of resource unit REs in each VoLTE service cycle includes the number of REs that can be used by the PDCCH to schedule downlink services in each VoLTE service cycle and the number of REs that can be used by the PDCCH to schedule uplink services in each VoLTE service cycle;

Determine the number of users U _{PDCCH_DL} that the PDCCH can support for scheduling VoLTE downlink services according to the following formula:

Determine the number of users U _{PDCCH_UL} that the PDCCH can support for scheduling VoLTE uplink services according to the following formula:

Among them, R is the number of REs available for each CCE, The number of REs that the PDCCH can be used to schedule downlink services in each VoLTE service cycle, The number of REs that the PDCCH can be used to schedule uplink services in each VoLTE service cycle, is the average CCE aggregation degree of the cell; the third influencing factor includes: a retransmission factor F _Retrans , an SPS (Semi-Persistent Scheduling, semi-persistent scheduling) gain F _SPS , and a voice activation factor VAF.

Optionally, the number of REs that the PDCCH can be used to schedule downlink services in each VoLTE service cycle Determined according to the following formula:

Among them, k is the subframe sequence number in each VoLTE service cycle, P is the maximum number of subframes in each VoLTE service cycle, is the total number of REs in symbols occupied by PDCCHs that can be used to schedule downlink services, The number of REs occupied by the CRS (Cell Reference Signal, cell reference signal) channel in the symbol occupied by the PDCCH used to schedule the downlink service, The number of REs occupied by the PHICH (Physical Hybrid Automatic Repeat-Request Indicator Channel, Physical Hybrid Automatic Repeat-Request Indicator Channel) in the symbol occupied by the PDCCH used to schedule downlink services, The number of REs occupied by the PCFICH (Physical ControlFormat Indicator Channel, Physical Control Format Indicator Channel) in the symbol occupied by the PDCCH used to schedule downlink services;

The number of REs that PDCCH can be used to schedule uplink services in each VoLTE service cycle Determined according to the following formula:

in, is the total number of REs in symbols occupied by PDCCHs that can be used to schedule uplink services, is the number of REs occupied by the CRS channel in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PHICH in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PCFICH in symbols occupied by the PDCCH used to schedule uplink services;

The average CCE aggregation degree of the cell Determined according to the following formula:

Among them, x is the aggregation level, Q is the maximum aggregation level, is the user distribution ratio under different aggregation levels, the Determined from MR data.

Optionally, the determining the VoLTE service support capacity of the LTE-TDD cell according to the _UPDSCH , the _UPUSCH , the _{UPDCCH_UL} and the _{UPDCCH_DL} includes:

The minimum value among the _UPDSCH , the _UPUSCH , the _{UPDCCH_UL} and the _{UPDCCH_DL} is used as the VoLTE service support capacity of the LTE-TDD cell.

The embodiment of the present invention also provides a device for determining the service support capacity of an LTE-TDD cell, including:

PDSCH determination module: used to determine the number of users U _PDSCH that PDSCH can support VoLTE services according to the number of downlink available resource block RBs, the average number of downlink RBs occupied by each VoLTE service and the first impact factor;

PUSCH determination module: used to determine the number of users U _PUSCH that PUSCH can support VoLTE services according to the number of uplink available RBs, the average number of uplink RBs occupied by each VoLTE service and the second impact factor;

PDCCH determination module: used to determine the number of users that PDCCH can support for scheduling VoLTE uplink services according to the number of resource units RE in each VoLTE service cycle, the average control channel unit CCE aggregation degree of the cell, and the third impact factor U _{PDCCH_UL} and the number of users used for scheduling VoLTE uplink services The number of users U _{PDCCH_DL} for scheduling VoLTE downlink services;

The result determining module: used to determine the VoLTE service support capacity of the LTE-TDD cell according to the _UPDSCH , the _UPUSCH , the _{UPDCCH_UL} and the _{UPDCCH_DL} .

Optionally, the PDSCH determining module is also used for:

Determine the number of users U _PDSCH that the PDSCH can support VoLTE services according to the following formula:

in, is the number of RBs available for the downlink, is the average number of downlink RBs occupied by each VoLTE service, For the number of TTIs in each VoLTE service cycle, the first impact factor includes: retransmission factor F _Retrans , downlink time division duplex TDD factor Voice Activation Factor VAF.

Optionally, the PDSCH determining module is also used for:

Determine the average number of downlink RBs occupied by each VoLTE service according to the following formula

Among them, M is the maximum number of downlink RBs that can be allocated in an LTE-TDD cell; i is the number of RBs corresponding to different downlink channel quality indicator CQI levels, and the i is determined according to the CQI level and the size of the data to be transmitted; P _i is RB The quantity is the distribution ratio of downlink users corresponding to i, and the P _i is determined according to the MR data of the cell measurement report;

Determine the number of RBs available for the downlink according to the following formula

in, is the total number of downlink RBs, N _SIB is the number of RBs occupied by the system information block SIB, N Paging is the number of downlink RBs occupied by radio resource control RRC signaling, and N _Paging is the number of RBs occupied by paging.

Optionally, the PUSCH determining module is also used for:

Determine the number of users U _PUSCH that the PUSCH can support VoLTE services according to the following formula:

in, is the number of RBs available for the uplink, For the average number of uplink RBs occupied by each VoLTE service, the second impact factor includes: retransmission factor F _Retrans , uplink time division duplex TDD factor Physical random access channel PRACH factor F _PRACH , voice activation factor VAF.

Optionally, the PUSCH determining module is also used for:

Determine the average number of uplink RBs occupied by each VoLTE service according to the following formula

Among them, N is the maximum number of uplink RBs that can be allocated in an LTE-TDD cell; j is the number of RBs corresponding to different uplink modulation and coding strategies MCS levels _{, and} the j is determined according to the MCS level and the size of the data to be transmitted; P _j is the number of RBs is the uplink user distribution ratio of j, and the P _j is determined according to the cell measurement report MR data;

Determine the number of available uplink RBs according to the following formula

in, is the total number of uplink RBs, The number of RBs occupied by the physical uplink control channel PUCCH, The number of uplink RBs occupied by RRC signaling.

Optionally, the number of resource unit REs in each VoLTE service cycle includes the number of REs that can be used by the PDCCH to schedule downlink services in each VoLTE service cycle and the number of REs that can be used by the PDCCH to schedule uplink services in each VoLTE service cycle, The PDCCH determination module is also used for:

Determine the number of users U _{PDCCH_DL} that the PDCCH can support for scheduling VoLTE downlink services according to the following formula:

Determine the number of users U _{PDCCH_UL} that the PDCCH can support for scheduling VoLTE uplink services according to the following formula:

Among them, R is the number of REs available for each CCE, The number of REs that the PDCCH can be used to schedule downlink services in each VoLTE service cycle, The number of REs that the PDCCH can be used to schedule uplink services in each VoLTE service period, is the average CCE aggregation degree of the cell; the third influencing factor includes: a retransmission factor F _Retrans , a semi-persistent scheduling SPS gain F _SPS , and a voice activation factor VAF.

Optionally, the PDCCH determination module is also used for:

Determine the number of REs that PDCCH can use to schedule downlink services in each VoLTE service cycle according to the following formula

Among them, k is the subframe sequence number in each VoLTE service cycle, P is the maximum number of subframes in each VoLTE service cycle, is the total number of REs in symbols occupied by PDCCHs that can be used to schedule downlink services, is the number of REs occupied by the cell reference signal CRS channel in the symbol occupied by the PDCCH used to schedule downlink services, The number of REs occupied by the physical hybrid automatic repeat indicator channel PHICH in the symbol occupied by the PDCCH used to schedule downlink services, The number of REs occupied by the physical control format indicator channel PCFICH in symbols occupied by the PDCCH used to schedule downlink services;

Determine the number of REs that the PDCCH can use to schedule uplink services in each VoLTE service cycle according to the following formula

in, is the total number of REs in symbols occupied by PDCCHs that can be used to schedule uplink services, is the number of REs occupied by the CRS channel in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PHICH in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PCFICH in symbols occupied by the PDCCH used to schedule uplink services;

Determine the average CCE aggregation degree of the cell according to the following formula

Among them, x is the aggregation level, Q is the maximum aggregation level, is the user distribution ratio under different aggregation levels, the Determined from MR data.

Optionally, the result determination module is also used for:

The minimum value among the _UPDSCH , the _UPUSCH , the _{UPDCCH_UL} and the _{UPDCCH_DL} is used as the VoLTE service support capacity of the LTE-TDD cell.

The embodiment of the present invention provides a method and device for determining the service support capacity of an LTE-TDD cell. According to the number of available downlink RBs, the average number of downlink RBs occupied by each VoLTE service, and the first impact factor, it is determined that the PDSCH can support VoLTE services. number of users; according to the number of available uplink RBs, the average number of uplink RBs occupied by each VoLTE service, and the second impact factor, determine the number of users that PUSCH can support VoLTE services; according to the number of REs in each VoLTE service cycle, the average number of The CCE aggregation degree and the third impact factor determine the number of users that the PDCCH can support for scheduling VoLTE uplink services and the number of users for scheduling VoLTE downlink services; finally determine the VoLTE service support capacity of the LTE-TDD cell. The method and device for determining the service support capacity of an LTE-TDD cell provided by the embodiments of the present invention are of great significance for overall network planning and service development strategies.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a schematic flow chart of a method for determining the VoLTE service support capacity of an LTE-TDD cell provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of a method for determining the distribution ratio of downlink users provided by an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an apparatus for determining the VoLTE service support capacity of an LTE-TDD cell provided by an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments . Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The VoLTE service belongs to the packet domain service, and its capacity directly depends on the spectrum efficiency. As shown in Table 1, due to the mutual constraints and influences of different service quality requirements, wireless resources, network configuration, wireless environment, and feature functions, the LTE The system's support capacity for VoLTE services is not a fixed value, and due to the particularity of the LTE-TDD network in the time domain, it is necessary to form a model for estimating the VoLTE service capacity by constraining various influencing conditions.

For different physical channels, there are differences in their network configuration, resource allocation method, resource occupation quantity, and so on. According to Table 1, it can be seen that PDSCH capacity, PUSCH capacity, and PUSCH capacity jointly affect the supportable capacity of VoLTE services. Therefore, it is necessary to calculate the supportable capacity of each physical channel separately, and finally determine the LTE service based on the supportable capacity of each physical channel. -TDD cells support capacity for VoLTE services.

Table 1 Factors Affecting VoLTE Supportable Capacity

Fig. 1 exemplarily shows a schematic flow chart of a method for determining the VoLTE service support capacity of an LTE-TDD cell provided by an embodiment of the present invention, including:

Step 101: According to the number of available downlink RBs, the average number of downlink RBs occupied by each VoLTE service and the first impact factor, determine the number of users U _PDSCH that the PDSCH can support the VoLTE service.

Specifically, the number of users U _PDSCH that PDSCH can support VoLTE services is determined according to formula (1):

in, is the number of RBs available for downlink, is the average number of downlink RBs occupied by each VoLTE service, It is the number of transmission time interval TTIs in each VoLTE service cycle. The first impact factors include: retransmission factor F _Retrans , downlink TDD factor Voice Activation Factor VAF.

For the average number of downlink RBs occupied by each VoLTE service in formula (1) It can be determined according to formula (2):

Among them, M is the maximum number of downlink RBs that can be allocated to an LTE-TDD cell. Since the number of downlink RBs available in the LTE system with a maximum bandwidth of 20M is 100, the value of M is 100.

i is the number of RBs corresponding to different downlink channel quality indicator CQI levels, i is determined according to the CQI level and the size of the data to be transmitted; P _i is the distribution ratio of downlink users corresponding to the number of RBs i, and P _i reports MR data according to the cell measurement Sure.

For the number of RBs available for downlink in formula (1) Determined according to formula (3):

in, is the total number of downlink RBs, N _SIB is the number of RBs occupied by the system information block SIB, N Paging is the number of downlink RBs occupied by radio resource control RRC signaling, and N _Paging is the number of RBs occupied by paging.

Step 102: According to the number of available uplink RBs, the average number of uplink RBs occupied by each VoLTE service and the second impact factor, determine the number of users U PUSCH that can support the VoLTE service on the uplink physical shared channel _PUSCH .

Specifically, the number of users U _PUSCH that PUSCH can support VoLTE services is determined according to formula (4):

in, is the number of RBs available for uplink, is the average number of uplink RBs occupied by each VoLTE service. The second impact factor includes: retransmission factor F _Retrans , uplink TDD factor PRACH factor F _PRACH , voice activation factor VAF.

For the average number of uplink RBs occupied by each VoLTE service in formula (4) According to formula (5), it is determined that:

Among them, N is the maximum number of uplink RBs that can be allocated in an LTE-TDD cell. Since the number of uplink RBs available in the LTE system with a maximum bandwidth of 20M is 100, the value of N is 100.

j is the number of RBs corresponding to different uplink MCS levels _{, and} j is determined according to the MCS level and the size of the data to be transmitted; P _j is the distribution ratio of uplink users whose number of RBs is j, and P _j is determined according to the MR data of the cell.

The number of RBs available for the uplink in formula (4) It can be determined according to formula (6):

in, is the total number of uplink RBs, The number of RBs occupied by the physical uplink control channel PUCCH, The number of uplink RBs occupied by RRC signaling.

Step 103: According to the number of resource units RE in each VoLTE service cycle, the average cell: CCE aggregation degree and the third impact factor, determine the number of users that the downlink physical control channel PDCCH can support for scheduling VoLTE uplink services U _{PDCCH_UL} and the number of users for scheduling VoLTE uplink services The number of users U _{PDCCH_DL} for scheduling VoLTE downlink services.

The number of resource unit REs in each VoLTE service cycle includes the number of REs that can be used by the PDCCH to schedule downlink services in each VoLTE service cycle and the number of REs that can be used by the PDCCH to schedule uplink services in each VoLTE service cycle.

Specifically, determine the number of users U _{PDCCH_DL} that the PDCCH can support for scheduling VoLTE downlink services according to formula (7):

Determine the number of users U _{PDCCH_UL} that the PDCCH can support for scheduling VoLTE uplink services according to formula (8):

Among them, R is the number of REs available for each CCE. Since 1 CCE is equivalent to 9 REGs (Resource Element Group, RE set), and 1 REG is equivalent to 4 available REs, one CCE is equivalent to 36 REs, so R The value is 36.

The number of REs that PDCCH can be used to schedule downlink services in each VoLTE service cycle, The number of REs that the PDCCH can be used to schedule uplink services in each VoLTE service cycle, is the average CCE aggregation degree of the cell; the third influencing factor includes: retransmission factor F _Retrans , SPS gain F _SPS , and voice activation factor VAF.

For each VoLTE service cycle in formula (7), the number of REs that PDCCH can be used to schedule downlink services It can be determined according to formula (9):

Among them, k is the subframe sequence number in each VoLTE service cycle, and P is the maximum number of subframes in each VoLTE service cycle. Since the maximum number of subframes in each VoLTE service cycle is 20, the value of P is 20 .

is the total number of REs in symbols occupied by PDCCHs that can be used to schedule downlink services, is the number of REs occupied by the CRS channel in the symbol occupied by the PDCCH used to schedule downlink services, is the number of REs occupied by the PHICH in the symbol occupied by the PDCCH used to schedule downlink services, is the number of REs occupied by the PCFICH in the symbol occupied by the PDCCH used to schedule downlink services;

For each VoLTE service cycle in formula (8), the number of REs that PDCCH can be used to schedule uplink services It can be determined according to formula (10):

in, is the total number of REs in symbols occupied by PDCCHs that can be used to schedule uplink services, is the number of REs occupied by the CRS channel in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PHICH in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PCFICH in the symbol occupied by the PDCCH used to schedule uplink services;

For the average CCE aggregation degree of the cell It can be determined according to formula (11):

Among them, x is the aggregation level, and Q is the maximum aggregation level. Since the PDCCH CCE has four types of aggregation levels, the value of Q is 4; is the user distribution ratio under different aggregation levels, Determined from MR data.

It should be noted that the order of step 101, step 102, and step 103 in the embodiment of the present invention can be changed arbitrarily, and no specific limitation is set here.

Step 104: According to _UPDSCH , _UPUSCH , _{UPDCCH_UL} and _{UPDCCH_DL} , determine the VoLTE service support capacity of the LTE-TDD cell.

Specifically, according to the _UPDSCH , _UPUSCH , _{UPDCCH_UL} and _{UPDCCH_DL} determined by the above method, the minimum value is obtained by comparison, and the minimum value is used as the VoLTE service support capacity of the LTE-TDD cell.

The embodiment of the present invention is based on the channel resource allocation method, and the basis for determining the support capacity of the LTE-TDD cell for the VoLTE service is the characteristics of the physical layer of the LTE air interface, which has the characteristics of active planning, strong pertinence, and high accuracy. Based on the calculation of each physical channel resource, the embodiment of the present invention combines the analysis of the user model, has stronger flexibility and adaptability to the existing network, and forms a complete estimation method for the VoLTE service support capability under the LTE-TDD network.

When deploying VoLTE services on an LTE-TDD network, the communication operator can estimate how many VoLTE users can be supported by the existing network resources based on the calculation method provided by the embodiment of the present invention, so as to further formulate network expansion based on business development goals solutions and VoLTE user development strategies.

The embodiment of the present invention provides a method and device for determining the service support capacity of an LTE-TDD cell. According to the number of available downlink RBs, the average number of downlink RBs occupied by each VoLTE service, and the first impact factor, it is determined that the PDSCH can support VoLTE services. number of users; according to the number of available uplink RBs, the average number of uplink RBs occupied by each VoLTE service, and the second impact factor, determine the number of users that PUSCH can support VoLTE services; according to the number of REs in each VoLTE service cycle, the average number of The CCE aggregation degree and the third impact factor determine the number of users that the PDCCH can support for scheduling VoLTE uplink services and the number of users for scheduling VoLTE downlink services; finally determine the VoLTE service support capacity of the LTE-TDD cell. The method and device for determining the service support capacity of an LTE-TDD cell provided by the embodiments of the present invention are of great significance for overall network planning and service development strategies.

The method for determining the number of users that the PDSCH can support the VoLTE service will be described in detail below.

For the number of TTIs in each VoLTE service cycle in formula (1) Generally, for a VoLTE voice frame, 20 ms of voice packets can be packed into one TTI for carrying, so voice packets of 20 users can be scheduled within 20 ms, that is, the number of TTIs in each VoLTE service cycle is 20.

For the retransmission factor F _Retrans in formula (1), the system will have different retransmission rates according to different wireless environments, and generally 10% is used as the convergence target.

For the downlink TDD factor in formula (1) Determined by the TDD frame structure, there are 10 subframes in each frame, and each subframe has 14 OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) symbols. For the downlink channel, the TDD factor can be determined according to formula (12):

The ratio of the above downlink subframes is 2, the ratio of special subframes is 7, the number of downlink subframes is 6, and the number of symbols available for special subframes is 20. For example, the downlink TDD factor If it is further considered that the number of downlink subframes 3 and 8 are only used for uplink VoLTE scheduling on the PDCCH, the effective downlink TDD factor

For the voice activation factor VAF in formula (1), since voice calls have silent periods and active periods, and the data rate transmitted during the silent period is much lower than the active period, the voice activation factor VAF can be obtained through data collection statistics or simulation.

For the number of RBs available for downlink in formula (1) Mainly depends on the total number of downlink RBs and It can be determined by the frequency bandwidth, for example, there are 100 RBs in a 20MHz bandwidth. In order to accurately obtain the resources available for service data transmission and determine the total number of downlink RBs, necessary SIB, Paging (paging), RRC signaling and other overheads need to be eliminated. For different bandwidths, the total number of downlink RBs is as described in Table 2:

Table 2 The total number of downlink RBs corresponding to different bandwidths

Bandwidth (MHz) 1.4 3 5 10 15 20 Total number of downlink RBs 6 15 25 50 75 100

It should be noted that since the service period of VoLTE voice packets is 20ms, when calculating the RB resources occupied by SIB messages, RRC signaling and Paging messages, the calculation in the time domain takes 20ms as the statistical period.

For the number of RBs N _SIB occupied by the SIB in formula (3), it represents the number of RB resources used to transmit SIB system messages in the PDSCH, which can be obtained based on the number of RBs required by the SIB. The number of RB resources occupied by different SIB messages is different. Taking frame configuration 2 as an example, the quantity and period of resources occupied by the main SIB messages in the connected state are shown in Table 3:

Table 3 Number of RBs occupied by SIBs

For the number of downlink RBs occupied by RRC signaling in formula (3) Represents the number of RB resources used to transmit RRC signaling in PDSCH. RRC signaling mainly includes signaling such as call establishment and handover, and the model can be acquired through live network test collection. Taking the voice channel coding rate as Z kbps as an example, if the average size of the RRC signaling used for each handover is about X Byte, and the number of handovers per minute is W, the average size of the signaling used for each VoLTE call establishment is about Y Byte, the RRC signaling overhead is estimated based on the business model of one call establishment, then the number of downlink RBs occupied by RRC signaling can be determined according to formula (13):

Among them, the numerator is the RRC signaling consumed by each call establishment and switching during a one-minute call, and the numerator Z*60/0.02 is the amount of data that can be transmitted by a VoLTE voice packet within one minute, and the unit is bit (bit). Consistent with the molecular unit Byte (byte), it needs to be divided by 8 to obtain the number of downlink RBs occupied by the RRC signaling overhead.

The number of resources occupied by paging in formula (3) depends on the PCCH channel configuration and the actual paging load of the network, and can be obtained by collecting statistical data of the live network.

For the average number of downlink RBs occupied by each VoLTE call in formula (1) Depending on the wireless environment where the user is located, the number _i of RBs corresponding to different downlink CQI levels is multiplied by the distribution ratio _Pi . Net MR acquisition is OK.

In the embodiment of the present invention, the number of RBs occupied by each VoLTE call is different due to different wireless environments. In the downlink direction, the network obtains the wireless quality of the downlink through the CQI reported by the terminal. After obtaining the amount of data to be transmitted and the CQI, according to the 3GPP (3rd Generation Partnership Project, 3rd Generation Partnership Project) specification, through table lookup How many RBs need to be allocated by the network for service use to obtain different wireless environments corresponding to different CQI levels.

For the downlink user distribution ratio P _i , it can be determined in the following two ways:

Based on MR data acquisition method: according to the terminal test data, obtain the SINR (Signal to Interference plus Noise Ratio, signal to interference plus noise ratio), RSRP (Reference Signal Receiving Power, reference signal received power), CQI data in the sampling point, and simulate A combined method (such as the linear least square method) is used to form the corresponding relationship between RSRP and CQI or SINR and CQI. Then collect the MR data of the cells in the whole network, calculate the distribution ratio of RSRP or SINR in the MR sampling points, and obtain the corresponding CQI user distribution ratio according to the distribution ratio of RSRP or SINR.

Mathematical model method: Taking the concentric circle model as an example, Figure 2 is a schematic diagram of a method for determining the distribution ratio of downlink users provided by the embodiment of the present invention, and assigning different RB resource allocations to the set wireless quality level, such as There are four types of wireless quality levels: excellent, good, mid-point, and almost. In these four types of coverage scenarios, the distances of users in the coverage radial direction are the same, which are d, 2d, 3d, and 4d respectively. The coverage area of the excellent point is πd ² , the coverage area of the good point is π(2d) ² -πd ² , the coverage area of the midpoint is π(3d) ² -π(2d) ² , and the coverage area of the near point is π(4d) ² -π(3d) ² , that is, the user The distribution model is excellent point: good point: middle point: almost point = 1:3:5:7; thus the corresponding distribution ratio of downlink users in various scenarios can be obtained.

According to the above specific calculation and analysis method, the number of users U _PDSCH that the PDSCH can support the VoLTE service can be determined.

The method for determining the number of users that the PUSCH can support the VoLTE service will be described in detail below.

For the number of TTIs in each VoLTE service cycle in formula (4) Generally, for a VoLTE voice frame, 20 ms of voice packets can be packed into one TTI for carrying, so voice packets of 20 users can be scheduled within 20 ms, that is, the number of TTIs in each VoLTE service cycle is 20.

For the retransmission factor F _Retrans in formula (4), the system will have different retransmission rates according to different wireless environments, and generally 10% is used as the convergence target.

For the uplink TDD factor in formula (4) It can be determined according to formula (14):

For different subframe configurations, the uplink TDD factor There are different values. If the subframe ratio is 2 and the special subframe configuration is 7, then the TDD factor

For the voice activation factor VAF in formula (4), since voice calls have silent periods and active periods, and the data rate transmitted during the silent period is much lower than the active period, the voice activation factor VAF can be obtained through data collection statistics or simulation.

For the PRACH factor F _PRACH in formula (4), the uplink resource needs to reserve a PRACH channel in a specific frequency domain and time domain for sending random access preambles. The length in the time domain varies according to different PRACH formats, but the PRACH channel always occupies 6 RBs in the frequency domain. The PRACH configuration indicator shows the number of PRACH transmissions within 10ms. For the subframe configuration with the uplink and downlink subframe ratio of 2 and the special subframe ratio of 7, check the table through the 3GPP specification. If PRACH has X transmission opportunities within 10ms , then F _PRACH =1-(6*X/90×2).

Number of RBs available for uplink Mainly depends on the total number of uplink RBs and It can be determined by the frequency bandwidth, for example, there are 100 RBs in a 20MHz bandwidth. In order to obtain the resources available for service data transmission accurately, the number of RBs occupied by the necessary PUCCH and the number of uplink RBs occupied by RRC signaling need to be eliminated to determine the total number of uplink RBs. For different bandwidths, the number of uplink RBs is as described in Table 4:

Table 4 The total number of uplink RBs corresponding to different bandwidths

Bandwidth (MHz) 1.4 3 5 10 15 20 Total number of uplink RBs 6 15 25 50 75 100

For the number of RBs occupied by the uplink PUCCH in formula (6) It can be determined through parameter configuration. The number of RB resources used to transmit RRC signaling in the PUSCH in formula (6) can be obtained in the same way as formula (13).

For the average number of uplink RBs occupied by each VoLTE service in formula (1) Since the number of uplink RBs depends on the scheduling strategy of the system, after determining the MCS and the amount of data to be transmitted, look up the table according to the 3GPP specification to obtain how many PRBs need to be allocated by the network for service use for different uplink MCSs corresponding to different wireless environments. Based on the RB resources required by the above different uplink MCSs, the corresponding uplink user distribution ratios can be selected respectively, and the average number of uplink RBs occupied by each VoLTE service can be obtained by multiplying the two levels and summing them. For the user distribution P _j in the formula (5), it can be obtained by selecting a mathematical model and based on the statistics of the uplink MCS level according to the degree of refinement of the required results.

According to the above specific calculation and analysis method, the number U _PUSCH of users that the PUSCH can support the VoLTE service can be determined.

The method for determining the number of users that the PDCCH can support for scheduling the VoLTE uplink service and the number of users for scheduling the VoLTE downlink service will be described in detail below.

PDCCH is used to carry the transmission of downlink control information, including downlink scheduling allocation and uplink scheduling authorization, uplink power control command, paging message scheduling authorization, RACH (Random Access Channel, random access channel) response scheduling authorization and other signaling, through DCI (Downlink Control Information, downlink control information block) bearer, different users use different DCI resources. It can occupy the full bandwidth in the frequency domain, and occupy the first n OFDM symbols of each downlink subframe in the frequency domain, where n<=3.

The allocation method of the PDCCH is different from that of the PDSCH and the PUSCH, and the PDCCH is allocated based on a CCE unit. Since 1 CCE is equivalent to 9 REGs, and 1 REG is equivalent to 4 available REs, one CCE is equivalent to 36 REs.

For the retransmission factor F _Retrans in formula (7) and formula (8), the system will have different retransmission rates according to different wireless environments, and generally 10% is used as the convergence target.

For the voice activation factor VAF in formula (7) and formula (8), since there are silent periods and active periods in voice calls, and the data rate transmitted during the silent period is much lower than the active period, the voice can be obtained through data collection statistics or simulation Activation factor VAF.

For the SPS gain F _SPS in formula (7) and formula (8), the gain obtained on the PDCCH resource after using the semi-persistent scheduling technology is mainly considered. In order to reduce the overhead of PDCCH resources for services that are relatively stable in VoLTE resource scheduling, the semi-persistent scheduling (SPS) function can be enabled, that is, the resources are scheduled to users for a longer time, thereby increasing the maximum number of users that can be scheduled simultaneously on the PDCCH channel. The SPS gain can be determined by the ratio of the PDCCH dynamic scheduling times to the semi-persistent scheduling times within a certain talk time.

In addition, since PDCCH is used to allocate uplink and downlink resources, PDCCH needs to be consumed, so the number of CCEs on the PDCCH used to schedule downlink resources and the number of CCEs on the PDCCH used to schedule uplink resources need to be calculated separately. It is obtained by subtracting the number of REs occupied by the CRS channel, PHICH channel, and PCFICH channel from the number of REs.

For the formula (9) in and in formula (10) It can be determined according to the network configuration. Taking CFI (Control Format Indicator, control format indication) equal to 3 as an example, that is, there are 3 OFDM symbols used for PDCCH, then the total number of REs used for PDCCH=1200×3=3600REs. Taking subframe ratio 2 as an example, when the demand for uplink scheduling of the cell is large, that is, the PDCCH of subframe 3 and subframe 8 are completely used for uplink scheduling, then the number of PDCCH CCEs available in each subframe is shown in Table 5:

Table 5 Number of CCEs in each subframe of PDCCH under subframe configuration 2

In addition, PDCCH CCE has four types of aggregation levels, namely 1, 2, 4, and 8 levels. For different wireless environments, different aggregation levels are used for data transmission to improve reliability. The four aggregation levels of CCE correspond to different levels of wireless quality. For the distribution ratio of users under different aggregation levels in formula (11) The corresponding user distribution ratio can be obtained according to the MR data by collecting the CCE aggregation distribution of the PDCCH on the live network

According to the above specific calculation and analysis method, the method for determining the number of users that the PDCCH can support for scheduling the VoLTE uplink service and the number of users for scheduling the VoLTE downlink service can be determined.

It should be noted that the number of users that PDSCH can support VoLTE service, the number of users that PUSCH can support VoLTE service, the number of users that PDCCH can support for scheduling VoLTE uplink services and the number of users for scheduling VoLTE downlink services determined by the above specific calculation and analysis method The number of users of the service, and finally comprehensively determine the support capacity of the LTE-TDD cell for the VoLTE service. Specifically, the minimum value may be used as the VoLTE service support capacity of the LTE-TDD cell, or the VoLTE service support capacity of the LTE-TDD cell may be determined through curve fitting, and there is no limitation here.

Based on the same inventive concept, the embodiment of the present invention also provides a device for determining the service support capacity of the LTE-TDD cell, as shown in FIG. Structure diagram, including:

PDSCH determination module 301: used to determine the number of users U _PDSCH that PDSCH can support VoLTE services according to the number of downlink available resource block RBs, the average number of downlink RBs occupied by each VoLTE service and the first impact factor;

PUSCH determination module 302: used to determine the number of users U _PUSCH that PUSCH can support VoLTE services according to the number of uplink available RBs, the average number of uplink RBs occupied by each VoLTE service and the second impact factor;

PDCCH determination module 303: used to determine the number of users that PDCCH can support for scheduling VoLTE uplink services U _{PDCCH_UL} and The number of users U _{PDCCH_DL} used to schedule VoLTE downlink services;

The result determining module 304: used to determine the VoLTE service support capacity of the LTE-TDD cell according to the _UPDSCH , the _UPUSCH , the _{UPDCCH_UL} and the _{UPDCCH_DL} .

Optionally, the PDSCH determining module 301 is also used for:

Determine the number of users U _PDSCH that the PDSCH can support VoLTE services according to the following formula:

in, is the number of RBs available for the downlink, is the average number of downlink RBs occupied by each VoLTE service, For the number of TTIs in each VoLTE service cycle, the first impact factor includes: retransmission factor F _Retrans , downlink time division duplex TDD factor Voice Activation Factor VAF.

Optionally, the PDSCH determining module 301 is also used for:

Determine the average number of downlink RBs occupied by each VoLTE service according to the following formula

Among them, M is the maximum number of downlink RBs that can be allocated in an LTE-TDD cell; i is the number of RBs corresponding to different downlink channel quality indicator CQI levels, and the i is determined according to the CQI level and the size of the data to be transmitted; P _i is RB The quantity is the distribution ratio of downlink users corresponding to i, and the P _i is determined according to the MR data of the cell measurement report;

Determine the number of RBs available for the downlink according to the following formula

in, is the total number of downlink RBs, N _SIB is the number of RBs occupied by the system information block SIB, N Paging is the number of downlink RBs occupied by radio resource control RRC signaling, and N _Paging is the number of RBs occupied by paging.

Optionally, the PUSCH determining module 302 is also used for:

Determine the number of users U _PUSCH that the PUSCH can support VoLTE services according to the following formula:

in, is the number of RBs available for the uplink, For the average number of uplink RBs occupied by each VoLTE service, the second impact factor includes: retransmission factor F _Retrans , uplink time division duplex TDD factor Physical random access channel PRACH factor F _PRACH , voice activation factor VAF.

Optionally, the PUSCH determining module 302 is also used for:

Determine the average number of uplink RBs occupied by each VoLTE service according to the following formula

Among them, N is the maximum number of uplink RBs that can be allocated in an LTE-TDD cell; j is the number of RBs corresponding to different uplink modulation and coding strategies MCS levels _{, and} the j is determined according to the MCS level and the size of the data to be transmitted; P _j is the number of RBs is the uplink user distribution ratio of j, and the P _j is determined according to the cell measurement report MR data;

Determine the number of available uplink RBs according to the following formula

in, is the total number of uplink RBs, The number of RBs occupied by the physical uplink control channel PUCCH, The number of uplink RBs occupied by RRC signaling.

Optionally, the number of resource unit REs in each VoLTE service cycle includes the number of REs that can be used by the PDCCH to schedule downlink services in each VoLTE service cycle and the number of REs that can be used by the PDCCH to schedule uplink services in each VoLTE service cycle, The PDCCH determining module 303 is also used for:

Determine the number of users U _{PDCCH_DL} that the PDCCH can support for scheduling VoLTE downlink services according to the following formula:

Determine the number of users U _{PDCCH_UL} that the PDCCH can support for scheduling VoLTE uplink services according to the following formula:

Among them, R is the number of REs available for each CCE, The number of REs that the PDCCH can be used to schedule downlink services in each VoLTE service cycle, The number of REs that the PDCCH can be used to schedule uplink services in each VoLTE service cycle, is the average CCE aggregation degree of the cell; the third influencing factor includes: a retransmission factor F _Retrans , a semi-persistent scheduling SPS gain F _SPS , and a voice activation factor VAF.

Optionally, the PDCCH determination module 303 is also used for:

Determine the number of REs that PDCCH can use to schedule downlink services in each VoLTE service cycle according to the following formula

Among them, k is the subframe sequence number in each VoLTE service cycle, P is the maximum number of subframes in each VoLTE service cycle, is the total number of REs in symbols occupied by PDCCHs that can be used to schedule downlink services, is the number of REs occupied by the cell reference signal CRS channel in the symbol occupied by the PDCCH used to schedule downlink services, The number of REs occupied by the physical hybrid automatic repeat indicator channel PHICH in the symbol occupied by the PDCCH used to schedule downlink services, The number of REs occupied by the physical control format indicator channel PCFICH in symbols occupied by the PDCCH used to schedule downlink services;

Determine the number of REs that the PDCCH can use to schedule uplink services in each VoLTE service cycle according to the following formula

in, is the total number of REs in symbols occupied by PDCCHs that can be used to schedule uplink services, is the number of REs occupied by the CRS channel in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PHICH in the symbol occupied by the PDCCH used to schedule uplink services, is the number of REs occupied by the PCFICH in symbols occupied by the PDCCH used to schedule uplink services;

Determine the average CCE aggregation degree of the cell according to the following formula

Among them, x is the aggregation level, Q is the maximum aggregation level, is the user distribution ratio under different aggregation levels, the Determined from MR data.

Optionally, the result determination module 304 is further configured to:

The minimum value among the _UPDSCH , the _UPUSCH , the _{UPDCCH_UL} and the _{UPDCCH_DL} is used as the VoLTE service support capacity of the LTE-TDD cell.

The embodiment of the present invention is based on the channel resource allocation method, and the basis for determining the support capacity of the LTE-TDD cell for the VoLTE service is the characteristics of the physical layer of the LTE air interface, which has the characteristics of active planning, strong pertinence, and high accuracy. Based on the calculation of each physical channel resource, the embodiment of the present invention combines the analysis of the user model, has stronger flexibility and adaptability to the existing network, and forms a complete estimation method for the VoLTE service support capability under the LTE-TDD network.

When deploying VoLTE services on an LTE-TDD network, the communication operator can estimate how many VoLTE users can be supported by the existing network resources based on the calculation method provided by the embodiment of the present invention, so as to further formulate network expansion based on business development goals solutions and VoLTE user development strategies.

The embodiment of the present invention provides a device for determining the service support capacity of an LTE-TDD cell, and determines the users whose PDSCH can support the VoLTE service according to the number of available downlink RBs, the average number of downlink RBs occupied by each VoLTE service, and the first impact factor number; according to the number of available uplink RBs, the average number of uplink RBs occupied by each VoLTE service, and the second impact factor, determine the number of users that PUSCH can support VoLTE services; according to the number of REs in each VoLTE service cycle, the average CCE aggregation Degree and the third impact factor, determine the number of users that PDCCH can support for scheduling VoLTE uplink services and the number of users for scheduling VoLTE downlink services; finally determine the support capacity of the LTE-TDD cell for VoLTE services. The determination of LTE-TDD cell service support capacity and device provided by the embodiment of the present invention is of great significance for overall network planning and service development strategy.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a A system for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising a system of instructions, the The system implements the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (16)

1. A method for determining long term evolution LTE-TDD cell service support capacity based on time division duplex is characterized by comprising the following steps:

determining the number U of users of a downlink physical shared channel (PDSCH) capable of supporting the VoLTE service according to the number of downlink available Resource Blocks (RBs), the number of downlink RBs occupied by each voice solution VoLTE service and a first influence factor_PDSCH；

Determining an uplink physical shared channel according to the number of RBs available for uplink, the number of uplink RBs occupied by each VoLTE service on average and a second influence factorUser number U of PUSCH (physical uplink shared channel) capable of supporting VoLTE (voice over long term evolution) service_PUSCH；

Determining the number U of users for scheduling VoLTE uplink service which can be supported by a PDCCH (physical Downlink control channel) according to the number of Resource Elements (REs) in each VoLTE service period, the polymerization degree of CCE (control channel element average) in a cell and a third influence factor_{PDCCH_UL}And user number U for scheduling VoLTE downlink service_{PDCCH_DL}；

According to the U_PDSCHThe U_PUSCHThe U_{PDCCH_UL}And the U_{PDCCH_DL}And determining the support capacity of the LTE-TDD cell to the VoLTE service.

2. The method of claim 1, wherein the determining the number U of users of the downlink physical shared channel PDSCH capable of supporting the VoLTE service is based on the number of downlink available resource blocks RB, the number of downlink RBs occupied by each VoLTE service on average, and the first impact factor_PDSCHThe method comprises the following steps:

determining the number U of users of the PDSCH capable of supporting VoLTE service according to the following formula_PDSCH：

$U_{PDSCH}=\frac{N_{RB}^{DL}\&times;{\mathrm{NB}}_{TTI}^{VoLTE}\&times;(1-F_{\mathrm{Re}trans})\&times;F_{TDD}^{DL}}{\stackrel{\&OverBar;}{N_{DL\_RB}^{VoLTE}}\&times;VAF}$

Wherein,for the number of RBs available for the downlink,for the average number of downlink RBs occupied per VoLTE service,for the number of transmission time intervals, TTIs, in each VoLTE service period, the first impact factor includes: retransmission factor F_RetransDownlink time division duplex TDD factorVoice activationFactor VAF.

3. The method of claim 2, wherein the average number of downlink RBs occupied per VoLTE serviceDetermined according to the following formula:

$\stackrel{\&OverBar;}{N_{DL\_RB}^{VoLTE}}=\underset{i=1}{\overset{M}{\&Sigma;}}(i\&times;P_i)$

wherein, M is the maximum allocable downlink RB quantity of the LTE-TDD cell; i is the number of RBs corresponding to different downlink channel quality indicator CQI grades, and the i is determined according to the CQI grades and the size of data to be transmitted; p_iFor the distribution proportion of downlink users corresponding to the RB number i, the P_iDetermining according to the MR data of the cell measurement report;

the number of RBs available for downlinkDetermined according to the following formula:

$N_{RB}^{DL}=(N_{RB\_ALL}^{DL}-N_{SIB}-N_{RRC}^{PDSCH}-N_{Paging})$

wherein,for the total number of RBs in downlink, N_SIBThe number of RBs occupied by the system information block SIB,Number of downlink RBs, N occupied for radio resource control RRC signalling_PagingThe number of RBs occupied for paging.

4. The method of claim 1, wherein the determination of the number U of users of the uplink physical shared channel PUSCH capable of supporting VoLTE service is performed according to the number of RBs available in uplink, the number of RBs occupied by each VoLTE service in uplink on average, and the second impact factor_PUSCHThe method comprises the following steps:

determining the number U of users of the PUSCH capable of supporting VoLTE service according to the following formula_PUSCH：

$U_{PUSCH}=\frac{N_{RB}^{DL}\&times;{\mathrm{NB}}_{TTI}^{VoLTE}\&times;(1-F_{\mathrm{Re}trans})\&times;F_{TDD}^{DL}\&times;F_{PRACH}}{\stackrel{\&OverBar;}{N_{DL\_RB}^{VoLTE}}\&times;VAF}$

Wherein,the number of RBs available for the uplink is,for the average number of uplink RBs occupied by each VoLTE service, the second impact factor includes: retransmission factor F_RetransUplink time division duplex TDD factorPhysical random access channel PRACH factor F_PRACHVoice activation factor VAF.

5. The method of claim 4, wherein the average number of uplink RBs occupied per VoLTE serviceDetermined according to the following formula:

$\stackrel{\&OverBar;}{N_{UL\_RB}^{VoLTE}}=\underset{j=1}{\overset{N}{\&Sigma;}}(j\&times;P_j)$

wherein, N is the maximum allocable uplink RB quantity of the LTE-TDD cell; j is the number of RBs corresponding to different modulation coding strategy MCS levels of the uplink_，The j is determined according to the MCS level and the size of the data to be transmitted; p_jFor the distribution proportion of the uplink users with the RB number j, the P_jDetermining according to the cell MR data;

the number of RBs available for uplinkDetermined according to the following formula:

$N_{RB}^{UL}=(N_{RB\_ALL}^{UL}-N_{RB}^{PUCCH}-N_{RRC}^{PUSCH})$

wherein,for the total number of uplink RBs,The number of RBs occupied by the physical uplink control channel PUCCH,The number of uplink RBs occupied for RRC signaling.

6. The method of claim 1, wherein the determination of the number of users U that the PDCCH can support for scheduling the VoLTE uplink service is made according to the number of resource elements RE in each VoLTE service period, the cell average control channel element CCE aggregation level, and a third impact factor_{PDCCH_UL}And user number U for scheduling VoLTE downlink service_{PDCCH_DL}The method comprises the following steps:

the resource unit RE number in each VoLTE service period comprises the RE number which can be used by the PDCCH for scheduling downlink service in each VoLTE service period and the RE number which can be used by the PDCCH for scheduling uplink service in each VoLTE service period;

determining the number U of users which can be supported by the PDCCH for scheduling VoLTE downlink service according to the following formula_{PDCCH_DL}：

$U_{PDCCH\_DL}=\frac{ROUNDUP(\stackrel{\&OverBar;}{N_{RE\_DL}^{CONTROL}}/R)\&times;(1-F_{\mathrm{Re}trans})\&times;F_{SPS}}{\stackrel{\&OverBar;}{P^{CCE}}\&times;VAF}$

Determining the number U of users which can be supported by the PDCCH for scheduling VoLTE uplink service according to the following formula_{PDCCH_UL}：

$U_{PDCCH\_UL}=\frac{ROUNDUP(\stackrel{\&OverBar;}{N_{RE\_UL}^{CONTROL}}/R)\&times;(1-F_{\mathrm{Re}trans})\&times;F_{SPS}}{\stackrel{\&OverBar;}{P^{CCE}}\&times;VAF}$

Where R is the number of REs available per CCE,for the number of REs that can be used for scheduling downlink services in the PDCCH in each VoLTE service period,For the number of REs available for the PDCCH to schedule uplink traffic in each VoLTE traffic period,is the cell average CCE aggregation level; the third influencing factor comprises: retransmission factor F_RetransSemi-persistent scheduling (SPS) gain F_SPSVoice activation factor VAF.

7. The method of claim 6, wherein the number of REs available to the PDCCH for scheduling downlink traffic in each VoLTE traffic periodDetermined according to the following formula:

$\stackrel{\&OverBar;}{N_{RE\_DL}^{CONTROL}}=\underset{k=1}{\overset{P}{\&Sigma;}}(N_{kRE\_DL}^{CONTROL}-N_{kRE\_DL}^{CRS}-N_{kRE\_DL}^{PHICH}-N_{kRE\_DL}^{PCFICH})$

wherein k is the subframe number in each VoLTE service period, P is the maximum subframe number in each VoLTE service period,the total number of REs in a symbol occupied for PDCCH available for scheduling downlink traffic,the number of REs occupied by a Cell Reference Signal (CRS) channel in a symbol occupied by a PDCCH for scheduling downlink traffic,The number of REs occupied by a physical hybrid automatic repeat indicator channel PHICH in a symbol occupied by a PDCCH for scheduling downlink traffic,Indicating the number of REs occupied by a PCFICH (physical control format indicator channel) in a symbol occupied by a PDCCH (physical control channel) for scheduling downlink services;

the PDCCH can be used for scheduling the number of REs of the uplink service in each VoLTE service periodDetermined according to the following formula:

$\stackrel{\&OverBar;}{N_{RE\_UL}^{CONTROL}}=\underset{k=1}{\overset{P}{\&Sigma;}}(N_{kRE\_UL}^{CONTROL}-N_{kRE\_UL}^{CRS}-N_{kRE\_UL}^{PHICH}-N_{kRE\_UL}^{PCFICH})$

wherein,for the total number of REs in a symbol occupied by PDCCH available for scheduling uplink traffic,the number of REs occupied by CRS channels within symbols occupied by PDCCH for scheduling uplink traffic,The number of REs occupied by the PHICH in the symbol occupied by the PDCCH for scheduling the uplink traffic,The number of REs occupied by PCFICH in a symbol occupied by a PDCCH used for scheduling uplink service;

the cell average CCE aggregation levelDetermined according to the following formula:

$\stackrel{\&OverBar;}{P^{CCE}}=\underset{x=1}{\overset{Q}{\&Sigma;}}{2}^{(x-1)}{P}_x^{CCE}$

wherein x is the aggregation level, Q is the maximum aggregation level,for the proportion of the users distributed under different aggregation levelsDetermined from the MR data.

8. The method according to any one of claims 1 to 7, wherein the U is as defined in_PDSCHThe U_PUSCHThe U_{PDCCH_UL}And the U_{PDCCH_DL}Determining the support capacity of the LTE-TDD cell for the VoLTE service, including:

will be the U_PDSCHThe U_PUSCHThe U_{PDCCH_UL}And the U_{PDCCH_DL}And the medium minimum value is used as the support capacity of the LTE-TDD cell for the VoLTE service.

9. An apparatus for determining LTE-TDD cell traffic support capacity, comprising:

a PDSCH determining module: the method is used for determining the number U of users of the PDSCH capable of supporting the VoLTE service according to the number of downlink available Resource Blocks (RBs), the number of downlink RBs occupied by each VoLTE service on average and a first influence factor_PDSCH；

A PUSCH determination module: for availability according to uplinkThe number of RBs, the number of uplink RBs occupied by each VoLTE service on average and a second influence factor are used for determining the number U of users of PUSCH capable of supporting the VoLTE service_PUSCH；

A PDCCH determination module: the method is used for determining the number U of users for scheduling VoLTE uplink service which can be supported by PDCCH according to the number of Resource Elements (REs) in each VoLTE service period, the polymerization degree of CCE (cell average control channel element) and a third influence factor_{PDCCH_UL}And user number U for scheduling VoLTE downlink service_{PDCCH_DL}；

A result determination module: for according to the U_PDSCHThe U_PUSCHThe U_{PDCCH_UL}And the U_{PDCCH_DL}And determining the support capacity of the LTE-TDD cell to the VoLTE service.

10. The apparatus of claim 9, wherein the PDSCH determining module is further configured to:

determining the number U of users of the PDSCH capable of supporting VoLTE service according to the following formula_PDSCH：

$U_{PDSCH}=\frac{N_{RB}^{DL}\&times;{\mathrm{NB}}_{TTI}^{VoLTE}\&times;(1-F_{\mathrm{Re}trans})\&times;F_{TDD}^{DL}}{\stackrel{\&OverBar;}{N_{DL\_RB}^{VoLTE}}\&times;VAF}$

Wherein,for the number of RBs available for the downlink,for the average number of downlink RBs occupied per VoLTE service,for each number of TTIs in a VoLTE service period, the first impact factor includes: retransmission factor F_RetransDownlink time division duplex TDD factorVoice activation factor VAF.

11. The apparatus of claim 10, wherein the PDSCH determining module is further configured to:

determining the number of downlink RBs occupied by each VoLTE service according to the following formula

$\stackrel{\&OverBar;}{N_{DL\_RB}^{VoLTE}}=\underset{i=1}{\overset{M}{\&Sigma;}}(i\&times;P_i)$

Wherein, M is the maximum allocable downlink RB quantity of the LTE-TDD cell; i is the number of RBs corresponding to different downlink channel quality indicator CQI grades, and the i is determined according to the CQI grades and the size of data to be transmitted; p_iFor the distribution proportion of downlink users corresponding to the RB number i, the P_iDetermining according to the MR data of the cell measurement report;

determining the number of RBs available for downlink according to the following formula

$N_{RB}^{DL}=(N_{RB\_ALL}^{DL}-N_{SIB}-N_{RRC}^{PDSCH}-N_{Paging})$

Wherein,for the total number of RBs in downlink, N_SIBThe number of RBs occupied by the system information block SIB,Number of downlink RBs, N occupied for radio resource control RRC signalling_PagingThe number of RBs occupied for paging.

12. The apparatus of claim 9, wherein the PUSCH determining module is further configured to:

determining the number U of users of the PUSCH capable of supporting VoLTE service according to the following formula_PUSCH：

$U_{PUSCH}=\frac{N_{RB}^{DL}\&times;{\mathrm{NB}}_{TTI}^{VoLTE}\&times;(1-F_{\mathrm{Re}trans})\&times;F_{TDD}^{UL}\&times;F_{PRACH}}{\stackrel{\&OverBar;}{N_{DL\_RB}^{VoLTE}}\&times;VAF}$

Wherein,the number of RBs available for the uplink is,for the average number of uplink RBs occupied by each VoLTE service, the second impact factor includes: retransmission factor F_RetransUplink time division duplex TDD factorPhysical random access channel PRACH factor F_PRACHVoice activation factor VAF.

13. The apparatus of claim 12, wherein the PUSCH determining module is further configured to:

determining the number of uplink RBs occupied by each VoLTE service according to the following formula

$\stackrel{\&OverBar;}{N_{UL\_RB}^{VoLTE}}=\underset{j=1}{\overset{N}{\&Sigma;}}(j\&times;P_j)$

Wherein, N is the maximum allocable uplink RB quantity of the LTE-TDD cell; j is the number of RBs corresponding to different modulation coding strategy MCS levels of the uplink_，The j is determined according to the MCS level and the size of the data to be transmitted; p_jFor the distribution proportion of the uplink users with the RB number j, the P_jDetermining according to the MR data of the cell measurement report;

determining the number of RBs available for uplink according to the following formula

$N_{RB}^{UL}=(N_{RB\_ALL}^{UL}-N_{RB}^{PUCCH}-N_{RRC}^{PUSCH})$

Wherein,for the total number of uplink RBs,The number of RBs occupied by the physical uplink control channel PUCCH,The number of uplink RBs occupied for RRC signaling.

14. The apparatus of claim 9, wherein the number of Resource Elements (REs) in each VoLTE service period includes a number of REs available to the PDCCH for scheduling downlink services in each VoLTE service period and a number of REs available to the PDCCH for scheduling uplink services in each VoLTE service period, and wherein the PDCCH determination module is further configured to:

determining the number U of users which can be supported by the PDCCH for scheduling VoLTE downlink service according to the following formula_{PDCCH_DL}：

$U_{PDCCH\_DL}=\frac{ROUNDUP(\stackrel{\&OverBar;}{N_{RE\_DL}^{CONTROL}}/R)\&times;(1-F_{\mathrm{Re}trans})\&times;F_{SPS}}{\stackrel{\&OverBar;}{P^{CCE}}\&times;VAF}$

Determining the number U of users which can be supported by the PDCCH for scheduling VoLTE uplink service according to the following formula_{PDCCH_UL}：

$U_{PDCCH\_UL}=\frac{ROUNDUP(\stackrel{\&OverBar;}{N_{RE\_UL}^{CONTROL}}/R)\&times;(1-F_{\mathrm{Re}trans})\&times;F_{SPS}}{\stackrel{\&OverBar;}{P^{CCE}}\&times;VAF}$

Where R is the number of REs available per CCE,for the number of REs that can be used for scheduling downlink services in the PDCCH in each VoLTE service period,For the number of REs available for the PDCCH to schedule uplink traffic in each VoLTE traffic period,is the cell average CCE aggregation level; the third influencing factor comprises: heavy loadFactor F_RetransSemi-persistent scheduling (SPS) gain F_SPSVoice activation factor VAF.

15. The apparatus of claim 14, wherein the PDCCH determination module is further configured to:

determining the number of REs which can be used for scheduling downlink service by PDCCH in each VoLTE service period according to the following formula

$\stackrel{\&OverBar;}{N_{RE\_DL}^{CONTROL}}=\underset{k=1}{\overset{P}{\&Sigma;}}(N_{kRE\_DL}^{CONTROL}-N_{kRE\_DL}^{CRS}-N_{kRE\_DL}^{PHICH}-N_{kRE\_DL}^{PCFICH})$

Wherein k is the subframe number in each VoLTE service period, P is the maximum subframe number in each VoLTE service period,the total number of REs in a symbol occupied for PDCCH available for scheduling downlink traffic,the number of REs occupied by a Cell Reference Signal (CRS) channel in a symbol occupied by a PDCCH for scheduling downlink traffic,The number of REs occupied by a physical hybrid automatic repeat indicator channel PHICH in a symbol occupied by a PDCCH for scheduling downlink traffic,Indicating the number of REs occupied by a PCFICH (physical control format indicator channel) in a symbol occupied by a PDCCH (physical control channel) for scheduling downlink services;

determining the number of REs which can be used for scheduling uplink service by PDCCH in each VoLTE service period according to the following formula

$\stackrel{\&OverBar;}{N_{RE\_UL}^{CONTROL}}=\underset{k=1}{\overset{P}{\&Sigma;}}(N_{kRE\_UL}^{CONTROL}-N_{kRE\_UL}^{CRS}-N_{kRE\_UL}^{PHICH}-N_{kRE\_UL}^{PCFICH})$

Wherein,for the total number of REs in a symbol occupied by PDCCH available for scheduling uplink traffic,the number of REs occupied by CRS channels within symbols occupied by PDCCH for scheduling uplink traffic,The number of REs occupied by the PHICH in the symbol occupied by the PDCCH for scheduling the uplink traffic,The number of REs occupied by PCFICH in a symbol occupied by a PDCCH used for scheduling uplink service;

determining the cell average CCE aggregation level according to the following formula

$\stackrel{\&OverBar;}{P^{CCE}}=\underset{x=1}{\overset{Q}{\&Sigma;}}{2}^{(x-1)}{P}_x^{CCE}$

Wherein x is the aggregation level, Q is the maximum aggregation level,for the proportion of the users distributed under different aggregation levelsDetermined from the MR data.

16. The apparatus of any of claims 9-15, wherein the result determination module is further configured to:

will be the U_PDSCHThe U_PUSCHThe U_{PDCCH_UL}And the U_{PDCCH_DL}And the medium minimum value is used as the support capacity of the LTE-TDD cell for the VoLTE service.