CN102469571B - Method and system for realizing delay compensation in distributed base station system - Google Patents

Abstract

The invention discloses a method and a system for realizing delay compensation in a distributed base station system. The method comprises the following steps that: a base band unit (BBU) determines a time advance interval T for sending downlink data, and sends the downlink data in the time advance interval T prior to the timing time of the whole network; and after receiving the downlink data, each remote radio unit (RRU) sends the downlink data to a null interface in a delayed mode, so that the downlink data sent by each RRU arrives at the null interface at the same time, wherein duration for sending downlink data delay is a value obtained by subtracting downlink delay duration TDL between the BBU and each RRU from the time advance interval T. By the method and the system, a scheme for measuring and compensating link transmission and delay processing when a base band radio frequency interface is implemented by a common public radio interface (CPRI) protocol standard in a long term evolution (LTE) system is provided.

Description

A kind of method and system that realize delay compensation in distributed base station system

Technical field

The present invention relates to a kind of distributed base station system, relate in particular to a kind of method and system that realize delay compensation in distributed base station system.

Background technology

Distribution-type base station architecture has become a development trend of wireless communication system, can be by Base Band Unit (Base Band Unit based on this framework, be called for short BBU) and radio frequency unit (Remote Radio Unit, be called for short RRU) separate, independently develop, thereby reduce development cost, improved networking flexibility.Application common radio-frequency interface (Common Public Radio Interface, be called for short CPRI) in the field of wireless communication of consensus standard, Base Band Unit is called to REC (Radio Equipment Control), RRU is called to RE (Radio Equipment).

In distribution-type base station architecture, BBU and RRU generally zoom out formula layout by optical fiber or other cable, and zooming out distance can be up to several kilometer, even tens of kilometers.Because the transmission range between BBU and RRU is different, or the standard difference of RRU, cause BBU transmitted signal after link transmission and RRU processing, to send to the asynchronism(-nization) step of eating dishes without rice or wine, thereby can cause the Problem of Frame Synchronization of system group network.For reverse link, RRU receives and eats dishes without rice or wine after signal, and through processing and the link transmission of RRU, the moment that arrives BBU is also different, thereby can increase the processing complexity of BBU.

CPRI agreement is defined each node time delay of the distributed base station system based on its structure, and has provided a kind of method of measurement.In CPRI agreement, for the measurement of time delay based on frame timing (FrameTiming).Use CPRI interface in different communication systems time, the measurement of time delay is slightly different, especially for FDD and TDD system, because the delay requirement of two kinds of systems is not quite similar.In addition, CPRI agreement is not clearly described delay compensation method.

Generally, various communication systems, no matter concrete communication standard, has the concept of wireless frame format.In the time of combining wireless frame format and CPRI protocol frame format, how to carry out delay compensation and become the problem that needs solve.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of method and system that realize delay compensation in distributed base station system, has solved under LTE standard, while using CPRI consensus standard to realize base band radio frequency interface, and the compensation problem of link transmission and processing time delay.

In order to solve the problems of the technologies described above, the invention provides a kind of method that realizes delay compensation in distributed base station system, comprise: Base Band Unit is identified for sending the time advance interval T of downlink data, and send downlink data in the whole network timing in advance with described time advance interval T, each radio frequency unit is received after described downlink data, the downlink data that each radio frequency unit is sent to the time delay transmission downlink data of eating dishes without rice or wine arrives and eats dishes without rice or wine simultaneously, the duration that sends downlink data time delay is that the down link that described time advance interval T deducts between Base Band Unit and radio frequency unit postpones duration T _dLvalue.

Further, said method can also have following characteristics:

Downlink data reaches after air interface synchronization, and radio frequency unit is sent to Base Band Unit after to the upstream data time delay T1 receiving, and Base Band Unit is according to the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate after processing, obtain the ascending idle port data that each radio frequency unit sends simultaneously.

Further, said method can also have following characteristics:

Time advance interval T is relevant with the processing time delay of length for connecting the optical fiber between described Base Band Unit and radio frequency unit and radio frequency unit.

Further, said method can also have following characteristics:

Down link between Base Band Unit and radio frequency unit postpones duration T _dLrefer to that Base Band Unit sends data to radio frequency unit and sent to by radio frequency unit the time delay of the process of eating dishes without rice or wine, occurrence is:

$T_{\mathrm{DL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]+\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+T2a\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; T2a refers to that radio frequency unit receives data to these data being sent to the duration of eating dishes without rice or wine from base band radio frequency interface down link.

Further, said method can also have following characteristics:

Downlink data reaches after air interface synchronization, and radio frequency unit does not carry out delay process to be directly sent to Base Band Unit be that T1 value is 0 o'clock receiving uplink data, and Base Band Unit is with the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate processing; Uplink delay duration T between Base Band Unit and radio frequency unit _uLrefer to that radio frequency unit receives after upstream data the time delay of receiving the upstream data that radio frequency unit sends to Base Band Unit, occurrence is:

$T_{\mathrm{UL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]-\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+\mathrm{Ta}3\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; Ta3 refers to that radio frequency unit receives data to the duration that these data is sent to base band radio frequency interface up link from eating dishes without rice or wine.

Further, said method can also have following characteristics:

When radio frequency unit carries out delay process to ascending idle port data, the duration T1 of time delay is that the maximum of uplink delay duration between Base Band Unit and each radio frequency unit deducts the Base Band Unit difference of uplink delay duration between radio frequency unit therewith:

Base Band Unit is with the maximum of uplink delay duration between Base Band Unit and each radio frequency unit

the ascending idle port data that each radio frequency unit is sent compensate processing.

In order to solve the problems of the technologies described above, the present invention also provides a kind of system that realizes delay compensation in distributed base station system, comprises Base Band Unit and radio frequency; Described Base Band Unit, for being identified for sending the time advance interval T of downlink data, and sends downlink data in the whole network timing in advance with described time advance interval T; Described radio frequency unit, for receiving after described downlink data, to eating dishes without rice or wine, time delay sends downlink data, the downlink data that each radio frequency unit is sent arrives and eats dishes without rice or wine simultaneously, and the duration that sends downlink data time delay is that described time advance interval T deducts the link downlink delays duration T between Base Band Unit and radio frequency unit _dLvalue.

Further, said system can also have following characteristics:

Described radio frequency unit, for reaching after air interface synchronization at downlink data, to being sent to Base Band Unit after the upstream data time delay T1 receiving; Described Base Band Unit, for according to the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate after processing, obtain the ascending idle port data that each radio frequency unit sends simultaneously.

Further, said system can also have following characteristics:

Down link between described Base Band Unit and radio frequency unit postpones duration T _dLrefer to that Base Band Unit sends data to radio frequency unit and sent to by radio frequency unit the time delay of the process of eating dishes without rice or wine, occurrence is:

$T_{\mathrm{DL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]+\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+T2a\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; T2a refers to that radio frequency unit receives data to these data being sent to the duration of eating dishes without rice or wine from base band radio frequency interface down link.

Further, said system can also have following characteristics:

Described Base Band Unit, also for reaching after air interface synchronization at downlink data, radio frequency unit does not carry out delay process to be directly sent to Base Band Unit is that T1 value is 0 o'clock receiving uplink data, with the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate processing; Uplink delay duration TUL between Base Band Unit and radio frequency unit refers to that radio frequency unit receives after upstream data the time delay of receiving the upstream data that radio frequency unit sends to Base Band Unit, and occurrence is:

$T_{\mathrm{UL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]-\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+\mathrm{Ta}3\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; Ta3 refers to that radio frequency unit receives data to the duration that these data is sent to base band radio frequency interface up link from eating dishes without rice or wine.

Further, said system can also have following characteristics:

Described radio frequency unit, also the duration T1 of time delay is that the maximum of uplink delay duration between Base Band Unit and each radio frequency unit deducts the Base Band Unit difference of uplink delay duration between radio frequency unit therewith when ascending idle port data are carried out to delay process:

Described Base Band Unit, also for the maximum with uplink delay duration between Base Band Unit and each radio frequency unit

the ascending idle port data that each radio frequency unit is sent compensate processing.

The present invention is applicable to Long Term Evolution (Long Term Evolution is called for short LTE) system, comprises two kinds of standards of LTE-FDD and LTE-TDD.The invention solves under LTE standard link transmission and the processing measurement of time delay and the scheme of compensation while using CPRI consensus standard to realize base band radio frequency interface.The method that the present invention proposes, clear and definite used CPRI interface to complete transmission between Base Band Unit and radio frequency unit and is processing measurement and the compensation method of time delay.

Brief description of the drawings

Fig. 1 is the system schematic that realizes delay compensation in embodiment in distributed base station system;

Fig. 2 is the method schematic diagram of realizing delay compensation in embodiment in distributed base station system;

Fig. 3 is the schematic diagram that in embodiment, Base Band Unit sends downlink data in advance in the whole network timing with time advance interval T;

Fig. 4 is that Base Band Unit sends downlink data in advance, and the data that radio frequency unit sends send to the schematic diagram that cannot align while eating dishes without rice or wine;

Fig. 5 is that Base Band Unit sends downlink data in advance, the data schematic diagram when eating dishes without rice or wine simultaneously after each radio frequency unit compensates and processes;

Fig. 6 is in up compensation way one, and Base Band Unit carries out can accurately finding out after up compensation of delay the schematic diagram of the starting point of the data of eating dishes without rice or wine;

Fig. 7 is in up compensation way two, and Base Band Unit carries out can accurately finding out after up compensation of delay the schematic diagram of the starting point of the data of eating dishes without rice or wine.

Embodiment

The system that realizes as shown in Figure 1 delay compensation in distributed base station system, comprises Base Band Unit and radio frequency.Described Base Band Unit is used for being identified for sending the time advance interval T of downlink data, and sends downlink data in the whole network timing in advance with described time advance interval T.Described radio frequency unit is for receiving after described downlink data, to eating dishes without rice or wine, time delay sends downlink data, the downlink data that each radio frequency unit is sent arrives and eats dishes without rice or wine simultaneously, and the duration that sends downlink data time delay is that described time advance interval T deducts the link downlink delays duration T between Base Band Unit and radio frequency unit _dLvalue.

Down link between described Base Band Unit and radio frequency unit postpones duration T _dLrefer to that Base Band Unit sends data to radio frequency unit and sent to by radio frequency unit the time delay of the process of eating dishes without rice or wine, occurrence is:

$T_{\mathrm{DL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]+\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+T2a\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; T2a refers to that radio frequency unit receives data to these data being sent to the duration of eating dishes without rice or wine from base band radio frequency interface down link.

Described radio frequency unit is also for reaching after air interface synchronization at downlink data, to being sent to Base Band Unit after the upstream data time delay T1 receiving.Described Base Band Unit is also for according to the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate after processing, obtain the ascending idle port data that each radio frequency unit sends simultaneously.

In up compensation way one, described Base Band Unit is also for reaching after air interface synchronization at downlink data, radio frequency unit does not carry out delay process to be directly sent to Base Band Unit is that T1 value is 0 o'clock receiving uplink data, with the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate processing; Uplink delay duration T between Base Band Unit and radio frequency unit _uLrefer to that radio frequency unit receives after upstream data the time delay of receiving the upstream data that radio frequency unit sends to Base Band Unit, occurrence is:

$T_{\mathrm{UL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]-\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+\mathrm{Ta}3\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; Ta3 refers to that radio frequency unit receives data to the duration that these data is sent to base band radio frequency interface up link from eating dishes without rice or wine.

In up compensation way two, described radio frequency unit also when ascending idle port data are carried out to delay process the duration T1 of time delay be that the maximum of uplink delay duration between Base Band Unit and each radio frequency unit deducts the Base Band Unit difference of uplink delay duration between radio frequency unit therewith:

Described Base Band Unit is also for the maximum with uplink delay duration between Base Band Unit and each radio frequency unit the ascending idle port data that each radio frequency unit is sent compensate processing.

Wherein, the time-delay measuring unit in Base Band Unit and radio frequency unit is for measuring required each parameter value, and the delay compensation unit in Base Band Unit and radio frequency unit is for compensating operation to the data that receive or send.Time-delay calculation unit in Base Band Unit is for shifting to an earlier date interval T and T computing time _dLand T _uL.

As shown in Figure 2, the method that realizes delay compensation in distributed base station system comprises: Base Band Unit is identified for sending the time advance interval T of downlink data, and send downlink data in the whole network timing in advance with described time advance interval T, each radio frequency unit is received after described downlink data, the downlink data that each radio frequency unit is sent to the time delay transmission downlink data of eating dishes without rice or wine arrives and eats dishes without rice or wine simultaneously, and the duration that sends downlink data time delay is that the down link that described time advance interval T deducts between Base Band Unit and radio frequency unit postpones duration T _dLvalue.

When Base Band Unit sends downlink data in advance, by wireless frame data and the binding of CPRI interface frame, the data that first antenna carrier is carried of transmitting in CPRI frame are first sampling point data of this wireless frame data.The frame timing of CPRI interface is not subject to the impact of delay compensation method.BBU and RRU carry out delay compensation by the mode of adjusting business datum original position.

The whole network timing refers to that the whole network is based on GPS (Global Positioning System, global positioning system) or other synchro system, and for example dipper system, can extract the synchronizing function of a timing base for each unit in the whole network.

As shown in Figure 3, Base Band Unit sends downlink data in the whole network timing in advance with described time advance interval T.Wherein, time advance interval T is mainly relevant with the processing time delay of length K for connecting the optical fiber between described Base Band Unit and radio frequency unit and radio frequency unit, K is the comprehensive example of fiber distance between all radio frequency units and Base Band Unit under Base Band Unit, for example mean value.For example, the radio frequency unit of Base Band Unit management support 10 kilometers in time corresponding time advance interval T and Base Band Unit management 20 kilometers of radio frequency unit supports in time corresponding time advance interval T difference larger.When concrete calculating, can adopt the value of T to be taken as

c is the light velocity.Time advance interval T can also be relevant with processing time delay index to downlink transfer, downlink transfer and processing time delay index refer to the transmission of each interdependent node in distributed base station system and process time delay summation index, the base band radio frequency interface that comprises Base Band Unit processing time delay, link transmission time delay, radio frequency unit processing time delay etc.

Radio frequency unit extract antenna data from CPRI interface after, through in/processing of radio circuit, in sending to and eating dishes without rice or wine.Synchronous for ensureing that each radio frequency unit sends to the data of eating dishes without rice or wine, need to carry out compensation of delay processing to downlink data at radio frequency unit.The delay compensation method that this motion proposes is, CPRI interface frame timing data does not compensate processing, the antenna data extracting from CPRI interface is carried out to delay process, and each radio frequency unit carries out the delay process of corresponding delay compensation parameter to antenna data, reach the synchronous object of the data of eating dishes without rice or wine.

Down link between Base Band Unit and radio frequency unit postpones duration T _dLrefer to that Base Band Unit sends data to radio frequency unit and sent to by radio frequency unit the time delay of the process of eating dishes without rice or wine, occurrence is:

$T_{\mathrm{DL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]+\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+T2a\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection, and the index of the radio frequency unit nearest apart from Base Band Unit is 1, then adds successively 1.; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit, there is following calculated relationship with other parameter, T14 (1)=T12 (1)+Toffset (1)+T34 (1), in formula, (1) all represents relevantly with first order radio frequency unit, and for example T12 (1) represents that Base Band Unit is to the down link time delay of first order radio frequency unit; Tofffset refer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _creferring to the duration of a basic frame in CPRI link, is a fixed value, and size is (1/3840000) s; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; T2a refers to that radio frequency unit receives data to these data being sent to the duration of eating dishes without rice or wine from base band radio frequency interface down link.

Typically, T _dL(i) can also get following representative value:

$T_{\mathrm{DL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+T2a\left(i\right)$

In above formula, each parameter value is defined parameter in prior art.The each node specifying in CPRI agreement transmits or processes Time delay measurement.Base Band Unit carries wireless frame data with on corresponding CPRI frame, and has worked in coordination with the transmission of each node or the collection of processing delay by Base Band Unit and radio frequency unit.Radio frequency unit completes the measurement of T2a, the Ta3, Toffset, TBdl, TBul and the N value that specify in CPRI agreement, and measurement result is transferred to Base Band Unit by CPRI interface.Base Band Unit completes the measurement of Base Band Unit to the loop time delay T14 (1) of radio frequency unit according to the uplink/downlink frames timing of CPRI interface.

As shown in Figure 4, Base Band Unit sends downlink data in advance, supposes the uplink downlink time delay difference of each radio frequency unit, and radio frequency unit sends to data while eating dishes without rice or wine so, just can not complete the data of eating dishes without rice or wine synchronous.

As shown in Figure 5, after the descending delay compensation of radio frequency unit, downlink data is completed synchronously in the data of eating dishes without rice or wine.

In said method, also comprise upward signal processing procedure: downlink data reaches after air interface synchronization, radio frequency unit is sent to Base Band Unit after to the upstream data time delay T1 receiving, and Base Band Unit is according to the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate after processing, obtain the ascending idle port data that each radio frequency unit sends simultaneously.

When up compensation, can adopt the one in following up compensation way:

Up compensation way one:

The ascending idle port data that radio frequency unit receives, are carried on CPRI interface and are transferred to Base Band Unit.Correct for ensureing upstream data processing, Base Band Unit need to be found out the starting point of the wireless frame data of eating dishes without rice or wine.In this motion, Base Band Unit is eated dishes without rice or wine timing as benchmark taking system, according to the up Time delay measurement result of calculation T that measures the each radio frequency unit calculating _uLcarry out compensation of delay, can accurately find out the starting point of the data of eating dishes without rice or wine., as shown in Figure 6.Upstream data after compensation can carry out follow-up dependency basis tape handling.

Downlink data reaches after air interface synchronization, and radio frequency unit does not carry out delay process to reception uplink data and is directly sent to Base Band Unit, and Base Band Unit is with the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate processing; Uplink delay duration T between Base Band Unit and radio frequency unit _uLrefer to that radio frequency unit receives after upstream data the time delay of receiving the upstream data that radio frequency unit sends to Base Band Unit, occurrence is:

$T_{\mathrm{UL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]-\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+\mathrm{Ta}3\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection, and the index of the radio frequency unit nearest apart from Base Band Unit is 1, then adds successively 1.Sequence number value; T14 (1) refers to that Base Band Unit arrives the loop time delay of first order radio frequency unit, there is following calculated relationship with other parameter, T14 (1)=T12 (1)+Toffset (1)+T34 (1), in formula, (1) all represents relevantly with first order radio frequency unit, and for example T12 (1) represents that Base Band Unit is to the down link time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _creferring to the duration of a basic frame in CPRI link, is a fixed value, and size is (1/3840000) s; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; Ta3 refers to that radio frequency unit receives data to the duration that these data is sent to base band radio frequency interface up link from eating dishes without rice or wine.

Typically, T _uL(i) can also get following representative value:

$T_{\mathrm{UL}}\left(i\right)=\frac{T14\left(l\right)-\mathrm{Toffset}\left(i\right)}{2}+\mathrm{Ta}3\left(i\right)$

Up compensation way two:

Radio frequency unit receives after upstream data, first carry out up time delay alignment compensation, when radio frequency unit carries out delay process to ascending idle port data, the duration T1 of time delay is that the maximum of T 2 of the uplink delay duration between Base Band Unit and each radio frequency unit deducts the Base Band Unit difference of the uplink delay duration between radio frequency unit therewith:

After this compensation, when under Base Band Unit, each radio frequency unit upstream data sends to Base Band Unit, arrive simultaneously.Base Band Unit is based on timing, with the maximum of the uplink delay duration between Base Band Unit and each radio frequency unit

the ascending idle port data that to be T2 send each radio frequency unit compensate processing, can obtain the ascending idle port wireless data of each radio frequency unit after synchronous, as shown in Figure 7.

It should be noted that, in the situation that not conflicting, the combination in any mutually of the feature in embodiment and embodiment in the application.

Certainly; the present invention also can have other various embodiments; in the situation that not deviating from spirit of the present invention and essence thereof; those of ordinary skill in the art are when making according to the present invention various corresponding changes and distortion, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

One of ordinary skill in the art will appreciate that all or part of step in said method can carry out instruction related hardware by program and complete, described program can be stored in computer-readable recording medium, as read-only memory, disk or CD etc.Alternatively, all or part of step of above-described embodiment also can realize with one or more integrated circuits.Correspondingly, the each module/unit in above-described embodiment can adopt the form of hardware to realize, and also can adopt the form of software function module to realize.The present invention is not restricted to the combination of the hardware and software of any particular form.

Claims (9)

1. a method that realizes delay compensation in distributed base station system, is characterized in that,

Base Band Unit is identified for sending the time advance interval T of downlink data, and send downlink data in the whole network timing in advance with described time advance interval T, each radio frequency unit is received after described downlink data, the downlink data that each radio frequency unit is sent to the time delay transmission downlink data of eating dishes without rice or wine arrives and eats dishes without rice or wine simultaneously, and the duration that sends downlink data time delay is that the down link that described time advance interval T deducts between Base Band Unit and radio frequency unit postpones duration T _dLvalue;

Downlink data reaches after air interface synchronization, and radio frequency unit is sent to Base Band Unit after to the upstream data time delay T1 receiving, and Base Band Unit is according to the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate after processing, obtain the ascending idle port data that each radio frequency unit sends simultaneously.

2. the method for claim 1, is characterized in that,

Time advance interval T is relevant with the processing time delay of length for connecting the optical fiber between described Base Band Unit and radio frequency unit and radio frequency unit.

3. the method for claim 1, is characterized in that,

Down link between Base Band Unit and radio frequency unit postpones duration T _dLrefer to that Base Band Unit sends data to radio frequency unit and sent to by radio frequency unit the time delay of the process of eating dishes without rice or wine, occurrence is:

$T_{\mathrm{DL}}\left(i\right)=\frac{T14\left(1\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]+\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+T2a\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14(1) refer to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; T2a refers to that radio frequency unit receives data to these data being sent to the duration of eating dishes without rice or wine from base band radio frequency interface down link.

4. the method for claim 1, is characterized in that,

Downlink data reaches after air interface synchronization, and radio frequency unit does not carry out delay process to be directly sent to Base Band Unit be that T1 value is 0 o'clock receiving uplink data, and Base Band Unit is with the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate processing; Uplink delay duration T between Base Band Unit and radio frequency unit _uLrefer to that radio frequency unit receives after upstream data the time delay of receiving the upstream data that radio frequency unit sends to Base Band Unit, occurrence is:

$T_{\mathrm{UL}}\left(i\right)=\frac{T14\left(1\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]-\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+\mathrm{Ta}3\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14(1) refer to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; Ta3 refers to that radio frequency unit receives data to the duration that these data is sent to base band radio frequency interface up link from eating dishes without rice or wine.

5. the method for claim 1, is characterized in that,

When radio frequency unit carries out delay process to ascending idle port data, the duration T1 of time delay is that the maximum of uplink delay duration between Base Band Unit and each radio frequency unit deducts the Base Band Unit difference of uplink delay duration between radio frequency unit therewith:

Wherein, j represents the progression index of the radio frequency unit of Base Band Unit connection;

Base Band Unit is with the maximum of uplink delay duration between Base Band Unit and each radio frequency unit the ascending idle port data that each radio frequency unit is sent compensate processing.

6. a system that realizes delay compensation in distributed base station system, comprises Base Band Unit and radio frequency unit, it is characterized in that,

Described Base Band Unit, for being identified for sending the time advance interval T of downlink data, and sends downlink data in the whole network timing in advance with described time advance interval T;

Described radio frequency unit, for receiving after described downlink data, to eating dishes without rice or wine, time delay sends downlink data, the downlink data that each radio frequency unit is sent arrives and eats dishes without rice or wine simultaneously, and the duration that sends downlink data time delay is that described time advance interval T deducts the link downlink delays duration T between Base Band Unit and radio frequency unit _dLvalue;

Described radio frequency unit, for reaching after air interface synchronization at downlink data, to being sent to Base Band Unit after the upstream data time delay T1 receiving;

Described Base Band Unit, for according to the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate after processing, obtain the ascending idle port data that each radio frequency unit sends simultaneously.

7. system as claimed in claim 6, is characterized in that,

Down link between described Base Band Unit and radio frequency unit postpones duration T _dLrefer to that Base Band Unit sends data to radio frequency unit and sent to by radio frequency unit the time delay of the process of eating dishes without rice or wine, occurrence is:

$T_{\mathrm{DL}}\left(i\right)=\frac{T14\left(1\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]+\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+T2a\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14(1) refer to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; T2a refers to that radio frequency unit receives data to these data being sent to the duration of eating dishes without rice or wine from base band radio frequency interface down link.

8. system as claimed in claim 6, is characterized in that,

Described Base Band Unit, also for reaching after air interface synchronization at downlink data, radio frequency unit does not carry out delay process to be directly sent to Base Band Unit is that T1 value is 0 o'clock receiving uplink data, with the uplink delay duration T between Base Band Unit and radio frequency unit _uLthe ascending idle port data that each radio frequency unit is sent compensate processing; Uplink delay duration T between Base Band Unit and radio frequency unit _uLrefer to that radio frequency unit receives after upstream data the time delay of receiving the upstream data that radio frequency unit sends to Base Band Unit, occurrence is:

$T_{\mathrm{UL}}\left(i\right)=\frac{T14\left(1\right)-\mathrm{Toffset}\left(i\right)}{2}+\frac{\mathrm{Tc}}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}\left[N\left(k\right)\right]-\frac{1}{2}\underset{k=0}{\overset{i-1}{\mathrm{\Σ}}}[\mathrm{TBdl}\left(k\right)-\mathrm{TBul}\left(k\right)]+\mathrm{Ta}3\left(i\right)$

Wherein, i represents the progression index of the radio frequency unit of Base Band Unit connection; T14(1) refer to that Base Band Unit arrives the loop time delay of first order radio frequency unit; T _offsetrefer to radio frequency unit from base band radio frequency interface down link extract Timing Synchronization signal time be carved into the interval duration using this Timing Synchronization signal as uplink timing synchronizing signal; T _crefer to the duration of the basic frame of common radio-frequency interface link; When N value refers to that radio frequency unit receives up link data and sends to base band radio frequency interface and the basic frame difference of uplink timing synchronizing signal; TBdl refers in cascade network configuration mode, and radio frequency unit receives data to the forwarding duration that these data is sent to the base band radio frequency interface being connected with next stage radio frequency unit from the base band radio frequency interface down link being connected with even higher level of node; TBul refers in cascade network configuration mode, and radio frequency unit receives data from the base band radio frequency interface up link being connected with next stage node, to these data being issued and the forwarding duration of the base band radio frequency interface of even higher level of node; Ta3 refers to that radio frequency unit receives data to the duration that these data is sent to base band radio frequency interface up link from eating dishes without rice or wine.

9. system as claimed in claim 6, is characterized in that,

Described radio frequency unit, also the duration T1 of time delay is that the maximum of uplink delay duration between Base Band Unit and each radio frequency unit deducts the Base Band Unit difference of uplink delay duration between radio frequency unit therewith when ascending idle port data are carried out to delay process:

Wherein, j represents the progression index of the radio frequency unit of Base Band Unit connection;

Described Base Band Unit, also for the maximum with uplink delay duration between Base Band Unit and each radio frequency unit the ascending idle port data that each radio frequency unit is sent compensate processing.

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