CN105682214B

CN105682214B - Baseband and radio frequency combined time sequence adjusting method and device

Info

Publication number: CN105682214B
Application number: CN201410675799.4A
Authority: CN
Inventors: 何勃; 张凯敏; 宋春辉
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2014-11-21
Filing date: 2014-11-21
Publication date: 2020-01-24
Anticipated expiration: 2034-11-21
Also published as: WO2016078401A1; CN105682214A

Abstract

The invention discloses a timing sequence adjusting method and a timing sequence adjusting device combining a baseband and a radio frequency, wherein each adjusting period comprises the following steps: detecting a receiving time sequence and a transmitting time sequence of data, and obtaining a receiving time sequence offset and a transmitting time sequence offset of a baseband processing unit (BBU) and a receiving time sequence offset and a transmitting time sequence offset of a Radio Remote Unit (RRU); generating a common radio interface CPRI frame header, and acquiring the offset of an air interface frame header; acquiring a data receiving adjustment amount and a data transmitting adjustment amount corresponding to baseband processing according to the receiving timing sequence offset, the transmitting timing sequence offset and the offset of an air interface frame header of the BBU; adjusting a receiving frame header and a transmitting frame header of the baseband processing, and adjusting a data stream of the baseband processing; and outputting the CPRI frame header, the RRU receiving time sequence offset, the transmitting time sequence offset, the data receiving adjustment quantity, the data transmitting adjustment quantity and the adjusted data stream. The method can maintain the timing sequence drift caused by the movement of the terminal and the crystal oscillator frequency offset in real time.

Description

Baseband and radio frequency combined time sequence adjusting method and device

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a timing adjustment method and apparatus for combining baseband and radio frequency.

Background

In a wireless system, a Base station device usually adopts a separate structure design of a Base Band Unit (BBU) and a Radio Remote Unit (RRU).

Ground-air communication terminals in the related art, such as CPE (Customer Premise Equipment), Relay, test terminal Equipment and other terminal side Equipment requiring special requirements; terminal-side devices such as ground-air communications; CPE and Relay for realizing backhaul function and edge coverage; and terminal equipment specially used for drive test and test.

Such terminal side equipment needs to support functions such as high-power transmission, long-distance communication, special test functions, special performance indexes and the like, and therefore, such equipment also usually adopts a BBU and RRU separated design of a base station.

The terminal side equipment needs to ensure the separation of the receiving and transmitting frame headers and the synchronization with the air interface of the base station side. And due to factors such as high-speed movement of the terminal equipment, asynchrony between the crystal oscillator and the base station caused by no GPS and the like, the frame head of the receiving and transmitting frame has large-range real-time drift.

For the above situation, the base station device with the BBU and RRU separated structure needs to perform clock calibration and air interface timing adjustment according to a GPS (global positioning System); the terminal side equipment needs the BBU to adjust data and time sequence in real time; a Time Division Duplex (TDD) system RRU needs to switch between receiving and transmitting according to a Time sequence; the RRU needs to perform power statistics, standing-wave ratio detection, and the like according to a timing sequence.

As shown in fig. 1, a common BBU and RRU timing adjustment processing flow includes 3 parts, which are a frame header adjustment process, a receiving process, and a transmitting process.

The frame header adjustment processing flow comprises the following steps:

step S101: searching a GPS signal, performing clock phase discrimination according to a PP1S (Pulse per 1 second) signal recovered by the GPS after the GPS is locked, and obtaining an accurate 10MHz clock after the clock phase discrimination;

step S102: the BBU generates a 10ms signal according to the calibrated 10MHz clock, and generates an air interface 10ms signal according to the PP1S signal of the GPS. Generating a 10ms signal used as a CPRI (Common public radio Interface) frame header according to baseband and radio frequency processing time delay;

the emission processing flow comprises the following steps:

step S103: the BBU high layer starts service scheduling, and a baseband system is scheduled to start a service process;

step S104: the base band system carries out base band processing according to high-level scheduling, respectively completes bit level processing and symbol level processing, and then carries out signal processing of a frequency domain and a time domain;

step S105: after the baseband processing is completed, time domain data needs to be cached, service scheduling data is aligned with a transmitted CPRI frame header, and the data is transmitted to the RRU through a CPRI interface according to the CPRI frame header;

step S106: on the CPRI receiving side of the RRU, the frame header of the CPRI needs to be recovered, and the base band time domain data is received according to the CPRI frame header;

step S107: the received baseband time domain data needs to be subjected to data caching, and the intermediate frequency processing starting time is calculated according to different bandwidths, processing time delay and the like;

step S108: the intermediate frequency link processes the baseband data, and intermediate frequency digital signals are obtained after interpolation, filtering and spectrum shifting of several stages respectively;

step S109: the TDD system needs to turn off an LNA (Low Noise Amplifier ) and turn on a PA (Power Amplifier) according to an idle frame header restored by a GPS (global positioning system) and then sends out the radio frequency signal, wherein the intermediate frequency Digital signal is processed by a radio frequency circuit such as a DAC (Digital to analog converter);

the receiving processing flow comprises the following steps:

step S110: and the RRU receives the analog signal according to the air interface frame head recovered by the GPS, and the TDD system needs to close the low-noise amplifier LNA and open the PA according to the air interface time sequence. Then, the radio frequency signal is subjected to radio frequency link and digital/analog AD conversion to obtain an intermediate frequency digital signal;

step S112: after the radio frequency link carries out operations such as spectrum shifting, sampling, filtering and the like, the radio frequency digital signal is processed into baseband time domain data;

step S113: the time domain data needs to be cached, and the frame header time of the CPRI is waited for;

step S114: after a CPRI frame header arrives, the RRU reads out the time domain data, and sends the time domain data to the BBU through a CPRI interface;

step S115: the BBU side performs data fetching operation according to the CPRI frame header to obtain time domain data aligned with an air interface;

step S116: the time domain data needs to be processed in a time domain and a frequency domain, and is processed in a symbol level and a bit level to obtain service data of a baseband;

step S117: and after the baseband processing is finished, reporting the service data to a high layer.

For the base station side equipment, the existing method needs a complex air interface and CPRI frame header adjustment method, and needs a large amount of data caching components.

For terminal side equipment, GPS does not exist for clock calibration, and frame header drift can be caused by frequency offset of a terminal and a base station crystal oscillator; the GPS does not perform the time sequence synchronization of PP1S, and the terminal side needs to perform air interface synchronization according to a protocol, and the synchronization can drift due to the algorithm precision; the terminal side is matched with the base station side time sequence, and delayed receiving and advanced transmitting exist, so that the received and transmitted frame headers are different; the fixed relation between an air interface and a CPRI frame header does not exist, the CPRI frame header is fixed, and the frame header of the air interface drifts; the position of the terminal equipment moves, and the early and late drift of the frame headers of receiving and transmitting is generated.

Disclosure of Invention

In order to solve the above problems, the present invention provides a timing adjustment method and apparatus combining a baseband and a radio frequency, which can maintain the mobile and crystal oscillator frequency offsets of a terminal in real time.

In order to achieve the above object, the present invention provides a method for adjusting a timing of a baseband, comprising, in each adjustment period:

detecting a receiving time sequence and a transmitting time sequence of data, and obtaining a receiving time sequence offset and a transmitting time sequence offset of a baseband processing unit (BBU) and a receiving time sequence offset and a transmitting time sequence offset of a Radio Remote Unit (RRU);

generating a Common Public Radio Interface (CPRI) frame header, and acquiring the offset of an air interface frame header;

acquiring a data receiving adjustment amount and a data transmitting adjustment amount corresponding to baseband processing according to the receiving timing sequence offset, the transmitting timing sequence offset and the offset of an air interface frame header of the BBU;

adjusting a receiving frame header and a transmitting frame header of the baseband processing, and adjusting a data stream of the baseband processing;

and outputting the CPRI frame header, the RRU receiving time sequence offset, the transmitting time sequence offset, the data receiving adjustment quantity, the data transmitting adjustment quantity and the adjusted data stream.

Further, the method for obtaining the receiving timing offset and the transmitting timing offset of the baseband processing unit BBU and the receiving timing offset and the transmitting timing offset of the remote radio unit RRU includes one of the following: GPS detection, air interface synchronous detection and fine adjustment detection.

Further, obtaining a receiving timing offset and a transmitting timing offset of the baseband processing unit BBU and a receiving timing offset and a transmitting timing offset of the remote radio unit RRU includes:

BBU receiving timing offset T_{bbu_rx}And a transmission timing offset T_{bbu_tx}Is denoted by T_{bbu_tx}＝T_{bbu_rx}-T_2a-T_a3-TA；

RRU receiving time sequence offset T_{rru_rx}＝T_{bbu_rx}-T_a3-T₁₂And a transmission timing offset T_{rru_tx}＝T_{bbu_rx}+T_2a-T₁₂；

Wherein the content of the first and second substances,

T₁₂the method comprises the steps of representing transmission delay introduced by CPRI of BBU and RRU;

T_2arepresenting the processing time delay from the CPRI port time domain data of the RRU to the radio frequency signal of the antenna port;

T_a3representing the processing time delay from the radio frequency signal of the antenna port of the RRU to the time domain data of the CPRI port;

TA denotes the round-trip air-interface delay from the base station to the terminal.

Further, obtaining the adjustment amount of data reception and the adjustment amount of data transmission corresponding to the baseband processing includes:

data receiving adjustment quantity T corresponding to baseband processing_{rx_adj}And the adjustment amount T of data transmission_{tx_adj}Expressed as: t is_{bbu_rx}＝T_{bbu_rx}+T_{rx_adj}；T_{bbu_tx}＝T_{bbu_tx}+T_{tx_adj}；

T′_{bbu_rx}Representing BBUT_periWhen the time sequence is finely adjusted periodically, the time sequence offset of a receiving link of the previous period is adjusted;

T′_{bbu_tx}representing BBUT_periWhen the time sequence is finely adjusted periodically, the time sequence offset of a transmitting link in the previous period is adjusted;

T_periindicating the time period during which the periodic timing is fine-tunedAnd (4) period.

In order to achieve the above object, the present invention further provides a method for adjusting a radio frequency timing sequence, which includes, in each adjustment period:

receiving a Common Public Radio Interface (CPRI) frame header, a Radio Remote Unit (RRU) receiving timing sequence offset, a transmitting timing sequence offset, a data receiving adjustment amount, a data transmitting adjustment amount and a data flow;

recovering the CPRI frame header;

generating a receiving frame header, a transmitting frame header and a data frame header for radio frequency processing on the basis of the CPRI recovery frame header according to the RRU receiving timing sequence offset and the transmitting timing sequence offset;

and outputting the processed intermediate frequency or zero intermediate frequency data.

In order to achieve the above object, the present invention further provides a baseband timing adjustment apparatus, including:

the timing sequence detection module is used for detecting a receiving timing sequence and a transmitting timing sequence of data to obtain a receiving timing sequence offset and a transmitting timing sequence offset of a baseband processing unit (BBU) and a receiving timing sequence offset and a transmitting timing sequence offset of a Radio Remote Unit (RRU);

a frame header generation module: for generating a Common Public Radio Interface (CPRI) frame header;

the timing sequence calculation module is used for obtaining the offset of an air interface frame header and obtaining a data receiving adjustment amount and a data transmitting adjustment amount corresponding to baseband processing according to the receiving timing sequence offset, the transmitting timing sequence offset and the offset of the air interface frame header of the BBU;

the first time sequence adjusting module is used for adjusting a receiving frame header and a transmitting frame header of the baseband processing and adjusting a data stream of the baseband processing;

and the first interface module is used for outputting the CPRI frame header, the RRU receiving time sequence offset, the transmitting time sequence offset, the data receiving adjustment quantity, the data transmitting adjustment quantity and the adjusted data stream.

Preferably, the method for the timing detection module to obtain the receiving timing offset and the transmitting timing offset of the baseband processing unit BBU and the receiving timing offset and the transmitting timing offset of the remote radio unit RRU includes one of the following: GPS detection, air interface synchronous detection and fine adjustment detection.

Preferably, the obtaining, by the timing detection module, the receiving timing offset and the transmitting timing offset of the BBU, and the receiving timing offset and the transmitting timing offset of the RRU includes:

BBU receiving timing offset T_{bbu_rx}And a transmission timing offset T_{bbu_tx}Is denoted by T_{bbu_tx}＝T_{bbu_rx}-T_2a-T_a3-TA；；

Wherein the content of the first and second substances,

Preferably, the obtaining, by the timing calculation module, the data receiving adjustment amount and the data transmitting adjustment amount corresponding to the baseband processing includes:

data receiving adjustment quantity T corresponding to baseband processing_{rx_adj}And the adjustment amount T of data transmission_{tx_adj}Expressed as: t is_{bbu_rx}＝T′_{bbu_rx}+T_{rx_adj}；T_{bbu_tx}＝T′_{bbu_tx}+T_{tx_adj}；

T_periindicating the time period when the cycle timing is fine-tuned.

In order to achieve the above object, the present invention further provides a radio frequency timing adjustment apparatus, including:

the second interface module is used for receiving a common public radio interface CPRI frame header, a radio remote unit RRU receiving time sequence offset, a transmitting time sequence offset, a data receiving adjustment amount, a data transmitting adjustment amount and a data flow;

a frame header recovery module, configured to recover the CPRI frame header;

the second timing adjustment module is used for generating a receiving frame header, a transmitting frame header and a data frame header for radio frequency processing on the basis of the CPRI recovery frame header according to the RRU receiving timing offset and the transmitting timing offset;

and the receiving and transmitting control module is used for controlling the radio frequency antenna switch and outputting the processed intermediate frequency or zero intermediate frequency data.

Compared with the prior art, the device and the method can simplify the data and time sequence processing flow of the base station equipment, carry out service processing starting time according to the time sequence, achieve running water processing by data processing, and reduce the data storage operation of the BBU and the RRU, thereby reducing the equipment complexity and cost. The method can flexibly adjust the frame header of the terminal equipment, maintain the movement and crystal oscillator frequency offset of the terminal in real time, and is suitable for the separation characteristics of the transmitting and receiving frame headers of the terminal and better adapt to the radio frequency processing functions of terminal pilot frequency switching timing and the like.

Drawings

The accompanying drawings in the embodiments of the present invention are described below, and the drawings in the embodiments are provided for further understanding of the present invention, and together with the description serve to explain the present invention without limiting the scope of the present invention.

FIG. 1 illustrates a prior art timing adjustment method;

FIG. 2 is a schematic diagram of a baseband and RF joint timing adjustment apparatus according to an embodiment of the present invention;

FIG. 3 is a timing diagram illustrating a timing adjustment method according to an embodiment of the invention;

FIG. 4 is a flowchart of a timing adjustment method according to an embodiment of the invention;

fig. 5 is a schematic diagram of inter-frequency handover according to a third embodiment of the present invention.

Detailed Description

The following further description of the present invention, in order to facilitate understanding of those skilled in the art, is provided in conjunction with the accompanying drawings and is not intended to limit the scope of the present invention.

As shown in fig. 2, the method for adjusting the timing of the baseband according to the embodiment of the present invention includes, in each adjustment period:

The method for obtaining the receiving timing sequence offset and the transmitting timing sequence offset of the baseband processing unit BBU and the receiving timing sequence offset and the transmitting timing sequence offset of the remote radio unit RRU includes one of the following: GPS detection, air interface synchronous detection and fine adjustment detection.

The method for obtaining the receiving timing sequence offset and the transmitting timing sequence offset of the baseband processing unit BBU and the receiving timing sequence offset and the transmitting timing sequence offset of the remote radio unit RRU comprises the following steps:

Wherein the content of the first and second substances,

The method for obtaining the data receiving adjustment amount and the data transmitting adjustment amount corresponding to the baseband processing comprises the following steps:

T_periindicating the time period when the cycle timing is fine-tuned.

As shown in fig. 2, the method for adjusting a timing of a radio frequency according to an embodiment of the present invention is characterized in that each adjustment period includes:

recovering the CPRI frame header;

As shown in fig. 2, the timing adjustment apparatus for baseband according to the embodiment of the present invention includes:

The method for the timing detection module to obtain the receiving timing offset and the transmitting timing offset of the baseband processing unit BBU and the receiving timing offset and the transmitting timing offset of the remote radio unit RRU includes one of the following: GPS detection, air interface synchronous detection and fine adjustment detection.

The timing detection module obtains the receiving timing sequence offset and the transmitting timing sequence offset of the baseband processing unit BBU and the receiving timing sequence offset and the transmitting timing sequence offset of the remote radio unit RRU, and comprises the following steps:

Of RRUReceive timing offset T_{rru_rx}＝T_{bbu_rx}-T_a3-T₁₂And a transmission timing offset T_{rru_tx}＝T_{bbu_rx}+T_2a-T₁₂；

Wherein the content of the first and second substances,

The time sequence calculation module obtains the data receiving adjustment amount and the data transmitting adjustment amount corresponding to the baseband processing, and comprises the following steps:

T′_{bbu_rx}Represents BBU T_periWhen the time sequence is finely adjusted periodically, the time sequence offset of a receiving link of the previous period is adjusted;

T_periindicating the time period when the cycle timing is fine-tuned.

As shown in fig. 2, the radio frequency timing adjustment apparatus according to the embodiment of the present invention includes:

a frame header recovery module, configured to recover the CPRI frame header;

Example one

The device of the embodiment of the invention is divided into a BBU side and an RRU side, and refer to fig. 2.

The BBU side portion includes:

c201, a time sequence detection module: the timing detection for completing the receiving and transmitting can include various modes, such as GPS, air interface synchronization, fine tuning detection algorithm and the like.

C202, a frame header generation module: after the power-on is finished, namely, a clock provided by a crystal oscillator is utilized to generate a fixed 10ms frame header as a CPRI frame header, and the frame header is kept unchanged.

C203, a time sequence calculation module: and calculating the true offset of the receiving and transmitting air interface frame header according to the CPRI frame header and the detection value output by the time sequence detection module. And the offset of the data reception and transmission corresponding to the baseband processing.

C204, a first time sequence adjusting module: and adjusting the receiving and transmitting frame headers processed by the baseband according to the offset output by the time sequence computing module, and adjusting the data stream of the baseband.

C205, CPRI first interface module: and the baseband time domain data which is received and transmitted, and is sent to the RRU through the control word, data or control channel of the CPRI according to the calculated receiving and transmitting offset corresponding to the radio frequency.

The RRU side part comprises:

c211, a CPRI second interface module: and receiving and transmitting the received and transmitted baseband time domain data, and receiving the receiving and transmitting offset corresponding to the radio frequency calculated by the BBU through the control word, data or control channel of the CPRI.

C212, frame header recovery module: and recovering the received 10ms frame header of the CPRI interface, checking, and recovering the CPRI frame header according to a CPRI data format by utilizing the hyper frame number in the CPRI protocol.

C213, a second timing adjustment module: and the time sequence adjusting module generates a receiving frame header and a transmitting frame header and a data frame header required in radio frequency processing on the basis of the CPRI recovery frame header according to the receiving offset and the transmitting offset issued by the BBU.

C214, a receiving and transmitting control module: the receiving and sending control can directly carry out switching operation on the LNA and the PA according to the receiving and sending frame head generated by the time sequence adjusting module and the protection time of the LNA and the PA.

Referring to fig. 3, a definition of timing names for an embodiment of the present invention is given.

T₁₂And the transmission delay introduced by CPRI of BBU and RRU is shown.

T_2aAnd the processing time delay from the time domain data of the CPRI port of the RRU to the radio frequency signal of the antenna port is represented.

T_a3And the processing time delay from the radio frequency signal of the antenna port of the RRU to the time domain data of the CPRI port is represented.

T_{bbu_rx_proc}Representing the physical layer processing time of the BBU receive link.

T_{bbu_tx_proc}Representing the physical layer processing time of the BBU transmit link.

T_{bbu_rx}And the offset from the CPRI time domain data frame header to the CPRI frame header of the receiving link of the BBU is represented.

T_{bbu_tx}And the offset from the CPRI time domain data frame header to the CPRI frame header of the transmission link of the BBU is represented.

T_{rru_rx}And the offset from the CPRI frame header of the RRU to the antenna port is shown.

T_{rru_tx}And the offset of the CPRI frame header of the RRU from the antenna port transmission is represented.

T_gpsAnd the offset of the CPRI frame header to the GPS air interface frame header is represented.

T_{adj_rx}Indicating the offset adjustment for the receive chain.

T_{adj_tx}Indicating the offset adjustment for the transmit chain.

T_periIndicating the time period when the cycle timing is fine-tuned.

T′_{bbu_rx}Represents BBU T_periAnd when the timing is finely adjusted in the period, the receiving link timing offset of the previous period.

T′_{bbu_tx}Representing BBUT_periAnd when the time sequence is finely adjusted in the period, the time sequence offset of the transmission link in the previous period is adjusted.

The timing offset calculation method of the embodiment of the invention is as follows, and is collectively called as A_{Time_Calc}：

Receive and transmit timing offset T of BBU_{bbu_rx}And T_{bbu_tx}，T_{bbu_tx}＝T_{bbu_rx}-T_2a-T_a3-TA；

Timing offset T of RRU_{rru_rx}＝T_{bbu_rx}-T_a3-T₁₂And T_{rru_tx}＝T_{bbu_rx}+T_2a-T₁₂；

BBU receiving service processing offset T_{bbu_rx}+T_{bbu_rx_proc}And transmit traffic initiation offset T_{bbu_tx}-T_{bbu_tx_proc}。

According to a time period T_periFine tuning the time sequence period, and receiving the current value T of the time sequence offset of the link_{bbu_rx}＝T′_{bbu_rx}+T_{rx_adj}Current value of transmit link timing offset, T_{bbu_tx}＝T′_{bbu_tx}+T_{tx_adj}。

As shown in fig. 4, the timing adjustment processing flow of the combination of the baseband and the radio frequency according to the embodiment of the present invention is as follows:

step S401: the BBU generates 10ms counting according to the crystal oscillator, and outputs 10ms pulse as CPRI frame header;

step S402: the initial timing detection method may be selected according to the device characteristics, and commonly used detection methods include: GPS synchronization, air interface synchronization and the like;

step S403: method A for calculating timing offset according to BBU_{Time_Calc}Calculating the timing sequence offset required by the BBU and the RRU, and sending the offset of the RRU to the RRU;

step S404: the BBU generates a CPRI data receiving and transmitting frame header according to the time sequence offset, and the baseband service processes the receiving and transmitting frame header;

step S405: and judging whether the time sequence is normal or not, wherein the method can be selected according to the equipment characteristics, if the time sequence is normal, the baseband service processing is started, and if the time sequence is not normal, the method jumps to 402 to detect the time sequence again.

Step S406: according to the frame header driving data generated in S404, the baseband processing flow can be in a completely pipelined state.

Step S407: in the normal baseband processing process, according to the time period T_periThe period timing detection can be performed by pilot frequency estimation, such as detecting timing error or timing adjustment command to obtain period adjustment value T_{adj_rx}And T_{adj_tx}。

Step S408: method A for calculating timing offset according to BBU_{Time_Calc}And the period adjustment amount T_{adj_rx}And T_{adj_tx}And calculating the time sequence adjustment amount after the period adjustment, and generating a data receiving and transmitting frame header. And sending the calculated timing sequence adjustment amount of the RRU to the RRU equipment.

Step S409: and judging whether the period time sequence adjustment amount is normal or not, wherein the judging method can be different according to the equipment characteristics, if the period time sequence adjustment amount is normal, the period time sequence adjustment is carried out, otherwise, the step is shifted to S407 to carry out period time sequence detection again.

Step S40 a: generating a CPRI data receiving and transmitting frame header according to the periodic timing offset, processing the receiving and transmitting frame header by the baseband service, and entering the baseband service processing S406.

Step S411: and the RRU recovers the CPRI frame header of the BBU.

Step S412: receiving timing sequence offset T issued by BBU_{rru_rx}And T_{rru_tx}。

Step S413: according to the CPRI frame header obtained in S411 and the timing sequence offset T obtained in S412_{rru_rx}And T_{rru_tx}And generating the transmission and reception frame frequency of the RRU.

Step S414: the RRU switches off the LNA and switches on the PA according to the generated transmitting and receiving frame frequency, and the TDD system needs to switch off the LNA and switch on the PA according to the frame frequency.

Step S415: and according to the frame header driving data generated in the step S413, processing such as spectrum shifting, interpolation, sampling, filtering and the like is performed, and the processing flow can be in a completely running state.

Example two:

for the base station device, due to locking the GPS clock, according to the PP1S signal of the GPS, the receiving and transmitting air interface clocks of the base station can be locked to the timing sequence of the GPS, and TA in fig. 3 is zero.

The embodiment of the invention has the same processing flow, but a part of the operation steps can be selected as the following specific methods:

step S402: the base station can lock the GPS clock, can synchronize according to PP1S of the GPS, and can calibrate the crystal oscillator according to the GPS clock.

Step S405: the timing condition may be determined based on the locked state of the GPS.

Step S407: the period timing detection can be performed based on the PP1S of the GPS, and if a timing deviation is detected, the S408 start period timing adjustment compensation can be performed.

Step S409: the timing condition may be determined based on the locked state of the GPS.

Example three:

for a terminal device or a Relay device including a terminal function, there is no GPS receiver, and reception is delayed and transmitted before a base station device, the receiving and transmitting of the terminal are separated by an air interface frame header, and the device mobility, so that the terminal device needs to maintain a timing sequence in time.

step S402: the terminal can perform air interface synchronization and synchronize to the base station network.

Step S403: in the initial timing calculation, downlink synchronization or receiving link timing is performed first, and uplink access is performed to obtain the transmission delay TA between the terminal and the base station.

Step S405: the demodulation performance of downlink and uplink and physical channels can be used as the judgment basis according to the physical layer processing result of the terminal. If demodulation is normal, timing adjustment can be considered normal, and if demodulation is abnormal, timing adjustment can be considered abnormal.

Step S407: the time offset of the physical link may be estimated based on the pilot, and if a timing offset is detected, S408 start cycle timing adjustment compensation may be performed.

Step S409: and the tolerable intersymbol interference threshold of the terminal equipment is used as the already-adjusted state of the periodic time sequence. And if the time sequence deviation is larger than the maximum value of the time sequence deviation of the intersymbol interference, the time sequence correction is considered to be abnormal, and if the time sequence deviation is smaller than the maximum value of the time sequence deviation, the time sequence correction is considered to be normal.

Example four:

for terminal equipment with special requirements, each stage of BBU and RRU physical layer processing can be timed according to the method of the embodiment of the invention, and the function strictly depending on the time sequence is realized according to the timing information.

For example, in a super cell, the distance between base stations is more than tens of KM, even hundreds of KM, and when signals of different base stations reach a terminal device, the time difference may even reach ms level. At this time, when the neighboring cell is measured, the terminal receives and processes the time domain signal of the pilot frequency neighboring cell in the process of the serving cell, and searches the downlink time sequence of the pilot frequency neighboring cell again according to the time. For LTE system, GAP measurement period is T_GAPThe primary and secondary synchronization periods are T_SYNIn addition to the RRU frequency point switching delay and the frequency point switching command transmission delay, it is necessary to ensure the acquisition of the pilot frequency time domain signal time T_Time≥T_SYN。

According to the time sequence adjusting method provided by the embodiment of the invention, the BBU and the RRU start operation at regular time to complete the pilot frequency measurement function of the super cell.

Referring to fig. 5, specific timing information is described. The embodiment of the invention has the same processing flow, but a part of the operation steps can be selected as the following specific methods:

step S406: and receiving the GAP measurement period sent by the MAC at the time T1 according to the subframe header timing time generated in S406, receiving the switching adjacent frequency point at the time T2, sending the switching adjacent frequency point to the RRU at the time T3, switching back to the receiving adjacent frequency point at the time T6, and sending the switching adjacent frequency point to the RRU at the time T7. In the period of T5, the downstream PHY has T_TimeAnd carrying out neighbor measurement on the pilot frequency data of the time.

Step S408: after the periodic timing sequence adjustment is carried out on the BBU, frame headers for receiving and transmitting are generated, a subframe header of a receiving link is generated at the same time, and a subframe number is maintained.

Step S413: after the RRU carries out time sequence adjustment, frame headers for receiving and transmitting are generated, a sub-frame header of a receiving link is generated at the same time, T4 of delta sms and T8 of delta ems behind the sub-frame header are generated at fixed time, and T8 time needs to be met_GAP-Δs-Δe≥T_SYN。

Step S415: when the radio frequency link is processed, the frequency point switching is carried out according to T4 and T8 moments generated by S413 so as to ensure T_GAPThe inner BBU can obtain T_Time＝T_GAPTime domain data of a neighborhood region of the time between minus delta s and delta e, and simultaneously, the service outside the GAP period is not influenced.

It should be noted that the above-mentioned embodiments are only for facilitating the understanding of those skilled in the art, and are not intended to limit the scope of the present invention, and any obvious substitutions, modifications, etc. made by those skilled in the art without departing from the inventive concept of the present invention are within the scope of the present invention.

Claims

1. A timing adjustment method of a baseband is characterized by comprising the following steps in each adjustment period:

2. The timing adjustment method according to claim 1, wherein the manner of obtaining the receive timing offset and the transmit timing offset of the BBU and the receive timing offset and the transmit timing offset of the RRU comprises one of: GPS detection, air interface synchronous detection and fine adjustment detection.

3. The timing adjustment method of claim 1, wherein obtaining a receiving timing offset and a transmitting timing offset of the baseband processing unit BBU and a receiving timing offset and a transmitting timing offset of the remote radio unit RRU comprises:

Wherein the content of the first and second substances,

4. The timing adjustment method of claim 3, wherein obtaining the adjustment amount of data reception and the adjustment amount of data transmission corresponding to the baseband processing comprises:

T_periindicating the time period when the cycle timing is fine-tuned.

5. A method for adjusting timing of a radio frequency, comprising, in each adjustment period:

receiving a Common Public Radio Interface (CPRI) frame header, a Radio Remote Unit (RRU) receiving timing sequence offset, a transmitting timing sequence offset, a data receiving adjustment amount and a data transmitting adjustment amount corresponding to baseband processing, and a baseband processing data stream after baseband processing unit (BBU) adjustment;

recovering the CPRI frame header;

6. A timing adjustment apparatus for a baseband, comprising:

7. The timing adjustment apparatus of claim 6,

8. The timing adjustment apparatus of claim 6, wherein the timing detection module obtains a receiving timing offset and a transmitting timing offset of the baseband processing unit BBU and a receiving timing offset and a transmitting timing offset of the remote radio unit RRU, and comprises:

Wherein the content of the first and second substances,

9. The timing adjustment apparatus of claim 8, wherein the timing calculation module obtains the adjustment amount of data reception and the adjustment amount of data transmission corresponding to the baseband processing, and comprises:

T_periindicating the time period when the cycle timing is fine-tuned.

10. An apparatus for adjusting timing of a radio frequency, comprising:

the second interface module is used for receiving a common public radio interface CPRI frame header, a radio remote unit RRU receiving time sequence offset, a transmitting time sequence offset, a data receiving adjustment amount and a data transmitting adjustment amount corresponding to baseband processing, and a baseband processing data stream after baseband processing unit BBU adjustment;

a frame header recovery module, configured to recover the CPRI frame header;