WO2016078401A1

WO2016078401A1 - Time sequence adjustment method and apparatus combining baseband and radio frequency

Info

Publication number: WO2016078401A1
Application number: PCT/CN2015/081569
Authority: WO
Inventors: 何勃; 张凯敏; 宋春辉
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-11-21
Filing date: 2015-06-16
Publication date: 2016-05-26
Also published as: CN105682214A; CN105682214B

Abstract

A time sequence adjustment method and apparatus combining a baseband and a radio frequency. Each adjustment cycle comprises: detecting a reception time sequence and a transmission time sequence of data, and acquiring a reception time sequence offset and a transmission time sequence offset of a baseband unit (BBU), and a reception time sequence offset and a transmission time sequence offset of a remote radio unit (RRU); generating a common public radio interface (CPRI) frame header, and acquiring an offset of an air interface frame header; acquiring a data reception adjustment amount and a data transmission adjustment amount corresponding to baseband processing according to the reception time sequence offset and the transmission time sequence offset of the BBU as well as the offset of the air interface frame header; adjusting a reception frame header and a transmission frame header of baseband processing, and adjusting a data flow of baseband processing; and outputting the CPRI frame header, the reception time sequence offset and the transmission time sequence offset of the RRU, the data reception adjustment amount and the data transmission adjustment amount, and the adjusted data flow.

Description

Timing adjustment method and device for baseband and radio frequency combination

Technical field

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

Background technique

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

The ground-to-air communication terminal in the related art, such as a CPE (Customer Premise Equipment), a Relay (Relay Node), a test terminal device, and the like, requires a special terminal-side device; for example, a terminal-side device of ground-to-air communication; CPE and Relay that implement backhaul and edge coverage; and terminal equipment dedicated to drive testing and testing.

Such terminal-side devices need to support functions such as high-power transmission, long-distance communication, special test functions, and special performance indicators. Therefore, such devices usually adopt the BBU and RRU separate design of the base station.

The terminal side device needs to ensure that the receiving and transmitting frame headers are separated and synchronized with the air interface on the base station side. And because of the high-speed movement of the terminal equipment, the crystal oscillator caused by the GPS and the base station are not synchronized, the receiving and transmitting frame headers have a large range of real-time drift.

In view of the above situation, the base station equipment of the BBU and the RRU separate structure needs to perform clock calibration and air interface timing adjustment according to GPS (Global Positioning System); the terminal side equipment needs BBU to perform data and timing adjustment in real time; TDD (Time) Division Duplexing, system RRU needs to perform receiving and transmitting switching according to timing; RRU needs to perform power statistics and standing wave ratio detection according to timing.

As shown in Figure 1, the common BBU and RRU timing adjustment processing flow includes three parts, namely the frame header adjustment, the receiving process, and the transmitting process.

The frame header adjustment processing process includes:

Step S101: GPS signal search, after the GPS is locked, the PP1S is restored according to the GPS (Pulse per 1 second, one pulse per second) for clock phase discrimination, and an accurate 10 MHz clock can be obtained after clock phase discrimination;

Step S102: The BBU generates a 10 ms signal according to the calibrated 10 MHz clock, and generates a 10 ms signal of the air interface according to the PP1S signal of the GPS. According to the baseband and radio frequency processing delay, a 10 ms signal is generated for use as a CPRI (Common Public Radio Interface) frame header;

The launch process includes:

Step S103: The BBU upper layer starts service scheduling, and the baseband system is scheduled to start a business process;

Step S104: The baseband system performs baseband processing according to the high layer scheduling, and performs bit level and symbol level processing respectively, and then performs signal processing in the frequency domain and the time domain;

Step S105: After the baseband processing is completed, the time domain data needs to be buffered, and the data of the service scheduling is aligned with the transmitted CPRI frame header, and the data is sent to the RRU according to the frame header of the CPRI through the CPRI interface;

Step S106: The CPRI receiving side of the RRU needs to restore the frame header of the CPRI, and perform baseband time domain data reception according to the CPRI frame header.

Step S107: The received baseband time domain data needs to be buffered, and the intermediate frequency processing start time is calculated according to different bandwidths, processing delays, and the like;

Step S108: The intermediate frequency link processes the baseband data, and after several stages of interpolation and filtering and spectrum shifting, the intermediate frequency digital signal is obtained;

Step S109: the intermediate frequency digital signal is processed by a radio frequency circuit such as a DAC (Digital to Analog Converter) to generate a radio frequency analog signal. At this time, the data is aligned to the air interface frame recovered by the GPS, and the radio frequency signal is sent out. The TDD system needs to turn off the LNA (Low Noise Amplifier) to turn on the PA (Power Amplifier) operation according to the air interface timing;

The receiving process includes:

Step S110: The RRU receives the analog signal according to the air interface frame header recovered by the GPS, and the TDD system needs to turn off the low noise amplifier LNA to open the PA operation according to the air interface timing. After that, the RF signal is converted by an RF link and digital/analog AD to obtain an intermediate frequency digital signal;

Step S111: After the radio frequency link performs spectrum shifting, sampling, filtering, etc., the radio frequency number is Signal processing is baseband time domain data;

Step S112: The time domain data needs to be cached, and waits for the CPRI frame header time;

Step S113: After the CPRI frame header arrives, the RRU reads the time domain data, and sends the time domain data to the BBU through the CPRI interface.

Step S114: The BBU performs a fetch operation according to the CPRI frame header to obtain time domain data aligned with the air interface.

Step S115: The time domain data needs to be processed in the time domain and the frequency domain, and processed by the symbol level and the bit level to obtain the service data of the baseband;

Step S116: After the baseband processing is completed, the service data is reported to the upper layer.

The related art method requires a relatively complicated air interface and CPRI frame header adjustment method for the base station side device, and requires a large number of data buffer components.

For the terminal-side device, there is no GPS for clock calibration, and the crystal offset between the terminal and the base station will cause the frame header to drift; there is no GPS to perform timing synchronization of the PP1S, and the terminal side needs to perform air interface synchronization according to the protocol. The accuracy will drift; the terminal side matches the base station side timing, there will be delayed reception and early transmission, so the received and transmitted frame headers are different; there is no fixed relationship between the air interface and the CPRI frame header, the CPRI frame header is fixed, and the air interface header is fixed. Drift; positional movement of the terminal device, resulting in advance and lag drift of the receive and transmit headers.

Summary of the invention

This paper proposes a timing adjustment method and device for baseband and radio frequency combination, which can maintain the movement and crystal frequency offset of the terminal in real time.

A baseband timing adjustment method includes, in each adjustment period:

Detecting a reception timing and a transmission timing of the data, obtaining a reception timing offset of the baseband processing unit BBU, a transmission timing offset, and a radio frequency remote unit RRU receiving timing offset, and a transmission timing offset;

Generating a common radio interface CPRI frame header to obtain an offset of the air interface frame header;

According to the receiving timing offset of the BBU, the transmission timing offset, and the offset of the air interface frame header The amount of data reception adjustment corresponding to the baseband processing and the adjustment amount of the data transmission are obtained;

Adjusting the received frame header and the transmit frame header of the baseband processing, and adjusting the data stream processed by the baseband;

And outputting the CPRI frame header, the RRU reception timing offset, the transmission timing offset, the data reception adjustment amount, and the adjustment amount of the data transmission, and the adjusted data stream.

Optionally, the manner of obtaining the receiving timing offset, the transmitting timing offset, and the radio remote unit RRU receiving the timing offset and the transmitting timing offset of the baseband processing unit BBU includes one of the following: GPS detection, air interface synchronization Detection, fine-tuning detection.

Optionally, obtaining the receiving timing offset, the transmitting timing offset, and the radio remote unit RRU receiving timing offset and the transmitting timing offset of the baseband processing unit BBU, including:

The receiving timing offset T _{bbu_rx} and the transmitting timing offset T _{bbu_tx of the BBU are} expressed as T _{bbu_tx} =T _{bbu_rx} -T _2a -T _a3 -TA;

The RRU reception timing offset T _{rru_rx} = T _{bbu_rx -} T _{a3 -} T ₁₂ and the transmission timing offset T _{rru_tx} = T _{bbu_rx} + T _{2a -} T ₁₂ ;

among them,

T ₁₂ represents the transmission delay introduced by the CPRI of the BBU and the RRU;

T _2a represents the processing delay of the RPR CPRI port time domain data to the antenna port radio frequency signal;

T _a3 represents the processing delay of the RF signal of the RRU antenna port to the CPRI port time domain data;

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

Optionally, obtaining a data receiving adjustment amount corresponding to the baseband processing and an adjustment amount of the data transmission, including:

Corresponding to the received baseband data and an adjustment amount of data transmission _T rx_adj _T tx_adj adjustment amount is expressed _{_{as: T bbu_rx = T 'bbu_rx +}} T rx_adj; T bbu_tx = T' bbu_tx + T tx_adj;

T' _{bbu_rx} indicates the receiving link timing offset of the previous period when the BBU T _peri period fine-tuning timing;

T' _{bbu_tx} indicates the transmission link timing offset of the previous period when the BBU T _peri period fine-tuning timing;

T _peri represents the time period when the periodic timing is fine-tuned.

A radio frequency timing adjustment method includes, in each adjustment period:

Receiving a common radio interface CPRI frame header, a radio remote unit RRU receiving a timing offset, a transmission timing offset, a data reception adjustment amount, and an adjustment amount of data transmission, and a data stream;

Recovering the CPRI frame header;

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

The processed intermediate frequency or zero intermediate frequency data is output.

A timing adjustment device for a baseband, comprising:

The timing detection module is configured to: detect a reception timing and a transmission timing of the data, obtain a reception timing offset of the baseband processing unit BBU, a transmission timing offset, and a radio frequency remote unit RRU reception timing offset, and a transmission timing offset ;

Frame header generation module: set to: generate a common radio interface CPRI frame header;

The timing calculation module is configured to: obtain an offset of the air interface frame header, and obtain a data reception adjustment amount corresponding to the baseband processing according to the reception timing offset of the BBU, the transmission timing offset, and the offset of the air interface frame header And the amount of adjustment of the data transmission;

The first timing adjustment module is configured to: adjust a received frame header and a transmit frame header of the baseband processing, and adjust a data stream processed by the baseband;

The first interface module is configured to: output the CPRI frame header, the RRU reception timing offset, the transmission timing offset, the data reception adjustment amount, and the adjustment amount of the data transmission, and the adjusted data stream.

Optionally, the manner in which the timing detection module obtains the reception timing offset, the transmission timing offset, and the radio remote unit RRU reception timing offset and the transmission timing offset of the baseband processing unit BBU includes one of the following: GPS detection , air interface synchronization detection, fine-tuning detection.

Optionally, the timing detection module obtains a receive timing offset, a transmit timing offset, and a radio remote unit RRU receive timing offset, and a transmit timing offset of the baseband processing unit BBU, including:

The reception timing offset T _{bbu_rx} and the transmission timing offset T _{bbu_tx of the BBU are} expressed as T _{bbu_tx} =T _{bbu_rx} -T _2a -T _a3 -TA;;

RRU reception timing offset T _{rru_rx} = T _{bbu_rx -} T _{a3 -} T ₁₂ and emission timing offset T _{rru_tx} = T _{bbu_rx} + T _{2a -} T ₁₂ ;

among them,

Optionally, the timing calculation module obtains the data reception adjustment amount corresponding to the baseband processing and the adjustment amount of the data transmission, including:

T _peri represents the time period when the periodic timing is fine-tuned.

A radio frequency timing adjustment device includes:

The second interface module is configured to: receive a common radio interface CPRI frame header, a radio remote unit RRU receiving timing offset, a transmission timing offset, a data receiving adjustment amount, and an adjustment amount of data transmission, and a data stream;

a frame header recovery module, configured to: restore the CPRI frame header;

The second timing adjustment module is configured to: according to the RRU receiving timing offset and the transmission timing offset, generate a receiving frame header and a transmitting frame header, and a radio frequency processed data frame header based on the CPRI recovery frame header ;

The transceiver control module is configured to: control the RF antenna switch, and output the processed intermediate frequency or zero intermediate frequency data.

A computer readable storage medium storing computer executable instructions for performing the method of any of the above.

Compared with related technologies, the apparatus and method of the present invention can simplify the data and timing processing flow of the base station equipment, perform the processing start time according to the timing, and the data processing reaches the pipeline processing, reducing the BBU. And RRU data storage operations, thereby reducing equipment complexity and cost. It can flexibly adjust the frame header of the terminal device, maintain the movement of the terminal and the crystal frequency offset in real time, and is suitable for the transmission and reception header separation characteristics of the terminal, and better adapt to the radio frequency processing functions such as the terminal inter-frequency switching timing.

BRIEF abstract

1 is a timing adjustment method in the related art;

2 is a baseband and radio frequency combined timing adjustment apparatus according to an embodiment of the present invention;

3 is a timing diagram of a timing adjustment method according to an embodiment of the present invention;

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

FIG. 5 is a schematic diagram of inter-frequency switching according to Embodiment 3 of the present invention.

Embodiments of the invention

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 2, the timing adjustment method of the baseband provided by the embodiment of the present invention includes:

Obtaining a data reception adjustment amount corresponding to the baseband processing and an adjustment amount of the data transmission according to the reception timing offset amount, the transmission timing offset amount, and the offset of the air interface frame header of the BBU;

The manner of obtaining the reception timing offset, the transmission timing offset, and the radio remote unit RRU receiving timing offset and the transmission timing offset of the baseband processing unit BBU includes one of the following: GPS detection, Air interface synchronization detection, fine-tuning detection.

Obtaining a reception timing offset, a transmission timing offset, and a radio remote unit RRU receiving timing offset and a transmission timing offset of the baseband processing unit BBU, including:

among them,

Obtaining the data reception adjustment amount corresponding to the baseband processing and the adjustment amount of the data transmission, including:

T _peri represents the time period when the periodic timing is fine-tuned.

As shown in FIG. 2, the radio frequency timing adjustment method provided by the embodiment of the present invention includes:

Recovering the CPRI frame header;

As shown in FIG. 2, the timing adjustment apparatus of the baseband provided by the embodiment of the present invention includes:

The manner in which the timing detection module obtains the reception timing offset, the transmission timing offset, and the radio remote unit RRU reception timing offset and the transmission timing offset of the baseband processing unit BBU includes one of the following: GPS detection, air interface synchronization detection , fine-tuning detection.

The timing detection module obtains a reception timing offset, a transmission timing offset, and a radio remote unit RRU reception timing offset and a transmission timing offset of the baseband processing unit BBU, including:

among them,

The timing calculation module obtains the data reception adjustment amount corresponding to the baseband processing and the adjustment amount of the data transmission, including:

T _peri represents the time period when the periodic timing is fine-tuned.

As shown in FIG. 2, the radio frequency timing adjustment apparatus provided by the embodiment of the present invention includes:

a frame header recovery module, configured to: restore the CPRI frame header;

Embodiment 1

The device in the embodiment of the present invention is divided into two parts, a BBU side and an RRU side, with reference to FIG. 2 .

The BBU side part includes:

C201, timing detection module: complete the timing detection of receiving and transmitting, which can include multiple modes, GPS, air interface synchronization, fine-tuning detection algorithm, and the like.

C202. Frame header generation module: After the power is turned on, the clock provided by the crystal oscillator is used to generate a fixed 10 ms frame header, which is used as a CPRI frame header and remains unchanged.

C203. Timing calculation module: Calculate the offset of the real receiving and transmitting air interface frame header according to the CPRI frame header and the detection value output by the timing detection module. And the offset of the data reception and transmission corresponding to the baseband processing.

C204. The first timing adjustment module: adjusts the receiving and transmitting frame headers of the baseband processing according to the offset output by the timing calculation module, and adjusts the data stream of the baseband.

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

The RRU side part includes:

C211, CPRI second interface module: completes the receiving and transmitting baseband time domain data transceiving, and receives the receiving and transmitting offset corresponding to the radio frequency calculated by the BBU through the CPRI control word, data or control channel.

C212. The frame header recovery module: restores the received 10 ms frame header of the CPRI interface, and performs verification, and uses the superframe number in the CPRI protocol to recover the CPRI frame header according to the CPRI data format.

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

C214, transceiver control module: transceiver control can directly switch to the LNA and PA according to the transmission and reception header generated by the timing adjustment module, plus the protection time of the LNA and PA.

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

T ₁₂ represents the transmission delay introduced by the CPRI of the BBU and the RRU.

T _2a represents the processing delay of the RPR's CPRI port time domain data to the antenna port RF signal.

T _a3 represents the processing delay of the RF signal of the antenna port of the RRU to the time domain data of the CPRI port.

T _{bbu_rx_proc} represents the physical layer processing time of the BBU receiving link.

T _{bbu_tx_proc} represents the physical layer processing time of the BBU transmit link.

T _{bbu_rx} represents the offset of the _BRU 's receive link CPRI time domain data frame header to the CPRI frame header.

T _{bbu_tx} represents the offset of the _BRU 's transmit link CPRI time domain data frame header to the CPRI frame header.

T _{rru_rx} represents the offset of the RRU's CPRI frame header to the antenna port.

T _{rru_tx} represents the offset of the RRU's CPRI frame header to the antenna port.

T _gps represents the offset from the CPRI frame header to the GPS air interface frame header.

T _{adj_rx} represents the offset adjustment amount of the receiving link.

T _{adj_tx} represents the offset adjustment amount of the transmission link.

T _peri represents the time period when the periodic timing is fine-tuned.

T' _{bbu_rx} indicates the receive link timing offset of the previous cycle when the BBU T _peri period fine-tunes the timing.

T' _{bbu_tx} indicates the transmit link timing offset of the previous cycle when the BBU T _peri period fine-tunes the timing.

The timing offset calculation method of the embodiment of the present invention is as follows, and the calculation method is collectively referred to as A _{Time_Calc} :

Receive and transmit timing offsets of the BBU T _{bbu_rx} and T _{bbu_tx} , T _{bbu_tx} =T _{bbu_rx} -T _2a -T _a3 -TA;

The timing offset of the RRU is T _{rru_rx} = T _{bbu_rx -} T _{a3 -} T ₁₂ and T _{rru_tx} = T _{bbu_rx} + T _{2a -} T ₁₂ ;

The BBU receives the service processing offset T _{bbu_rx} + T _{bbu_rx_proc} and the transmit service start offset T _{bbu_tx} -T _{bbu_tx_proc} .

The timing period fine adjustment is performed according to the time period T _peri , the reception link timing offset current value T _{bbu — rx} = T′ _{bbu — rx} + T _{rx — adj} , and the transmission link timing offset current value T _{bbu — tx} = T′ _{bbu — tx} + T _{tx — adj} .

As shown in FIG. 4, the timing adjustment process of the baseband and radio frequency combination in the embodiment of the present invention is as follows:

Step S401: The BBU generates a 10 ms count according to the crystal oscillator, and outputs a 10 ms pulse as a CPRI frame header;

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

Step S403: Calculate the timing offset required by the BBU and the RRU according to the BBU timing offset calculation method A _{Time_Calc} , and send the offset of the RRU to the RRU;

Step S404: The BBU generates a CPRI data receiving and transmitting frame header according to the timing offset, and the baseband service processes the receiving and transmitting frame headers.

Step S405: determining whether the timing is normal may be selected according to device characteristics, such as normal, starting baseband service processing, otherwise jumping to 402 re-detecting timing.

Step S406: According to the frame header driving data generated by S404, the baseband processing flow can be completely watered.

Step S407: During the normal baseband processing, the periodic timing detection is performed according to the time period T _peri , and the detection method may be a method such as pilot estimation, such as detecting a timing error or a timing adjustment command, and obtaining periodic adjustment amounts T _{adj — rx} and T _{adj — tx} .

Step S408: Calculate the timing adjustment amount after the period adjustment according to the BBU timing offset calculation method A _{Time_Calc} and the period adjustment amounts T _{adj_rx} and T _{adj_tx} , and generate a data reception and transmission frame header. The calculated timing adjustment of the RRU is sent to the RRU device.

Step S409: determining whether the periodic timing adjustment amount is normal, and the determining method may be different according to device characteristics. If normal, the periodic timing adjustment is performed, otherwise, the jump to S407 re-period timing detection is performed.

Step S40a: The CPRI data receiving and transmitting frame header is generated according to the periodic timing offset, and the baseband service processes the receiving and transmitting frame header, and enters the baseband service processing S407.

Step S411: The RRU restores the CPRI frame header of the BBU.

Step S412: Receive timing offsets T _{rru_rx} and _{Trru_tx delivered by the BBU} .

Step S413: Generate a transmit and receive frame rate of the RRU according to the CPRI frame header acquired in S410 and the timing offsets T _{rru_rx} and _{Trru_tx} acquired by S411.

Step S414: The RRU needs to turn off the low-noise LNA to turn on the PA operation according to the frame rate according to the generated transmission and reception frame rate.

Step S415: performing spectrum shifting, interpolation, sampling, filtering, and the like according to the frame header driving data generated in S413, and the processing flow can be completely water-flowed.

Embodiment 2:

For the base station equipment, due to the GPS clock lock, the receiving and transmitting air interface clocks of the base station can be locked to the GPS timing according to the PP1S signal of the GPS, and the TA in FIG. 3 is zero.

The processing flow of the embodiment of the present invention is unchanged, but the method selectable for some operation steps is as follows:

Step S402: The base station can lock the GPS clock, and can synchronize according to the PP1S of the GPS, and can calibrate the crystal according to the same.

Step S405: The timing condition can be determined according to the locked state of the GPS.

Step S407: The timing detection of the cycle may be performed according to the PP1S of the GPS. If the timing deviation is detected, the S408 startup cycle timing adjustment compensation may be performed.

Step S409: The timing condition can be determined according to the locked state of the GPS.

Embodiment 3:

For the terminal device, or the terminal device including the terminal function, there is no GPS receiver, and the receiving stagnation, the transmission is ahead of the base station device, the terminal receiving and transmitting the air interface frame header is separated, and the device mobility, so that the terminal device needs timely maintenance timing.

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 a transmission delay TA of the terminal and the base station.

Step S405: According to the physical layer processing result of the terminal, the following line and uplink and physical channel demodulation performance are used as a judgment basis. If the demodulation is normal, the timing adjustment is considered normal, and if the demodulation is abnormal, the timing adjustment is considered abnormal.

Step S407: The time offset of the physical link may be estimated according to the pilot. If the timing offset is detected, the S408 startup cycle timing adjustment compensation may be performed.

Step S409: An inter-symbol interference threshold that can be tolerated by the terminal device as the periodic timing adjustment state. If the timing deviation is greater than the maximum value of the timing, it is considered normal.

Embodiment 4:

For a terminal device with special requirements, each stage of the BBU and RRU physical layer processing may be timed according to the method of the embodiment of the present invention, and the timing-dependent function is implemented according to the timing information.

For example, in a super cell, the distance between base stations is greater than several tens of KM, or even several hundred KM, and when the signals of different base stations reach the terminal device, the time difference can even reach the ms level. At the time of the neighboring cell measurement, the terminal receives and processes the time domain signal of the inter-frequency neighboring cell in the serving cell process, and searches for the downlink timing of the inter-frequency neighboring cell according to the second. For the LTE system, the GAP (interval) measurement period is T _GAP , the primary and secondary synchronization period is T _SYN , and the RRU frequency switching delay and the frequency point switching command transmission delay are required to ensure the acquisition of the inter-frequency time domain signal time T _{Time .} ≥T _SYN .

According to the timing adjustment method of the embodiment of the present invention, the BBU and the RRU start the operation periodically, and complete the super The inter-frequency measurement function of the class cell.

The timing information will be described with reference to FIG. 5. The processing flow of the embodiment of the present invention is unchanged, but the method selectable for some operation steps is as follows:

Step S406: Receive the GAP measurement period sent by the MAC (Media Access Control) at the time T1, and receive the handover neighbor frequency at the time T2 according to the subframe start timing generated by S406. The RRU is sent back to the receiving neighbor frequency point at time T6, and sent to the RRU at time T7. During the T5 time period, the downlink PHY (physical layer) is the inter-frequency measurement with the inter-frequency data of the T _Time .

Step S408: After the BBU performs periodic timing adjustment, generates a frame header for receiving and transmitting, simultaneously generates a subframe header of the receiving link, and maintains the subframe number.

Step S413: After the RRU performs timing adjustment, generates a frame header for receiving and transmitting, and generates a subframe header of the receiving link, and generates T4 of Δsms and T8 of Δems after the timing of the subframe header, where T needs to be satisfied. _{GAP -} Δs - Δe ≥ T _SYN .

Step S413: During radio frequency link processing, according to the T4 and T8 times generated by S413, frequency point switching is performed to ensure that the BBU in the T _GAP can obtain the neighbor time domain data of T _Time = T _{GAP -} Δs - Δe time, and at the same time Affects services outside the GAP cycle.

One of ordinary skill in the art will appreciate that all or a portion of the steps of the above-described embodiments can be implemented using a computer program flow, which can be stored in a computer readable storage medium, such as on a corresponding hardware platform (eg, The system, device, device, device, etc. are executed, and when executed, include one or a combination of the steps of the method embodiments.

Alternatively, all or part of the steps of the above embodiments may also be implemented by using an integrated circuit. These steps may be separately fabricated into individual integrated circuit modules, or multiple modules or steps may be fabricated into a single integrated circuit module. achieve.

The devices/function modules/functional units in the above embodiments may be implemented by a general-purpose computing device, which may be centralized on a single computing device or distributed over a network of multiple computing devices.

When the device/function module/functional unit in the above embodiment is implemented in the form of a software function module and sold or used as a stand-alone product, it can be stored in a computer readable storage medium. The above mentioned computer readable storage medium may be a read only memory, a magnetic disk or an optical disk or the like.

Industrial applicability

The embodiment of the invention can simplify the data processing and sequence processing of the base station device, perform the processing start time according to the sequence, the data processing reaches the pipeline processing, and reduce the data storage operation of the BBU and the RRU, thereby reducing the device complexity and cost. It can flexibly adjust the frame header of the terminal device, maintain the movement of the terminal and the crystal frequency offset in real time, and is suitable for the transmission and reception header separation characteristics of the terminal, and better adapt to the radio frequency processing functions such as the terminal inter-frequency switching timing.

Claims

A baseband timing adjustment method includes, in each adjustment period:

Detecting a reception timing and a transmission timing of the data, obtaining a reception timing offset of the baseband processing unit BBU, a transmission timing offset, and a radio frequency remote unit RRU receiving timing offset, and a transmission timing offset;

Generating a common radio interface CPRI frame header to obtain an offset of the air interface frame header;

Obtaining a data reception adjustment amount corresponding to the baseband processing and an adjustment amount of the data transmission according to the reception timing offset amount, the transmission timing offset amount, and the offset of the air interface frame header of the BBU;

Adjusting the received frame header and the transmit frame header of the baseband processing, and adjusting the data stream processed by the baseband;

And outputting the CPRI frame header, the RRU reception timing offset, the transmission timing offset, the data reception adjustment amount, and the adjustment amount of the data transmission, and the adjusted data stream.
The timing adjustment method according to claim 1, wherein the manner of obtaining the reception timing offset amount, the transmission timing offset amount, and the radio remote unit RRU reception timing offset amount, the transmission timing offset amount of the baseband processing unit BBU includes One of the following: GPS detection, air interface synchronization detection, fine-tuning detection.
The timing adjustment method according to claim 1, wherein the obtaining the reception timing offset, the transmission timing offset, and the radio remote unit RRU reception timing offset and the transmission timing offset of the baseband processing unit BBU include:

The receiving timing offset T bbu_rx and the transmitting timing offset T bbu_tx of the BBU are expressed as T bbu_tx =T bbu_rx -T 2a -T a3 -TA;

The RRU reception timing offset T rru_rx = T bbu_rx - T a3 - T 12 and the transmission timing offset T rru_tx = T bbu_rx + T 2a - T 12 ;

among them,

T 12 represents the transmission delay introduced by the CPRI of the BBU and the RRU;

T 2a represents the processing delay of the RPR CPRI port time domain data to the antenna port radio frequency signal;

T a3 represents the processing delay of the RF signal of the RRU antenna port to the CPRI port time domain data;

TA indicates the round-trip air interface delay from the base station to the terminal.
The timing adjustment method according to claim 3, wherein the data reception adjustment amount corresponding to the baseband processing and the adjustment amount of the data transmission are obtained, including:

Corresponding to the received baseband data and an adjustment amount of data transmission T rx_adj T tx_adj adjustment amount is expressed as: T bbu_rx = T 'bbu_rx + T rx_adj; T bbu_tx = T' bbu_tx + T tx_adj;

T' bbu_rx indicates the receiving link timing offset of the previous period when the BBU T peri period fine-tuning timing;

T' bbu_tx indicates the transmission link timing offset of the previous period when the BBU T peri period fine-tuning timing;

T peri represents the time period when the periodic timing is fine-tuned.
A radio frequency timing adjustment method includes, in each adjustment period:

Receiving a common radio interface CPRI frame header, a radio remote unit RRU receiving a timing offset, a transmission timing offset, a data reception adjustment amount, and an adjustment amount of data transmission, and a data stream;

Recovering the CPRI frame header;

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

The processed intermediate frequency or zero intermediate frequency data is output.
A timing adjustment device for a baseband, comprising:

The timing detection module is configured to: detect a reception timing and a transmission timing of the data, obtain a reception timing offset of the baseband processing unit BBU, a transmission timing offset, and a radio frequency remote unit RRU reception timing offset, and a transmission timing offset ;

Frame header generation module: set to: generate a common radio interface CPRI frame header;

The timing calculation module is configured to: obtain an offset of the air interface frame header, and obtain a data reception adjustment amount corresponding to the baseband processing according to the reception timing offset of the BBU, the transmission timing offset, and the offset of the air interface frame header And the amount of adjustment of the data transmission;

The first timing adjustment module is configured to: adjust a received frame header and a transmit frame header of the baseband processing, and adjust a data stream processed by the baseband;

The first interface module is configured to: output the CPRI frame header, the RRU reception timing offset, the transmission timing offset, the data reception adjustment amount, and the adjustment amount of the data transmission, and the adjusted data stream.
The timing adjustment device according to claim 6, wherein

The manner in which the timing detection module obtains the reception timing offset, the transmission timing offset, and the radio remote unit RRU reception timing offset and the transmission timing offset of the baseband processing unit BBU includes one of the following: GPS detection, air interface synchronization detection , fine-tuning detection.
The timing adjustment apparatus according to claim 6, wherein the timing detection module obtains a reception timing offset amount, a transmission timing offset amount, and a radio remote unit RRU reception timing offset amount, and a transmission timing offset amount of the baseband processing unit BBU ,include:

The reception timing offset T bbu_rx and the transmission timing offset T bbu_tx of the BBU are expressed as T bbu_tx =T bbu_rx -T 2a -T a3 -TA;;

The RRU reception timing offset T rru_rx = T bbu_rx - T a3 - T 12 and the transmission timing offset T rru_tx = T bbu_rx + T 2a - T 12 ;

among them,

T 12 represents the transmission delay introduced by the CPRI of the BBU and the RRU;

T 2a represents the processing delay of the RPR CPRI port time domain data to the antenna port radio frequency signal;

T a3 represents the processing delay of the RF signal of the RRU antenna port to the CPRI port time domain data;

TA indicates the round-trip air interface delay from the base station to the terminal.
The timing adjustment apparatus according to claim 8, wherein the timing calculation module obtains the data reception adjustment amount corresponding to the baseband processing and the adjustment amount of the data transmission, including:

Corresponding to the received baseband data and an adjustment amount of data transmission T rx_adj T tx_adj adjustment amount is expressed as: T bbu_rx = T 'bbu_rx + T rx_adj; T bbu_tx = T' bbu_tx + T tx_adj;

T' bbu_rx indicates the receiving link timing offset of the previous period when the BBU T peri period fine-tuning timing;

T' bbu_tx indicates the transmission link timing offset of the previous period when the BBU T peri period fine-tuning timing;

T peri represents the time period when the periodic timing is fine-tuned.
A radio frequency timing adjustment device includes:

The second interface module is configured to: receive a common radio interface CPRI frame header, a radio remote unit RRU receiving timing offset, a transmission timing offset, a data receiving adjustment amount, and an adjustment amount of data transmission, and a data stream;

a frame header recovery module, configured to: restore the CPRI frame header;

The second timing adjustment module is configured to: according to the RRU receiving timing offset and the transmission timing offset, generate a receiving frame header and a transmitting frame header, and a radio frequency processed data frame header based on the CPRI recovery frame header ;

The transceiver control module is configured to: control the RF antenna switch, and output the processed intermediate frequency or zero intermediate frequency data.
A computer readable storage medium storing computer executable instructions for performing the method of any of claims 1-5.