CN1281083C - Correction method and device of intelligent antenna subsystem - Google Patents

Abstract

A calibration method and device for a smart antenna subsystem, used in a frequency division duplex-wideband code division multiple access system, which is mainly formed by linking a smart antenna with a calibration detection system, and the calibration method includes pre-calibration and detection of each Each cable in the antenna unit and the feeder cable, and the transmission parameters of the coupling structure formed by the connection of the coupler assembly and the calibration detection system are pre-tested, and the test results are stored in the calibration detection system; the system is in a normal transportation state, The transmission parameters of the uplink and downlink transceiver channels of the detection system are corrected in real time, and the correction weights are calculated and output to the baseband beamformer for weighting. The invention has the advantages that the calibration detection system works in parallel with the antenna system, can achieve calibration accuracy in the entire working frequency band, and can simultaneously correct the uplink and downlink channels.

Description

Calibration method and device for smart antenna subsystem

technical field

The present invention relates to a calibration method and device for a smart antenna radio frequency subsystem in a wideband code division multiple access system, in particular to a frequency division duplex-wideband code division multiple access (FDD-WCDMA) system smart antenna base station array radio frequency A method and device for correcting channel amplitude and phase errors.

Background technique

The essence of smart antenna is the core of array antenna technology and advanced signal processing method. The basic idea of a smart antenna is to use an antenna array composed of multiple antenna units (the coherence between the units satisfying the coherence characteristic) in the base station. By weighting the phase and amplitude of the signals received and transmitted by multiple antenna units, the antenna beam can be controlled. Direction and shape, and can form multiple independent beams to achieve directional transmission and reception for multiple users. In this way, spatial filtering can be achieved, co-channel (working carrier frequency) interference can be suppressed to the greatest extent, thereby increasing the channel (working carrier frequency) multiplexing rate, achieving the purpose of improving communication quality, increasing communication distance, and expanding system communication capacity.

However, in the actual smart antenna base station array system, there are many factors that are difficult to determine that cause the inconsistency of the array channels, that is, there are array errors. Array errors can be divided into time-invariant errors and time-varying errors. The time-invariant error includes the errors caused by the antenna arrangement, such as the geometric position difference of the array element, the mutual coupling effect between the array elements, the difference of the antenna pattern, the difference of the feeder between each array element, etc. These errors do not change with the environment such as temperature. Variations can be accurately measured and can be corrected at baseband. The time-varying error refers to the phase and gain difference of the amplifier that changes with the ambient temperature, time, and operating frequency among the RF channels of the array, the aging of the mixing device, the filter delay and its amplitude-frequency phase-frequency characteristic distortion, and the quadrature modem I The error caused by the inconsistency of the channel frequency response caused by /Q imbalance. In this way, the real channel characteristics will be quite different from the ideal characteristics. The performance of the baseband beamforming algorithm is closely related to the characteristics of the array, and the error of the array channel will affect the position of the null point and the depth of the zero trap and reduce the performance of the algorithm. It will cause changes in beam shape and out of control of power resources, which will affect system performance. Therefore, the correction of array errors is a key technology to be solved in the realization of smart antennas.

In order to accurately form the uplink receiving beam and downlink transmitting beam, it is necessary to know the performance difference of the array channel in advance, or know the amplitude and phase change error of the radio frequency signal after the array channel responds. While the system is running normally, the correction weight of the error between the array channels is obtained through real-time detection and calculation, and the digital weighted compensation is performed in the baseband beamformer to achieve the purpose of correcting the channel amplitude and phase error. The essence of channel error online correction is to track and compensate channel amplitude and phase characteristics, minimize the relative error between channels, and meet the control accuracy requirements of uplink and downlink beamforming algorithms.

There are roughly three types of correction techniques for existing smart antenna arrays: (1) Direct measurement method: that is, direct pre-measurement of each set of transceivers, low-noise amplifiers, linear power amplifiers, duplexers, and antenna feeders to obtain the After the amplitude and phase data are coupled into a set of correction and compensation data, they are recorded on the baseband and pre-corrected during beamforming. The disadvantage of this method is that the process is complicated, it is difficult to carry out on-site and put into system operation, and it is difficult to ensure the accuracy; (2) the use of beacon transceivers in the far field area for detection and correction requires no multipath propagation, which is difficult to achieve in actual systems (3) In the time division duplex system, continuous wave signals are used for measurement and correction, for example; recently retrieved patent documents about WCDMA adaptive array antenna/smart antenna array channel correction technology: such as A) U.S. Patent US6157340: Adaptive antenna array subsystem calibration; B) US Patent US6124824: Adaptive antenna array system calibration; these two patents are both patented methods of TDD-WCDMA time division duplex system, the system uses continuous wave signal for measurement and calibration. When correcting, the system is shut down or performed in a given time slot.

The patent documents related to correction retrieved above are all correction methods of adaptive array antenna/smart antenna base station of TDD-WCDMA (time division duplex) system. But for the FDD-WCDMA (Frequency Division Duplex) system, the above calibration methods are difficult to realize real-time online calibration of the smart antenna base station.

Contents of the invention

The technical problem solved by the present invention is to provide a method of injecting a known characteristic signal into each transceiver channel of the smart antenna base station array as a user signal (correction detection signal) in time-division after spreading and scrambling, and from the baseband multiple From the user signal, the known characteristic signal after the response of each transceiver channel is separated, and then the amplitude and phase errors of each transceiver channel are extracted from this signal, and the correction weight is calculated. After the calculated correction weight is verified first, then The output is sent to the beamformer of the smart antenna base station for weighting, so that the channel characteristics are consistent, and thus, the method for real-time correction of the channel amplitude and phase errors of the smart antenna base station array of the FDD-WCDMA system.

Another technical problem to be solved by the present invention is to provide a device for realizing the above correction method in the smart antenna base station of the FDD-WCDMA system.

The correction method of the smart antenna subsystem of the present invention includes: (1), before the system is put into use, 12 cables in the antenna array and the 12 cables in the feeder cable are pre-corrected and tested, and the results are stored in the smart Inside the antenna base station, the characteristics are: (2) After linking the smart antenna subsystem with the calibration detection system, the transmission coefficients CRij and CTij of the uplink and downlink coupling paths of the coupling structure are separately tested and corrected and stored in the calibration detection system. In the system, the coupling structure includes an uplink radio frequency signal switcher (in the correction detection system), an uplink correction radio frequency signal coupling cable, a coupler assembly (in the smart antenna), a downlink correction radio frequency signal coupling cable and The downlink radio frequency signal switcher, (3), start the system, real-time calibration detects the transmission coefficient Ri and Ti (i=1, 2, ...12), calculate the correction weight and output it to the baseband beamformer for weighting.

In the above-mentioned method of the present invention, the steps of pre-testing and correcting the transmission coefficients of the uplink and downlink coupling channels of the coupling structure and correcting the transmission coefficients of the uplink and downlink transmission and reception channels in real time and weighting the baseband beamformer include:

The first step, 1), uses a vector network analyzer to pre-calibrate the coupling structure, and stores the transmission coefficient of the coupling structure in the calibration detection system, 2), setting the antenna array, feeder cable, coupler assembly, calibration detection system System, transceiver array, beamformer, uplink correction radio frequency signal coupling cable, downlink correction radio frequency signal coupling cable, correction detection system and the digital communication interface between the smart antenna base station beamformer constitute the real-time correction link of the smart antenna base station, 3), Keep the smart antenna base station system in normal operation;

The second step is to perform uplink channel correction, including: 1), the correction detection system applies for a user scrambling code to the base station protocol layer, 2), and detects the response of all 12 uplink receiving channels of the smart antenna when it is at the jth working carrier frequency The final known characteristic signal is sampled and stored, 3), the correction weights of the uplink receiving channel errors at the jth working carrier frequency are obtained by using an algorithm, 4), the correctness of the uplink correction weights is checked, and no Repeat 2) and 3) in this second step correctly,

The third step is to perform downlink channel correction, including: 1), the correction detection system applies for a user spreading code to the base station protocol layer, 2), and detects all 12 downlink signaling channels of the smart antenna when it is at the jth working carrier frequency The known characteristic signal after the response is sampled and stored, 3), the correction weight of each downlink channel error at the jth working carrier frequency is obtained by using an algorithm, 4), the correctness of the downlink correction weight is checked, it is not correct Repeat 2) and 3) in this third step,

The fourth step is to send the correction weights of the uplink or downlink at a given working carrier frequency to the beamformer for weighting together with other weight coefficients, release the applied scrambling code or spreading code, and a correction is completed.

1) in the first step includes: pre-aging the uplink radio frequency signal switcher and downlink radio frequency signal switcher in the coupling structure and always in a constant temperature environment, using a vector network analyzer to pre-measure the coupling structure on the upper , The transmission coefficient of each working carrier frequency in the downlink working frequency band; and the transmission coefficient of its reception and transmission has been stored in the calibration detection system, and the transmission coefficient of the coupling structure is used as the basis for calculation when the transceiver channel is corrected.

2) in the second step includes: the uplink correction detection signal source spreads a known characteristic (frequency, amplitude, phase) signal to 3.84MHz, and the scrambling is modulated by a modulator to output a determined Level signals are injected into one of the 12 receiving channels in the corrected uplink receiving array through the uplink radio frequency signal switcher, 12 uplink coupling cables, and coupler components; the corrected uplink receiving channel The multi-user digital signal after the response enters the baseband digital signal switcher through 12 corresponding digital communication interfaces and enters the uplink detection signal separator, and separates the known characteristic signal after the response of the uplink receiving channel from the multi-user composite signal And sample and store in the uplink correction weight generator; complete the above detection process for the 12 uplink receiving channels in sequence.

3) in the second step includes: taking the known characteristic signal after a certain receiving channel response as a reference, the known characteristic signal after each receiving channel responds is obtained by using an algorithm in the uplink correction weight generator Correction weights of errors in each of the 12 receiving channels.

4) in the second step includes: using the correction weights of each receiving channel to modify the modulation signal of the uplink correction detection signal source, that is, the known characteristic (frequency, amplitude, phase) signal, and repeating the above error detection process, Turn to the fourth step until the error correction weight is correct.

2) in the third step includes: the downlink correction detection signal source spreads a known characteristic (frequency, amplitude, phase) signal to 3.84MHz, transmits it to the downlink beamformer by the digital communication interface after scrambling Combined with other user signals and then modulated on a given working carrier frequency by one of the 12 transmitting channels in the corrected transmitting array, the output signal passes through the coupler assembly and the feeder cable to the antenna array, and at the same time The multi-user signal containing the corrected detection signal in the corrected signaling channel passes through 12 downlink coupling cables and the downlink radio frequency signal switcher to the demodulator, and the multi-user digital signal after the response of the demodulator enters the downlink detection signal separator from the multi-user The known characteristic signal is separated from the synthesized signal to be sampled and stored in the downlink correction weight generator, and the above detection process is completed for the 12 downlink signaling channels in turn.

3) in the third step includes: taking the known characteristic signal after the response of a certain signaling channel as a reference, the known characteristic signal after the response of each signaling channel adopts an algorithm in the downlink correction weight generator to obtain 12 Correction weights of each signaling channel error in each signaling channel.

4) in the third step includes: using the correction weights of each signaling channel to correct the modulation signal of the downlink correction detection signal source, that is, the known characteristic (frequency, amplitude, phase) signal, and repeating the above error detection process, Turn to the fourth step until the error correction weight is correct.

The fourth step includes: sending the correction weights of each receiving channel error in the uplink 12 receiving channels into the uplink beamformer and other weight coefficients (comprising uplink correction weights of antennas and feeder cables) by the digital communication interface. value) are weighted together, the applied scrambling code is released, and an uplink correction is completed; the correction weights of the errors of each of the 12 downlink transmission channels are sent to the downlink beamformer and other weight coefficients ( Including the downlink correction weights of the antenna and the feeder cable) are weighted together, the applied spreading code is released, and a downlink correction is completed.

The correction device formed by the correction method of the smart antenna subsystem of the present invention is realized according to the following technical solutions:

It includes a smart antenna subsystem mainly composed of an antenna array, a feeder cable, a coupler assembly, a transceiver array, and a beamformer that are sequentially connected in a bidirectional circuit, and is characterized by a correction detection system that is coupled by an uplink correction radio frequency The cable and the downlink correction radio frequency signal coupling cable are connected with the coupler assembly in a bidirectional circuit and a digital communication interface is provided to bidirectionally connect the beamformer. And also reside on the coupling structure, the downlink coupling path detection program and the smart antenna base station calibration program in the calibration detection system.

The correction detection system includes a downlink correction detection system and an uplink correction detection system, and is linked with the smart antenna subsystem to form a downlink correction link and an uplink correction link; the transceiver array includes a sending array and a receiving array; The beamformer includes a downlink beamformer and an uplink beamformer.

The downlink correction detection system includes a downlink radio frequency signal switcher, a demodulator, a downlink detection signal separator and a downlink correction weight generator connected in sequence in a circuit, and a downlink correction detection system bidirectionally connected with the downlink correction weight generator signal source.

The uplink correction detection system includes an uplink correction detection signal source, a modulator, and an uplink radio frequency signal switcher sequentially connected in a circuit, and a baseband digital signal switcher, an uplink detection signal separator and an uplink correction weight generation circuit connected in sequence device, and the uplink correction weight generator is bidirectionally connected with the uplink correction detection signal source.

The downlink correction link includes a downlink beamformer, a signaling array, a coupler assembly, a feeder cable and an antenna array sequentially connected by a circuit, and a downlink correction radio frequency signal coupling cable, a downlink correction A detection system, and two digital communication interfaces connecting the correction detection system and the beamformer of the smart antenna base station.

The uplink correction link includes an antenna array, a feeder cable, a coupler assembly, a receiving array, an uplink beamformer, and an uplink correction RF signal coupling cable connected to the uplink correction detection system from the coupler assembly in sequence. 13 digital communication interfaces connecting the correction detection system and the beamformer of the smart antenna base station.

The coupling structure is composed of an uplink radio frequency signal switcher, an uplink correction radio frequency signal coupling cable, a coupler assembly, a downlink correction radio frequency signal coupling cable, and a downlink radio frequency signal switcher which are sequentially connected by circuits. The coupling structure is used for coupling uplink and downlink correction detection signals. The coupler assembly is connected in series between the feeder cable and the transceiver array, and is composed of 12 independent uplink and downlink correction detection signal couplers fabricated on a PCB (i.e. brush circuit board) with microstrip lines. Together, each coupler includes an uplink injection signal coupling port and a downlink injection signal output coupling port. The uplink calibration RF signal coupling cables include 12 coupling cables. The downlink correction RF signal coupling cables also include 12 coupling cables. The uplink radio frequency signal switcher is a 12-to-1 radio frequency switch component, which sends the uplink correction detection signal output from the modulator to the selected correction receiving channel in time division. The downlink RF signal switcher is also a 12-to-1 RF switch component, which sends the output of the downlink calibration detection signal from the selected calibration signaling channel to the demodulator in time division. The 12 uplink injection signal coupling ports in the coupler assembly are connected to the uplink radio frequency signal switcher through 12 uplink coupling cables, and the 12 downlink injection signal output coupling ports in the coupler assembly are connected to the downlink radio frequency signal through 12 downlink coupling cables switcher. The uplink radio frequency signal switcher and downlink radio frequency signal switcher in the coupling structure are pre-aged and placed in a constant temperature environment to ensure the stability of the transmission coefficient of the entire coupling structure. When the coupling structure is loaded into the system, pre-calibration of the coupling structure has been carried out separately, and its receiving and transmitting transmission coefficients have been stored in the calibration detection system. The transmission coefficient of the above-mentioned coupling structure is used as a basis for correction of the transceiver channel.

When the downlink correction link is working, the downlink correction detection signal source spreads and scrambles the known characteristic signal, and then outputs it to the downlink beamformer of the smart antenna base station through the digital communication interface and combines it with other user signals to enter the corrected sending signal. One of the 12 transmitting channels in the array is connected to the antenna array by the coupler assembly and the feeder cable. At the same time, the corrected transmitting channel contains the multi-user signal of the corrected detection signal, and is sent to the demodulator through the coupling structure To the downlink detection signal separator, separate the known characteristic signal from the multi-user composite signal and provide it to the downlink correction weight generator, and calculate the correction weight in the downlink correction weight generator. After checking that the error correction weight is correct, the confirmed correction weight is sent to the downlink beamformer through the digital communication interface to be weighted together with other weight coefficients.

When the uplink correction link is working, the uplink correction detection signal source spreads and scrambles the known characteristic signal and outputs it to the modulator, and injects it into a certain channel of the receiving channel in the corrected receiving array through the coupling structure, and at the same time, the The antenna array and other multi-user signals received by the feeder cable also enter the corrected receiving channel through the coupler assembly, and the output baseband digital signal enters the baseband digital signal switcher through the corresponding 12 digital communication interfaces, and is detected by the uplink The signal separator separates the known characteristic signal from the multi-user composite signal and supplies it to the uplink correction weight generator, and calculates the correction weight in the uplink correction weight generator. After checking that the error correction weight is correct, the confirmed correction weight is sent to the uplink beamformer through the digital communication interface to be weighted together with other weight coefficients.

The receiving array includes 12 receiving channels with the same structure, and each receiving channel includes a low-noise amplifier, a receiver and a digital-to-analog converter connected to a duplexer in turn; similarly, the sending The signaling array includes 12 signaling channels with the same structure, and the signaling channels include digital-to-analog converters, transmitters, and linear power amplifiers that are sequentially connected in a circuit, and the output end of the linear power amplifier is connected to the signaling channel of the duplexer. input.

The demodulator has the same structure as a receiving channel of the smart antenna base station.

The modulator has the same structure as a transmitter and a digital-to-analog converter in the signaling channel of the smart antenna base station.

The digital communication interface connects the correction detection system with the beamformer of the smart antenna.

The positive effect of the present invention is: according to the method and device described in the present invention, the correction of the channel amplitude and phase error of the smart antenna base station array of the FDD-WCDMA system can be realized. The calibration method has the following advantages: 1), the online calibration detection system works in parallel with the smart antenna system without affecting system performance; 2), the range of calibration channels is comprehensive, including duplexers, low noise amplifiers, linear power amplifiers, transceivers , digital-to-analog converter, analog-to-digital converter, no need to correct the error of the duplexer in advance; 3), the change of the array channel amplitude and phase caused by maintenance, unit replacement, aging and other reasons can be corrected; 4), in the whole The working frequency band can achieve the required correction accuracy; 5), the uplink and downlink channels can be calibrated at the same time.

Description of drawings

The accompanying drawings of the present invention are briefly described as follows:

FIG. 1 is a schematic diagram of the device structure of an FDD-WCDMA system smart antenna base station according to the present invention.

FIG. 2 is a schematic diagram of the device structure of the downlink correction link in FIG. 1 .

FIG. 3 is a schematic structural diagram of an uplink correction link device in FIG. 1 .

FIG. 4 is a device structural block diagram of a first transceiver channel in the transceiver array in FIG. 1 .

Fig. 5 is a corrected block diagram of the coupling structure of the coupler assembly, the coupling cable, and the upper and lower radio frequency signal switchers in the smart antenna base station in Fig. 2 and Fig. 3 .

Fig. 6 is a flow chart of the pre-calibration method of the coupling structure in the present invention.

Fig. 7 is a flow chart of the method for calibrating the smart antenna base station of the FDD-WCDMA system according to the present invention.

Detailed ways

The following provides an embodiment of the present invention according to Fig. 1 to Fig. 7, and further illustrates the method and device of the present invention.

Please refer to FIG. 1 , which shows the structure of an FDD-WCDMA system smart antenna base station using the method and device of the present invention. It mainly includes an antenna array 100, a feeder cable 101, a coupler assembly 102, a transceiver array 104, a beamformer 105, and an uplink and downlink correction radio frequency signal coupling cable 106, 107 and the coupler assembly 102, which are sequentially connected in a two-way circuit. A correction detection system 103 connected in two directions, and a digital communication interface 108 connecting the correction detection system 103 and the beamformer 105 . The above-mentioned transceiver array 104 is composed of 12 transceiver channels, and the interface signals with the beamformer 105 are digital signals; the said digital communication interface 108 includes 280, 281, 282, 283, 284, ..., 294; the above-mentioned The coupling component 102 is composed of 12 uplink and downlink correction RF signal couplers fabricated on a PCB with microstrip lines.

Please refer to FIG. 2. FIG. 2 shows the structure of the downlink correction link in FIG. 1, which includes a downlink beamformer 105A sequentially connected by circuits, and a sending array composed of 12 sending channels 237, 238, ..., 248 104A, a coupler assembly 102 made up of 12 correcting radio frequency signal couplers 225, 226, ..., 236, a feeder cable 101 made up of 12 nearly identical cables 213, 214, ..., 224 and 12 antennas The antenna array 100 composed of units 201, 202, ..., 212, the downlink correction RF signal coupling cable 107 composed of cables 261, 262, ..., 272, the downlink correction detection system 103A, and digital communication interfaces 280, 281.

The downlink correction detection system 103A includes a downlink radio frequency signal switcher 251, a demodulator 252, a downlink detection signal separator 253, a downlink correction weight generator 254, and a downlink correction weight generator 254 that are sequentially connected in a circuit. The downlink correction detection signal source 255 is connected in two directions.

In the FDD-WCDMA system smart antenna base station structure shown in Figure 1, there are 12 transceiver links in total, and the sending links are composed of 12 columns in Figure 2: the first sending link is composed of antenna unit 201, cable 213 , correction RF signal coupler 225, and signaling channel 237; the second row of sending chain is composed of antenna unit 202, cable 214, correcting radio frequency signal coupler 226, and signaling channel 238; ...; the twelfth row of sending chain It is composed of an antenna unit 212, a cable 224, a correction RF signal coupler 236, and a signaling channel 248.

Referring to FIG. 3 , FIG. 3 shows the structure of the uplink correction link in FIG. 1 . It includes an antenna array 100 composed of 12 antenna units 201, 202, ..., 212 connected by circuits in turn, a feeder cable 101 composed of 12 nearly identical cables 213, 214, ..., 224, and a feeder cable 101 composed of 12 Calibrate the coupler assembly 102 composed of RF signal couplers 225, 226, ..., 236, the receiving array 104B composed of 12 receiving channels 337, 338, ..., 348, the uplink beamformer 105B, and the uplink calibration detection system 103B, from the uplink correction detection system 103B, the uplink correction radio frequency signal coupling cable 106 composed of cables 301, 302, ..., 312 connected to the coupler assembly 102 and the digital signal connecting the uplink correction detection system 103B and the uplink beamformer 105B in two directions Communication interfaces 282, 283, 284, . . . , 294.

The uplink correction detection system 103B includes an uplink correction detection signal source 353, a modulator 352 and an uplink radio frequency signal switcher 351 sequentially connected in a circuit, a baseband digital signal switcher 354 connected in sequence, an uplink detection signal separator 355, an uplink A correction weight generator 356; and the uplink correction detection signal source 353 is connected to the uplink correction weight generator 356 in a bidirectional circuit.

In the FDD-WCDMA system smart antenna base station structure shown in Figure 1, there are 12 transceiver links in total, and the receiving links are composed of 12 columns in Figure 3: the first column of receiving links includes antennas that are sequentially connected in a circuit Unit 201, cable 213, correcting radio frequency signal coupler 225, and signaling channel 337; the second column receiving link includes an antenna unit 202, cable 214, correcting radio frequency signal coupler 226, and signaling channel 338 sequentially connected by circuits; . . . ; the twelfth column of the receiving link includes an antenna unit 212 , a cable 224 , a correcting radio frequency signal coupler 236 , and a signaling channel 348 connected in sequence.

Referring to FIG. 4 , the figure describes the structure of the first receiving channel in the smart antenna base station array, that is, the structures of the first receiving channel 337 and the first sending channel 237 , and the structures of each receiving channel are the same. Similarly, the structure of each signaling channel is also the same. In the figure, the upper end of the duplexer 401 is connected to point A1 in FIG. 5 , its receiving output end is connected to the first receiving channel 337 , and its sending input end is connected to the linear power amplifier 405 . The receiving channel 337 is followed by a duplexer 401, which includes a low-noise amplifier (LNA) 402, a receiver 403, and an analog-to-digital converter (ADC) 404 connected in sequence. The signaling channel 237 includes a digital-to-analog converter (DAC) 407 , a transmitter 406 , and a linear power amplifier 405 sequentially connected in a circuit, and the duplexer 401 is connected to the signaling channel 237 .

Referring to Fig. 5, Fig. 5 has described the coupling structure 502 of the correction link radio frequency signal adopted in the FDD-WCDMA system smart antenna base station of the method and device of the present invention, and it is by the uplink radio frequency signal switcher 351 that is connected with circuit successively , the uplink correction radio frequency signal coupling cable 106, the coupler assembly 102, the downlink correction radio frequency signal coupling cable 107, and the downlink radio frequency signal switcher 251 form a coupling structure for injecting signals. Cables 301, 302, ..., 312 in Fig. 5 are coupling cables connecting corresponding couplers 225, 226, ..., 236 to the uplink RF signal switcher 351 respectively, and cables 261, 262, ..., 272 are respectively connecting corresponding coupling Coupling cables between switches 225, 226, . . . , 236 and downlink radio frequency signal switcher 251. Among Fig. 5, point A1, point B1 are the input and output ports of the 1st transceiver channel coupler 225; point A2, point B2 are the input and output ports of the 2nd transceiver channel coupler 226, ..., point A12, point B12 are the input and output ports of the twelfth transceiver channel coupler 236 . Point A1, point A2, ..., point A12 are connected to the output ends of duplexers of each transceiver channel, such as the upper end of duplexer 401, and points B1, point B2, ..., point B12 are connected to the lower end of each transceiver link antenna feeder . Point C is the connection point between the downlink radio frequency signal switcher 251 and the demodulator 252 , and point D is the connection point between the uplink radio frequency signal switcher 351 and the modulator 352 . The coupling structure 502 has been individually pre-calibrated before being installed in the smart antenna base station.

The uplink and downlink pre-calibration of the coupling structure 502 shown in Fig. 5 is carried out separately, and its downlink calibration includes: connecting a vector network analyzer 501 with the input ports A1, A1, The i-th port among A2, . . . , A12 is connected to the output point C of the downlink radio frequency signal switcher 251 . The output port B1, B2, ..., B12 of each transceiver channel coupler 225, 226, ... 236 to be calibrated at the same time is connected to a matching load, and the i-th port in the coupling structure 502 is measured respectively with a vector network analyzer 501 The transmission coefficients CTij of the corrected downlink coupling paths, where i=1, 2, . . . 12 represent 12 transceiver channels, and j=1, 2, . The transmission coefficients CTij of all downlink coupling paths of the coupling structure 502 are obtained through i×j tests. Its uplink calibration includes: inputting a vector network analyzer 501 and an uplink radio frequency signal switcher 351 into point D and connecting the output port A1, A2, ..., A12 of each transceiver channel coupler 225, 226 ... 236 to the i-th one port connection. At the same time, the output port B1, B2, ..., B12 of each transceiver channel coupler 225, 226...236 to be calibrated is connected to a matching load, and the i-th calibrated in the coupling structure is measured with a vector network analyzer 501 The transmission coefficient CRij of the uplink coupling channel, where i=1, 2, ... 12 represent 12 transceiver channels, and j=1, 2, ..., 12 represent 12 uplink operating carrier frequencies. The transmission coefficient CRij of all uplink coupling paths of the coupling structure is obtained through i×j tests.

The correction work of the present invention is that the correction detection system 103 forms a correction link with the FDD-WCDMA system smart antenna base station, detects the transmission coefficients Ri and Ti of each channel in real time, calculates the correction weights and outputs them to the baseband beamformer 105 for weighting. The principle of the present invention is described as follows: when the jth operating carrier frequency is given, the transmission coefficient of the signaling channel 237, 238, ..., 248 is Ti (i=1, 2, ... 12), the downlink coupling of the coupling structure 502 The path transmission coefficient is CTi, the transmission coefficient of the demodulator 252 is CR, the transmission coefficient of the receiving channels 337, 338, ..., 348 is Ri (i=1, 2, ... 12), and the uplink coupling path of the coupling structure 502 is The transmission coefficient is CRi, and the transmission coefficient of modulator 352 is CT; when setting downlink correction (see FIG. 2), the correction detection signal sent by point a1 is S1, and the signal separated by point b1 is STi; when uplink correction is set (see FIG. 3), the correction detection signal sent by point a2 is S2, and the signal separated by point b2 is SRi;

The output signal of the uplink correction link is: SRi＝Ri×CRi×CT×S2 (1)

The output signal of the downlink calibration link is: STi=Ti×CTi×CR×S1 (2)

The transmission coefficient of the uplink receiving channel is: Ri＝SRi/〔CRi×CT×S2〕 (3)

The transmission coefficient of the downlink signaling channel is: Ti＝STi/〔CTi×CR×S1〕 (4)

Taking the first channel as the reference channel, the equations (3) and (4) are:

The transmission coefficient of the uplink receiving channel is: Ri/R1=[SRi×CR1]/[SR1×CRi] (5)

The transmission coefficient of the downlink sending channel is: Ti/T1=[STi×CT1]/[CTi×ST1] (6)

In the formulas (5), (6), i=1, 2, ... 12. CR1, CRi, CT1, and CTi are determined by the coupling structure 502 in FIG. 5, and can be pre-calibrated and detected according to FIG. 6. SRi, SR1, STi, and ST1 are the outputs of the detection signal separation device of the calibration detection system, which can be detected in real time. Therefore, Ri/R1 and Ti/T1 can be calculated, and the correction weights of the receiving channel and the transmitting channel can be calculated.

Referring to FIG. 6 , the steps of the calibration method for the coupling structure 502 shown in FIG. 5 are described in the figure. The coupling structure 502 has been individually pre-calibrated before the smart antenna base station is put into use, and the obtained transmission coefficients CRij and CTij of the uplink and downlink coupling paths are stored in the calibration detection system 103 of the smart antenna base station.

The calibration process 60 of the uplink coupling path of the coupling structure described in FIG. 6 includes: step 601, start calibration; step 602, select the uplink coupling path for calibration; step 603, connect the system according to the test requirements of the uplink coupling path, and perform the first uplink Coupling path is corrected, get i=1: step 604, the operating carrier frequency of setting vector network analyzer 501 is the 1st in j operating carrier frequencies, get j=1; Step 605, set the working carrier frequency of vector network analyzer 501 The working carrier frequency is the jth working carrier frequency; Step 606, test the transmission coefficient CRij when the correction frequency of the i-th uplink coupling channel of the coupling structure is the jth working carrier frequency with the vector network analyzer 501 and record the test result; step 607, 608, by judging whether j is equal to 12, according to steps 605, 606 to complete the transmission coefficient CRij of all 12 operating carrier frequencies of the i-th uplink coupling path and recording the test results; steps 609, 610, by judging whether i is equal to 12 Follow steps 604 to 608 to complete the transmission coefficients CRij of all 12 uplink coupling paths at all 12 operating carrier frequencies, record the test results, and transfer to downlink coupling path calibration.

The downlink coupling path correction process 61 of the coupling structure 502 described in FIG. 6 includes: step 611, connect the system according to the downlink coupling path test requirements, and correct the first uplink coupling path, take i=1; step 612, set the vector network The working carrier frequency of analyzer 501 is the 1st in j working carrier frequencies, get j=1; Step 613, the working carrier frequency of setting vector network analyzer 501 is the jth working carrier frequency; Step 614, uses vector The network analyzer tests the transmission coefficient CTij when the correction frequency of the i-th downlink coupling path of the coupling structure is the j-th operating carrier frequency and records the test results; steps 615 and 616 are completed by judging whether j is equal to 12 or not according to steps 613 and 614 The transmission coefficient CTij of all 12 operating carrier frequencies of the i-th downlink coupling path and record test results; Steps 617 and 618, by judging whether i equals 12 or not, complete all 12 downlink coupling paths in steps 613 to 614 The transmission coefficient CTij at 12 operating carrier frequencies and record the test results; step 619, obtain the transmission coefficients CRij and CTij of all the uplink and downlink coupling paths, and then end the calibration of the coupling structure.

Referring to FIG. 7 , the figure describes the steps of the calibration method for all 12 uplink and downlink transceiver channels of the smart antenna base station. The coupling structure 502 has been calibrated separately according to FIG. 5 and FIG. 6 before being put into use, and the result is stored in the calibration detection system 103 of the smart antenna base station. Antenna units 201, 202, ..., 212 and feeder cables 213, 214, ..., 224 in the antenna array 100 have also been individually calibrated and tested before being put into use and the results are stored inside the smart antenna base station. The present invention does not contain Precalibration of the antenna array 100 and the feed cables 213, 214, . . . , 224.

The correction process of the uplink and downlink transceiver channels of the smart antenna base station in Figure 7 includes: Steps 701 and 702, the smart antenna base station system normally enters the working state; step 703, the calibration detection system 103 starts, and communicates with the baseband control part inside the smart antenna base station to shake hands; Step 704, the initial setting of the uplink receiving channel correction; Step 705, the correction detection system 103 obtains the working carrier frequency number j from the baseband control part, applies for a user scrambling code, selects the first of the 12 uplink receiving channels for correction, and takes i =1; Step 706, carry out the preset of the uplink radio frequency signal switcher 351 and the baseband digital signal switcher 354 corresponding to the i-th receiving channel; Step 707, the uplink correction detection signal source spreads and scrambles the known characteristic signal and outputs to The modulator up-converts the frequency to the jth working carrier frequency and outputs a given signal power. The signal is injected into the i-th uplink receiving channel through the uplink RF signal switcher and the selected i-th uplink correction RF signal coupler. A receiving channel includes a duplexer 401, a low-noise amplifier 402, a receiver 403, and an ADC analog-to-digital conversion 404. The digital signal output enters the baseband digital signal switcher 354, and the uplink detection signal separator 355 separates the response. known characteristic signal; step 708, sampling and saving the known characteristic signal after the i response; steps 709 and 710, judging whether all 12 uplink channels have been detected, if not detected then i=i+1 and press Steps 706, 707, and 708 continue; step 711, calculate the correction weight of the uplink channel; step 712, check the correction weight of each uplink receiving channel, and repeat steps 706 to 711 if they are not correct; step 713, correct the downlink transmission channel Initial setting; step 714, the correction detection system 103 obtains the working carrier frequency number (j) from the baseband control part, applies for a user spreading code, selects the first of 12 downlink transmission channels to correct, and gets i=1; step 715 , the downlink radio frequency signal switcher 251 is preset corresponding to the i-th transmission channel; step 716, the downlink correction detection signal source 255 spreads and scrambles the known characteristic signal and outputs it to the baseband downlink beamformer 105A and the selected The baseband and other user signals of the i-th corrected signaling channel are combined and passed through the i-th transmitter including DAC digital-to-analog conversion 407, transmitter 406, power amplifier 405, duplexer 401, and then through a coupler assembly and a feeder cable Output to the antenna array, and at the same time, the digital signal output by the coupler component through the downlink radio frequency signal coupling cable, the downlink radio frequency signal switcher, and the demodulator is separated by the downlink detection signal separator to separate the known characteristic signal after response; Step 717, sampling and saving the known characteristic signal after the i-th response; Steps 718, 719, judging whether all 12 downlink channels have been detected, if not detected, then i=i+1 and press steps 715, 716, 717 Continue; step 720, calculate the correction weight of the downlink channel; step 721, check the correction weight of the downlink channel, if it is not correct, repeat step 715 to step 720; step 722, output the correction weight of each uplink and downlink channel to the uplink and downlink The beamformers 105A and 105B weight together with other weight coefficients, and release the user scrambling code and spreading code; step 723, a real-time correction ends.

The 12 array elements in the FDD-WCDMA system smart antenna base station structure of the method and device of the present invention can form a three-sector linear array and a circular ring array. In the case of a circular array, each transceiver array uses the same local array signal source, and in the case of a three-sector linear array, the 4 transceiver arrays of each sector linear array use the same local array signal source. In order to realize real-time and fast correction of the system, when the system has a three-sector linear array structure, the four transceiver arrays of each sector linear array use the same local array signal source. At this time, the calibration is performed by sector, and the number of array elements is N=4.

Claims (10)

1. the bearing calibration of an intelligent antenna subsystem, its step comprises:

(1), before system comes into operation, to the antenna element in the aerial array (100) (201,202 ..., 212) and feeder cable (101) in cable (213,214 ..., 224) proofread and correct test in advance, and the result is kept at intelligent antenna base station inside, it is characterized in that: also have

(2), after intelligent antenna subsystem linked with correct detection system (103), test and proofread and correct the transmission coefficient CRij of the up-downgoing coupling path of coupled structure (502) earlier separately, CTij, and be stored in the detection system (103), this coupled structure (502) is to comprise successively with the up radiofrequency signal switch (351) in the correct detection system (103) of circuit connection, up correction radiofrequency signal coupling cable (106), coupler component in the smart antenna (102), downlink radio-frequency signal switch (251) in descending correction radiofrequency signal coupling cable (107) and the correct detection system (103);

(3), start-up system, the real-time transmission coefficient Ri and the Ti of each transceiver passage of correct detection uplink and downlink when given working carrier frequency j, the calculation correction weights are exported to base band Beam-former (105) and are weighted.

2. the bearing calibration of intelligent antenna subsystem according to claim 1, it is characterized in that: said (2) are weighted about the transmission coefficient of real-time each transceiver passage of detection uplink and downlink and to base band Beam-former (105) about transmission coefficient and (3) of proofreading and correct test coupled structure (502), and its step comprises:

The first step (71): 1) utilize vector network analyzer (501) that coupled structure (502) is proofreaied and correct (60 in advance, 61), and with the transmission coefficient of coupled structure (502) be stored in correct detection system (103), 2) be provided with by aerial array (100), feeder cable (101), coupler component (102), correct detection system (103), transmitting-receiving array (104), Beam-former (105), up correction radiofrequency signal coupling cable (106), Interface for digital communication (108) between descending correction radiofrequency signal coupling cable (107) and correct detection system (103) and intelligent antenna base station Beam-former (105) constitutes the real-time corrected link of intelligent antenna base station, 3) make intelligent antenna base station system be in normal operating condition;

Second step (72): carry out data feedback channel and proofread and correct, comprise: 1) correct detection system (103) is to user's scrambler of base station protocol layer application, 2) known features signal and the sampling behind up all 12 collection of letters channel responses of detection, preserve, 3) adopt algorithm to draw the correction weights of the up channel error of respectively collecting mail, 4) the up correction weights correctness of check, as incorrect then repeat this second the step (72) 2) and 3), the 3rd step (73): carry out down going channel and proofread and correct, comprise: 1) correct detection system (103) is to user's spreading code of base station protocol layer application, 2) known features signal and the sampling behind descending all 12 channel responses of posting a letter of detection, preserve, 3) adopt algorithm to draw the correction weights of descending each channel error, 4) the descending correction weights correctness of check, as incorrect then repeat this 3rd the step (73) 2) and 3), the 4th step (74): upstream or downstream are proofreaied and correct weights send into Beam-former (105) and the weighting in the lump of other weight coefficient, discharge the scrambler or the spreading code of application, once proofread and correct and finish.

3. the bearing calibration of intelligent antenna subsystem according to claim 2, it is characterized in that: 1 in the described first step (71)) comprising: with the up radiofrequency signal switch (351) in the coupled structure (502), downlink radio-frequency signal switch (251) also is in the isoperibol through aging in advance all the time, measure coupled structure (502) in advance last with vector network analyzer (501), transmission coefficient during each working carrier frequency of downlink working frequency range, and the transmission coefficient of its reception and emission is stored in correct detection system (103), the transmission coefficient of coupled structure (502) is as receipts, send out passage and carry out the foundation that timing calculates.

4. the bearing calibration of intelligent antenna subsystem according to claim 2, it is characterized in that: described second step 2 in (72)) comprising: up correct detection signal source (353) to a known features signal spread-spectrum to 3.84MHz, scrambling is modulated at the signal of the definite level of output on the given working carrier frequency through modulator (352), through up radiofrequency signal switch (351), up coupling cable (301,302,312), coupler component (102) is injected into the collection of letters passage (337 in the up collection of letters array (104B) that is corrected, 338,348) a certain passage, multi-user digital signal behind this up collection of letters channel response that is corrected is by Interface for digital communication (283,284,294) enter baseband digital signal switch (354) gating and enter up detection signal separator (355), from multi-user's composite signal, isolate known features signal and sampling in up correction weights generator (356) behind this up collection of letters channel response, store, successively 12 up collection of letters passages are finished above-mentioned testing process.

5. the bearing calibration of intelligent antenna subsystem according to claim 2, it is characterized in that: described second step 3 in (72)) comprising: with the known features signal behind some collection of letters channel responses is benchmark, the known features signal behind each channel response of collecting mail in up correction weights generator (356), adopt algorithm draw the passage of respectively collecting mail (337,338 ..., 348) the correction weights of error.

6. the bearing calibration of intelligent antenna subsystem according to claim 2, it is characterized in that: described second step 4 in (72)) comprising: utilize the correction weights of the passage of respectively collecting mail to remove to revise the modulation signal of up correct detection signal source (353), and repeat above-mentioned error detection procedure, after verify error correction weights are correct, changed for the 4th step (74) over to.

7. the bearing calibration of intelligent antenna subsystem according to claim 2, it is characterized in that: described the 3rd step 2 in (73)) comprising: descending correct detection signal source (255) to a known features signal spread-spectrum to 3.84MHz, be sent to downlink wave beam by Interface for digital communication (281) after the scrambling and form elder generation and the merging of other subscriber signal in the device (105A), the passage (237 of posting a letter in the array of posting a letter (104A) through being corrected again, 238,248) a certain channel modulation is on given working carrier frequency, the signal of output is by coupler component (102), feeder cable (101) is to aerial array (100), be corrected the passage of posting a letter simultaneously and contain the multiple user signals of correct detection signal by descending coupling cable (261,262,272), downlink radio-frequency signal switch (251) is to demodulator (252), multi-user digital signal after demodulator (252) response enters descending detection signal separator (253), from multi-user's composite signal, isolate the known features signal and offer sampling in the descending correction weights generator (254), store, successively 12 descending passages of posting a letter are finished above-mentioned testing process.

8. the bearing calibration of intelligent antenna subsystem according to claim 2, it is characterized in that: described the 3rd step 3 in (73)) comprising: with the known features signal behind some channel responses of posting a letter is benchmark, behind the channel response of respectively posting a letter the known features signal in descending correction weights generator (254), adopt algorithm draw the passage of respectively posting a letter (237,238 ..., 248) the correction weights of error.

9. according to the bearing calibration of claims 2 described intelligent antenna subsystems, it is characterized in that: described the 3rd step 4 in (73)) comprising: utilize the correction weights of the passage of respectively posting a letter to remove to revise the modulation signal of descending correct detection signal source (255), proofread and correct weights up to verify error and changed for the 4th step (74) over to after correct.

10. according to the bearing calibration of claims 2 described intelligent antenna subsystems, it is characterized in that: described the 4th the step (74) comprising: with the up passage of respectively collecting mail (337,338 ..., 348) the correction weights of error send into uplink beam by Interface for digital communication (282) and form device (105B) and the weighting in the lump of other weight coefficient, discharge the scrambler of application, once up correction finishes; With the descending passage of respectively posting a letter (237,238 ..., 248) the correction weights of error send into downlink wave beam by Interface for digital communication (280) and form device (105A) and the weighting in the lump of other weight coefficient, discharge the spreading code of application, once descending correction finishes.

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