WO2013037213A1

WO2013037213A1 - Method and apparatus for power calibration

Info

Publication number: WO2013037213A1
Application number: PCT/CN2012/075377
Authority: WO
Inventors: 闫浩; 唐肖剑
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-09-15
Filing date: 2012-05-11
Publication date: 2013-03-21
Also published as: CN103002553A

Abstract

Disclosed in the present invention are a method and an apparatus for power calibration. The method comprises the following steps: a radio remote unit filling pseudo pilot on sub-carriers of the channels which don't have any main carrier; the radio remote unit using the pseudo pilot for power calibration. The present invention solves the problem of the failure of the power calibration on the channels which don't have any main carrier in related art, thereby achieving the effect of calibration on the channels which don't have any main carrier.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a power calibration method and apparatus. BACKGROUND OF THE INVENTION Currently, Time Division-Synchronous Code Division Multiple (Time Division-Synchronous Code Division Multiple)

Access, abbreviated as TD-SCDMA) The supported frequency bands are 1880mhz~1920mhz (F-band), 2010mhz~2025mhz (A-band), and 2300mhz~2400mhz (E-band). If it is necessary to establish a cross-band cell to increase the user capacity of the cell, then a Remote RF Unit (RRU) can transmit the RF signal across the frequency band. However, cross-spectrum power amplifiers are expensive to manufacture, and gain uniformity over a wide spectrum is difficult to guarantee. Therefore, the two signals are separately used for up-conversion and mixing, and finally, after the cavity filter is combined, transmitting from one antenna becomes the primary method for the RRU to realize multi-band RF signal output. In the TD-SCDMA system, the RRU shoulders the task of digitally upconverting and mixing the baseband signal into a radio frequency signal. The stability of the radio frequency signal determines the stability of the coverage of the entire cell. For user equipment (User Equipment, UE for short) Access plays a decisive role. The power calibration module of the RRU system software is mainly responsible for ensuring the stability of the RRU output power. At present, the power control of the RRU is generally implemented by feedback closed-loop power control. The implementation methods include: 1. The microwave detection tube directly performs closed-loop control in the RF part; 2. The digital attenuation of the transmission channel by software after analog-to-digital conversion The device is adjusted to ensure that the power of the transmitting port is stable. As can be seen from the TD-SCDMA protocol, the downlink pilot time slot is stable in baseband power because it transmits the SYNC_DL (downlink synchronization code) sequence at all times. In the related art, the stability of the downlink pilot slot power can be utilized to perform closed-loop power control on the primary carrier, thereby achieving the purpose of stabilizing the RF signal power of the antenna interface. A cross-band cell refers to establishing multiple sectors under one cell and establishing corresponding carrier groups under multiple sectors. Since there is only one primary carrier in one cell and the SYNC_DL sequence is only transmitted on the primary carrier, there is only one SYNC_DL sequence in one cell. When a cell is carried through multiple sets of channels (or multiple single-channel RRUs), one or more of the channels without the primary carrier will not be able to perform power calibration. A cross-band cell is implemented, that is, a multi-carrier cell is established on two (or more) different frequency bands. The primary carrier exists in one of the frequency bands, and only the secondary carrier is established on the other frequency bands to expand the bearer service. In a TD-SCDMA system, a cell has only one primary carrier. If the primary carrier is established on the F-band RRU, the R-band of the A-band does not have a primary carrier, but only the secondary carrier. As shown in Fig. 1, a schematic diagram of a channel carrying structure in the related art is shown. According to the power calibration scheme in the related art, since there is no primary carrier on some RRUs, the RRU cannot implement power calibration. In addition, since there is no downlink pilot power on the RRU, the digital pre-distortion (DPD) is also affected, and the output antenna port power is affected. Also, even if the DPD is not considered, the channel state cannot be determined because the detection channel power standing wave ratio cannot be detected. SUMMARY OF THE INVENTION The present invention provides a power calibration scheme to address at least the problem of power calibration in a related art that cannot be used for a channel without a primary carrier. According to an aspect of the present invention, a power calibration method is provided, including: a radio remote unit filling a pseudo pilot on a secondary carrier-free channel with a pseudo pilot; and the radio remote unit using the pseudo pilot for power calibration. Preferably, the radio remote unit fills the secondary carrier on the secondary carrier-free channel with the pseudo pilot. The radio remote unit fills the pilot time slot of the first secondary carrier on the channel without the primary carrier. frequency. Preferably, before the radio remote unit fills the secondary carrier on the secondary carrier-free channel, the method further includes: the radio remote unit receiving the cell identifier sent by the baseband pool unit; the radio remote unit according to the cell identifier Generate a pseudo pilot. Preferably, after the radio remote unit is filled with the pseudo pilot on the secondary carrier on the channel without the primary carrier, the method further includes: the radio remote unit filling data on one time slot of the secondary carrier; The time slot serves as a sampling point for digital predistortion. Preferably, the radio remote unit performs power calibration using the pseudo pilot: the radio remote unit determines the power of the pseudo pilot according to the current cell configuration power, and adjusts the determined pseudo pilot power by the power factor; the radio remote unit Power calibration is performed using pseudo-pilot power transmit pseudo pilots. According to another aspect of the present invention, a power calibration apparatus is provided, comprising: a padding module configured to fill a pseudo carrier on a secondary carrier-free channel with a pseudo pilot; and a calibration module configured to use the pseudo pilot Power calibration. Preferably, the padding module is arranged to fill the pilot slots of the first secondary carrier on the channel without the primary carrier with dummy pilots. Preferably, the apparatus further includes: a receiving module, configured to receive a cell identifier sent by the baseband pool unit; and a generating module, configured to generate a pseudo pilot according to the cell identifier. Preferably, the apparatus further includes: a data filling module, configured to fill the time slot of the secondary carrier after filling the pseudo pilot; and the opening module is configured to use the time slot as the sampling point to enable the digital predistortion. Preferably, the calibration module comprises: a determining submodule, configured to determine the power of the pseudo pilot according to the current cell configuration power; an adjustment submodule, configured to adjust the power of the pseudo pilot determined by the power factor adjustment; and the transmitting submodule is set to Power calibration is performed using pseudo-pilot power transmit pseudo pilots. According to the present invention, the method of filling the pseudo-pilot on the channel without the main carrier and performing power calibration using the pseudo-pilot solves the problem that the power calibration of the channel without the main carrier cannot be performed in the related art, and further The effect of calibrating a channel without a primary carrier is achieved. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a schematic diagram of a channel carrying structure according to the related art; FIG. 2 is a flowchart of a power calibration method according to an embodiment of the present invention; FIG. 3 is a flow chart of power calibration according to Embodiment 3 of the present invention; 4 is a schematic diagram of a DPD turn-on flow according to Embodiment 3 of the present invention; and FIG. 5 is a structural block diagram of a power calibration apparatus according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. Embodiment 1 This embodiment provides a power calibration method, which can be used to implement power control when an RRU carries a cross-band cell in a TD-SCDMA access system. 2 is a flowchart of a power calibration method according to an embodiment of the present invention. As shown in FIG. 2, the method includes the following steps: Step S202: A radio remote unit fills a secondary carrier on a channel without a primary carrier with a pseudo pilot. Step S204, the radio remote unit performs power calibration using the pseudo pilot. In the related art, only the primary carrier has a pilot, and therefore, the channel having the primary carrier can be power-controlled by the pilot. However, the inventors have found that the secondary carrier has no pilot, and therefore, the prior art cannot Power control is performed on channels without a primary carrier. In this embodiment, by using a pseudo pilot (for example, a SYNC_DL sequence) on a channel without a primary carrier, and using the pseudo pilot as a pilot for power control, power control is performed on a channel without a primary carrier. In this embodiment, the power control of the channel without the primary carrier may be performed by using the pilot to perform power control on the channel with the primary carrier in the related art, and details are not described herein again. Step S202 can adopt multiple implementation manners, and only one of the preferred modes is described. The BP and the radio remote unit fill the pilot time slot of the first secondary carrier on the channel without the primary carrier with a dummy. Pilot. This embodiment provides a specific filling position of the pseudo pilot, which has the advantage of being easy to implement. It should be noted that other filling positions can be easily conceived by those skilled in the art as long as it is on the secondary carrier on the channel without the primary carrier. The technical effect of the present invention can be achieved by filling the pseudo pilot. In a preferred implementation of the embodiment of the present invention, before the step S202, the method may further include: the radio remote unit receiving the cell identifier (cell ID, or Cell) sent by the baseband unit (BBU) Parameter ID), then, generate a pseudo pilot based on the cell identity. In this embodiment, the pseudo pilot is generated according to the cell identifier, so that the pseudo pilot can be more in line with actual needs, thereby effectively performing power calibration. The radio remote unit may generate a pseudo pilot according to the correspondence between the cell identifier and the pilot. In another preferred implementation manner of the embodiment of the present invention, after the step S202, the method may further include: the radio remote unit fills data in one time slot of the secondary carrier; and the radio remote unit uses the time slot as the sampling point. The opening of digital predistortion. This embodiment achieves the opening of digital pre-distortion by filling data on time slots. Preferably, the time slot of the padding data may be TS0. Selecting TS0 instead of the time slot filling data of other transport services can reduce the impact on service transmission. Preferably, the step S204 may include: the radio remote unit determines the power of the pseudo pilot according to the current cell configuration power, and adjusts the determined pseudo pilot power by the power factor; the radio remote unit uses the pseudo pilot power transmission pseudo. Pilot, perform power calibration. This embodiment enables power calibration using pseudo pilots. Embodiment 2 This embodiment adopts a field programmable gate array (Field Programable Gate) by using a pilot slot of a first secondary carrier on a channel without a primary carrier (or a single-channel RRU without a primary carrier on the RRU). Array, abbreviated as FPGA), fills the pseudo-pilot (for example, the SYNC_DL sequence) for power calibration. Since the SYNC_DL sequence in a cell is unique, the Cell Parameter ID that is sent to the RRU by the BBU can be translated and filled by the interface of the interface between the RRU and the BBU, that is, the interface between the RRU and the BBU. SYNC_DL sequence. The control of the power level of the padding data can be implemented by the maximum transmit power of the RRU air interface and the baseband data delivered by the BBU obtained by the FPGA (for example, IQ data, where I is an in-phase component, The projection of the representative vector on the horizontal axis; Q is the 90 degree phase shift (Quadrate) component. The IQ data is the baseband data after quadrature modulation. I is the component on the X axis, and Q is the component on the y axis. The baseband data can be used instead. There is a strict correspondence between the powers. Therefore, it is only necessary to estimate the power of the filled dummy data through the cell configuration power, and adjust the power factor of the FPGA to ensure the pseudo pilot power. The corresponding change in the maximum transmit power of the cell. The DPD related function can be implemented in the following manner: The RRU performs equalization processing of the transmission and feedback signals before the DPD starts, wherein the equalization is performed by the RRU system software after the cell is established, according to a digital signal processor (Digital Signal Processor, referred to as DSP) calculates the difference between the transmit and feedback signals of a certain time slot (for example, TS0) of the carrier to adjust the gain of the feedback channel; then, according to the existing cell establishment process and DPD, the equalization and formal adaptation process are started. The specific process includes:

1. RRU spontaneous test data of TS0 time slot;

2. The RRU performs frequency point validity check; 3. The power calibration initiates open loop power calibration;

4, DPD control sub-module (RRU DSP control module, referred to as RDSP) hardware set intermediate frequency, Crest Factor Reduction (CFR), etc.;

5. The RDSP calculates the attenuation of the downlink digital attenuator value according to the open loop power calibration; 6. The RDSP sets the feedback channel digitally controlled attenuator to full attenuation;

7. RDSP obtains the power difference (does a power detection), and re-adjusts the downlink digital attenuator according to the detected power;

8. The RDSP repeatedly reads the DSP power difference (Errorpwr), and adjusts the feedback channel attenuation and the digital equalizer (eq) according to the difference until the Errorpwr meets the power DPD algorithm matching requirement. The power calibration and the power detection can be implemented in the following manners: For the power detection and the VSWR detection, after the open loop power calibration is completed, the RRU initiates the detection of the power, and detects the downlink pilot time slot (Downlink Pilot Time Slot, respectively). For the forward power and reverse power of DWPTS), then, the standing wave ratio is calculated according to the detected reverse and forward power, and then the corresponding closed loop power calibration is performed according to the antenna port power estimated by the forward detection. When a multi-channel RRU is used to carry a cross-band cell, or a multi-channel RRU is used to carry a cross-band cell, the power control method provided in this embodiment can be used to save the cost of developing a wide-band power amplifier. In addition, in the embodiment, by using the software method, the purpose of completing the related functions without changing the hardware conditions can be achieved. Embodiment 3 The BBU and the RRU add a cell parameter configuration message. After receiving the message, the RRU determines whether the configured cell has a primary carrier. If there is no primary carrier, notifies the RRU main control module to initiate an open loop power calibration. After the BBU establishes the configuration for the RRU, the BBU configures the Cell Parameter ID to the RRU. The RRU notifies the main control module to initiate an open loop power calibration according to the condition of the cell main carrier. After receiving the cell parameter configuration message sent by the RRU master configuration module, the RRU master module sets the transmit pseudo-main carrier data, and notifies the FPGA to send the data of the corresponding carrier and triggers the open loop power calibration. After the cell is established, if the RRU has no primary carrier, the RRU sends a training sequence to the designated channel in the DWPTS slot for VSWR detection. 3 is a flowchart of power calibration according to Embodiment 3 of the present invention, and FIG. 3 is a flowchart of a BBU establishing a cell without a primary carrier for performing open loop power calibration, and the process includes the following steps:

S302. After receiving the cell setup response message of the RRU, the BBU sends a Cell Parameter ID Configuration Request message to the RRU.

S304. After receiving the Cell Parameter ID Configuration Request message, the RRU sends a Cell Parameter ID Configuration Response message to the BBU. S306, the RRU detects whether the configured cell has a primary carrier, and if the cell has a primary carrier, does not process; if the cell does not have a primary carrier, the RRU control configuration module sends a message to the RRU main control module to notify the RRU main control module of the cell parameter. Configuration, where the parameter configuration includes: a Cell Parameter ID, and a Cell Parameter ID is sent by the BBU to the RRU. S308. The RRU calculates a Sys_group_No (synchronization code group number) according to the obtained Cell Parameter ID. If it is detected that the cell has no primary carrier, the RRU looks for Carrier_No (the minimum frequency sequence number of the configured cell), and Carrier_No can be obtained by looking up the table.

S310, the RRU adjusts the power according to the cell power P_factor (calculated amplitude factor), so as to achieve the purpose of achieving stable power. S312, the RRU places the TS0 data according to Sys_group_No, P_factor, and TS0 (slot zero)

The corresponding address of the FPGA; the RRU places the DWPTS data to the corresponding address of the FPGA according to Sys_group_No, P_factor and DWPTS (downlink pilot time slot).

S314, the RRU sends a time slot enable according to the antenna serial number, the carrier number Carrier_No, and the slot number, and sets the DWPTS time slot and the TS0 time slot data transmission enable of the FPGA respectively; the RRU main control module initiates the open loop power calibration.

S316, the RRU main control module receives the open loop power calibration completion information sent by the power calibration module, and then stops transmitting the TS0 time slot data, and triggers closed loop power detection.

S318, RRU power calibration module performs standing wave ratio detection.

S320: The RRU main control module receives the information about the completion of the power detection fed back by the power calibration module, and then stops transmitting the DWPTS test data. The DPD needs to be enabled in the open loop process, and the DPD solution needs to capture a maximum power to start the DPD process on the TS0. The carrier without the primary carrier does not have the physical control channel (PCCH) power. Therefore, a set of data needs to be filled on TS0 in order to complete the DPD opening process. 4 is a schematic diagram of a DPD opening process according to Embodiment 3 of the present invention. As shown in FIG. 4, the DPD opening process includes:

S402. The RRU software sets the IQ data power of the TS0 training sequence according to the maximum power configuration value in all valid single channels. S404, the RRU software writes the IQ training sequence to a TSO downlink buffer random access memory (RAM) provided by the FPGA.

S406, the RRU software sets the TSO time slot training sequence of the minimum effective carrier to be enabled, and the channel is enabled.

S408, in the normal mode, the FPGA determines that the TS0 time slot training sequence is enabled to be true (TRUE), and the 864chip data in the buffer area is filled into the downlink TS0 time slot, and the training sequence is sent in the designated channel of the designated carrier. The data of all valid carriers of the TS0 slot on the specified channel provided by the IR interface is not delivered.

S410: The DPD of the RRU converges on the designated channel of the specified carrier, and enters an active state; wherein, if the multiple attempts cannot enter the working state, the alarm is reported.

S412, after the DPD enters the working state or reports the alarm, the RRU software sends the TS0 time slot training sequence of the least effective carrier and the channel enable to enable.

S414, in the normal mode, the FPGA determines that the TS0 time slot training sequence is enabled to be false (FALSE), and the TS0 time slot data provided by the IR interface is filled into the downlink TS0 time slot, and is sent. Embodiment 4 This embodiment provides a power calibration apparatus, which may be an RRU. 5 is a structural block diagram of a power calibration apparatus according to an embodiment of the present invention. As shown in FIG. 5, the apparatus includes: a filling module 52 configured to fill a pseudo carrier on a secondary carrier-free channel with a pseudo pilot; 54 is coupled to the fill module 52 and is configured to use a pseudo pilot for power calibration. In the related art, only the primary carrier has a pilot, and therefore, the channel having the primary carrier can be power-controlled by the pilot. However, the inventors have found that the secondary carrier has no pilot, and therefore, the prior art cannot Power control is performed on channels without a primary carrier. In this embodiment, by using a pseudo pilot (for example, a SYNC_DL sequence) on a channel without a primary carrier, and using the pseudo pilot as a pilot for power control, power control is performed on a channel without a primary carrier. The filling module 52 can adopt various implementation manners. Only one of the preferred modes is described. The filling module 52 is configured to fill the pilot time slot of the first secondary carrier on the channel without the primary carrier with a dummy. Pilot. This embodiment provides a specific fill location for the pseudo pilot with advantages that are easy to implement. In a preferred implementation of the embodiment of the present invention, the foregoing apparatus may further include: a receiving module, configured to receive a cell identifier sent by the baseband pool unit; and a generating module, coupled to the receiving module, configured to generate a pseudo pilot according to the cell identifier. In this embodiment, the pseudo pilot is generated according to the cell identifier, so that the pseudo pilot can be made. More in line with actual needs, and thus effectively perform power calibration. The radio remote unit may generate a pseudo pilot according to the correspondence between the cell identifier and the pilot. In another preferred implementation manner of the embodiment of the present invention, the foregoing apparatus may further include: a data filling module, configured to fill a time slot of the secondary carrier after filling the dummy pilot; and opening the module, coupled to the data filling module , Set to use time slot as the sampling point for digital pre-distortion. This embodiment achieves the opening of digital pre-distortion by filling data on time slots. Preferably, the time slot of the padding data may be TS0. Selecting TSOs instead of slotting data for other transport services can reduce the impact on traffic. Preferably, the calibration module 54 may include: a determining submodule configured to determine a power of the pseudo pilot according to the current cell configuration power; an adjustment submodule coupled to the determining submodule, configured to determine the pseudo pilot by the power factor adjustment Power; a transmit sub-module coupled to the conditioning sub-module, configured to use a pseudo-pilot power transmit pseudo pilot to perform power calibration. This embodiment enables power calibration using pseudo pilots. In another embodiment, a power calibration software is also provided for performing the technical solutions described in the above embodiments and preferred embodiments. In another embodiment, a storage medium is provided in which the above power calibration software is stored. In summary, the embodiment of the present invention adopts a method of charging a pseudo pilot on a channel without a primary carrier, and performing power calibration using the pseudo pilot, thereby achieving the effect of calibrating a channel without a primary carrier. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

1. A power calibration method, comprising:

The radio remote unit fills the secondary carrier on the secondary carrier-free channel with a pseudo pilot; the radio remote unit performs power calibration using the pseudo pilot.

2. The method according to claim 1, wherein the radio remote unit fills the pseudo pilot on the secondary carrier on the channel without the primary carrier, including:

The radio remote unit fills the pseudo pilot on a pilot time slot of a first secondary carrier on the channel without the primary carrier.

The method according to claim 1, wherein, before the radio remote unit fills the secondary carrier on the secondary carrier-free channel, the method further includes:

Receiving, by the radio remote unit, a cell identifier sent by the baseband pool unit;

The radio remote unit generates the pseudo pilot according to the cell identifier.

The method according to claim 1, wherein after the radio remote unit fills the secondary carrier on the channel without the primary carrier, the method further includes:

The radio remote unit fills data on one time slot of the secondary carrier;

The radio remote unit performs the digital pre-distortion on by using the time slot as a sampling point.

The method according to any one of claims 1 to 4, wherein the radio remote unit performs power calibration using the pseudo pilot:

The radio remote unit determines the power of the pseudo pilot according to the current cell configuration power, and adjusts the determined power of the pseudo pilot by using a power factor; the radio remote unit uses the power of the pseudo pilot The pseudo pilot is transmitted and power calibration is performed.

6. A power calibration device comprising:

a padding module, configured to fill a pseudo-carrier on a secondary carrier on a channel without a primary carrier; and a calibration module configured to perform power calibration using the pseudo pilot. The apparatus of claim 6, wherein the padding module is configured to fill the pseudo pilot on a pilot time slot of a first secondary carrier on the channel without a primary carrier. The device according to claim 6, wherein the device further comprises:

a receiving module, configured to receive a cell identifier sent by the baseband pool unit;

And generating a module, configured to generate the pseudo pilot according to the cell identifier. The device according to claim 6, wherein the device further comprises: a data filling module, configured to fill the time slot of the secondary carrier after filling the pseudo pilot;

The module is turned on, and is set to use the time slot as a sampling point for digital pre-distortion. The apparatus according to any one of claims 6 to 9, wherein the calibration module comprises: a determining submodule, configured to determine a power of the pseudo pilot according to a current cell configuration power; and an adjustment submodule, set to The power of the pseudo pilot determined by power factor adjustment; a transmit submodule configured to transmit the pseudo pilot using power of the pseudo pilot to perform power calibration.