JP2000151255A - Method and system for calibrating antenna array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for calibrating a transmitter and/or a receiver while an antenna array is in use by coding a calibration signal so as to be substantially orthogonal to a communication traffic signal with a coding procedure, extracting the injected calibration signal and calibrating part of a circuit of the transmitter and/or the receiver on the basis of the extracted calibration signal. SOLUTION: A calibration signal generator 107 outputs a calibration signal that is coded so as to be substantially orthogonal to a communication traffic signal in compliance with a prescribed coding procedure to a divider 110 via a line 108, The divider 110 applies the calibration signal to a directional coupler 100 connected to a transmission line 23 through which a signal from a reception antenna array is applied to a down converter 18. Then the calibration signal is extracted and a configuration section of the transmitter and/or the receiver can be calibrated on the basis of the calibration signal. According to this method, since the usual operation of the antenna array is substantially not affected, the transmission/reception of the communication traffic signal can be continued without being interrupted even during the calibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the calibration of an antenna array and an electronic circuit associated with the antenna array. The present invention relates to mobile communication, in particular, CDMA (Code Division Multiple Access:
It is suitable for application to a code division multiplexing multiple access system, but is of course not limited to these applications.

[0002]

2. Description of the Related Art It is well known that an antenna array capable of individually controlling a plurality of array elements has various advantages over a single antenna. For example, in mobile communication, a plurality of signals can be transmitted to a specific mobile to improve the gain. Commercially available systems using antenna arrays with multiple antenna elements connected to individual receivers and transmitters are known.

Problems known to those skilled in the art of such antenna arrays include individual tolerances due to manufacturing tolerances, cable length differences, and differences in the characteristics of the active electronic components of the transmitter and receiver. This means that "variation" occurs in phase shift or gain between elements. That is, even if a single identical signal is supplied to all transmitters, the signals emitted from the corresponding antennas may differ in amplitude and / or phase, respectively. Similarly, even when a plurality of identical signals are received by all the antennas constituting the array, there is a problem that the signal output of the receiver is not the same in amplitude and / or phase.

[0004] To solve the above problems, it is known, for example, to store a calibration vector having a series of complex multiplication factors and determining the characteristics of the antenna array and its associated electronic elements. This calibration vector is, for example, However, determination of such properties often requires complex calibration equipment, and basic calibration is usually performed only once during array installation or manufacturing. In addition, the class calibration vector
vector) is often applied only to special types of devices.

[0005] For this reason, conventionally, there have been several proposals for performing calibration of a phased array by passing a calibration signal instead of a normal signal, and an example thereof is disclosed in WO-95 / 34103, for example. However, these conventional examples have a problem that they are not suitable for performing calibration without interrupting communication in an operating communication system.

Further, it has been proposed to calibrate an antenna array using a calibration device provided at a remote place.
For example, US Pat. No. 5,546,090 discloses a transponder for use in calibrating an antenna array,
This transponder receives the signal transmitted from the antenna array and returns the received signal to the antenna array, so the calibration equipment is directly connected to the array, and the transponder itself is relatively simple in configuration and movable It is. However, even if the transponder is a device having a simple configuration, the use of an antenna provided at a remote location for calibration complicates the calibration operation and makes it difficult to perform periodic calibration. There is.

Further, European Patent Application EP-A-7
13261 discloses an antenna array calibration device for satellite communications and is "small" (low power and limited bandwidth)
The probe signal is transmitted so as not to cause unacceptable interference with other signals. The use of low-power probe signals complicates the measurement (there is a statement that a dedicated remote calibration station is required), and has the problem that the measurement takes a long time.

Further, British Patent Application Publication GB-A-23
No. 13523 is particularly applicable to GSM (Global System for Mobi).
Le communication) discloses a system for calibrating an error correction and calibration circuit by injecting a low-power wideband signal into an error correction circuit. The above error correction circuit is provided via a directional coupler, and is therefore separated from the main transmitter / receiver circuit. The technology disclosed in this UK patent application is:
It is only about calibrating the built-in (built-in) calibration circuit and does not address the basic calibration problem of the receiver or transmitter circuit that processes signals during uplink or downlink communication. Note that there is no.

[0009]

Therefore, in particular, CDMA
It would be desirable to implement a system and means (technique) to calibrate the "in service" of the transmitter and / or receiver used for actual transmission and reception for the higher frequencies used in this system. I can understand that. Note that this technique allows more frequent and reliable calibration.

Accordingly, it is an object of the present invention to provide a method and apparatus suitable for in-service calibration of an antenna array, ie, calibration performed during use of the antenna array.

It is another object of the present invention to provide a calibration method and apparatus which do not require a calibration apparatus or a transponder provided separately from the apparatus provided with the antenna array.

[0012]

According to a first calibration method of the present invention, a transmitter or a receiver connected to an antenna array element and "exchanging" a plurality of communication traffic signals with the antenna array element. A method of calibrating at least a portion of a component, wherein the plurality of communication traffic signals are encoded according to a certain encoding procedure or scheme so as to be substantially orthogonal to each other. Providing a calibration signal to a component of the transmitter or receiver, wherein the calibration signal is coded substantially orthogonal to the communication traffic signal according to the fixed coding procedure (ie, the fixed Supplies a calibration signal encoded substantially orthogonal to the communication traffic signal according to the encoding procedure of (1) to a component of the transmitter or the receiver). Taking out the supplied calibration signal,
A method of calibrating a component of the transmitter or the receiver based on the extracted signal.

Thus, the normal operation of the antenna array is substantially unaffected by the calibration, so that transmission and reception of communication traffic signals can continue substantially uninterrupted during the calibration operation. That is, the above-described method according to the present invention has an advantage that an operating transmitter or receiver can be calibrated regularly or continuously without interrupting the use of the antenna array. Further, according to the above-described method of the present invention, since the calibration signal can be processed by the circuit to be calibrated almost in the same manner as the communication traffic, the calibration signal receives substantially the same phase deterioration and amplitude deterioration as the communication traffic signal. become. For this reason, calibration can be performed more accurately.

In the above-mentioned conventional example, since the calibration signal has a different property from a normal communication signal (for example, the calibration signal has lower power, a narrower bandwidth, and a different frequency than the normal communication signal), It can be seen that the calibration signal undergoes different phase or amplitude degradation, especially due to non-linear elements in the receiver and transmitter, resulting in inaccurate calibration.

Note that a plurality of signals being substantially orthogonal to each other means that these signals do not substantially interfere with each other.

A first calibration device according to the present invention is a transmitter or a receiver of a communication device connected to an antenna array element for "exchanging" a plurality of communication traffic signals with the antenna array element. An apparatus for calibrating at least a part of a component, wherein the plurality of communication traffic signals are encoded according to a predetermined encoding procedure so as to be substantially orthogonal to each other, and the apparatus transmits the calibration signal to the transmission traffic signal. Means for supplying the calibration signal to the communication traffic signal substantially orthogonal to the communication traffic signal according to the constant encoding procedure, the apparatus further comprising: Means for extracting the supplied calibration signal, and based on the extracted signal, at least one means for use in a component of the transmitter or receiver. And means for determining a positive parameter.

On the other hand, a second calibration device according to the present invention is a communication device connected to an antenna array having a plurality of elements, the device having a plurality of transmitters and receivers, and A receiver and a receiver are provided for connecting to respective elements of the antenna array and for "exchanging" communication traffic signals with the antenna array elements, wherein the plurality of communication traffic signals are fixed such that they are substantially orthogonal to one another. Encoded according to an encoding procedure, the device further comprising:
Means for supplying a calibration signal to a component of the transmitter or receiver, wherein the calibration signal is encoded substantially orthogonal to the communication traffic signal according to the constant encoding procedure, The apparatus further comprises means for extracting the supplied calibration signal, and means for determining, based on the extracted calibration signal, at least one calibration parameter used in a component of the transmitter or the receiver.

Preferably, the calibration signal is supplied locally (injected) and extracted (extracted). Providing and extracting signals locally means that a separate "device or transponder" is not used, and the calibration device should be integrated with the device to be calibrated. preferable.

The antenna array is preferably arranged to communicate over a plurality of (physically or logically) defined channels, and the calibration signal comprises one or more than one that is not used for communication traffic. Preferably it is supplied to a channel.

More preferably, the antenna array is a CDM
The calibration signal used in the A communication system is encoded with one or more spread codes different from the code assigned to the communication traffic.

In the case of a CDMA system, the calibration signal, at least for calibration at the transmitter side, comprises a plurality of orthogonal variable spreading factors (OVSFs) used for communication traffic.
Preferably, the injection is performed using one OVSF short code different from the Orthogonal Variable Spreading Factor code. By doing so, it is not necessary to use a plurality of OVSF codes for calibration, and it is possible to avoid interference with user traffic. OVS available on the downlink (downlink) side
F codes are very limited. Since a plurality of scrambling codes are used in the uplink (uplink) to identify a mobile unit, the number of restrictions is less than that in the downlink, but a combination of one OVSF code and one scrambling code is used in a receiver. It is preferably used for calibration on the side.

Since the calibration uses the same coding procedure as that used for communication traffic, the calibration hardware is similar to the coding procedure required for decoding communication signals, Therefore, design and testing can be simplified.

The present invention can be applied independently to one or both of the receiver side and the transmitter side of the antenna array.

When calibrating the (transmitter side), the short code is set to the antenna array so that the combination of the OVSF and the data sequence for each transmitter circuit is orthogonal to each other over at least one complete integration period. It is preferable to further modulate and select a data sequence that changes between elements. In this way, signals from the transmitter side circuits are combined and downconverted using a single converter without the need for a separate OVSF short code.

On the transmitter side, an individually identifiable signal is preferably supplied to each of the plurality of transmitter circuits. here,
Each of the plurality of transmitters connects to a corresponding array element, preferably substantially simultaneously. Therefore, a plurality of signals can be combined and extracted using one receiver. This makes it possible to simultaneously calibrate a plurality of elements without having to prepare a plurality of converters.

In the case of calibration of the transmitter circuit, the calibration signal is preferably injected into the digital domain (digital circuit portion) before digital-to-analog conversion. Furthermore, in the case of calibration of the transmitter side circuit, the calibration is preferably sampled via a radio frequency coupler connected to a transmission line supplying a signal to the corresponding antenna element.

When calibrating the receiver-side circuit, the calibration signal is preferably injected through a high-frequency coupler connected to a transmission line that receives a signal from a corresponding antenna element. Further, when calibrating the circuit on the receiver side, the calibration signal is preferably extracted in the digital domain after the analog-to-digital conversion of the received signal.

Signal processing can be facilitated by injecting or extracting the calibration signal in the digital domain described above.

The above-described injection and extraction of the radio frequency signal eliminates the need to provide a separate antenna which may interfere with signals transmitted and received by the antenna array or is cumbersome to install. The couplers described above are preferably provided physically close to the respective antenna elements, for example on the antenna side of a long cable, in order to minimize the variable factor between the plurality of antenna elements and the coupler. Alternatively, a separate antenna may be provided to connect a plurality of radio frequency signals to a plurality of antenna elements.

The calibration signal is injected to determine the calibration amount periodically (eg, every hour, every minute, every 10 minutes, every second) or substantially continuously. Calibrate at least about 10 times per second, about 5
If done at 0 Hz, or about 100 Hz, the phase drift of the local oscillator signal in each transmitter or receiver can be tracked.

The communication traffic signal is usually transmitted in a frame unit of 1 second or less (usually 10 ms or 20 ms). The calibration signal is output every predetermined number of frames, for example, about 1
The injection is performed every 00 frames, about every 10 frames, every frame, or every other frame. This periodic calibration signal injection occurs during normal operation and is stopped in exceptional circumstances, such as during test or maintenance periods or during periods of congested communication traffic. The plurality of frames are grouped into superframes (for example, 720 ms), and it is convenient to perform the calibration approximately every superframe.

By performing such a periodic calibration, it is possible to reliably track a small drift of the calibration due to, for example, a temperature change inside the apparatus, and to quickly find an error. Become. The present invention has an advantage that, unlike the conventional example in which the calibration cannot be performed frequently, there is almost no deterioration of the communication signal, and an overhead of a bandwidth related to the calibration can be extremely reduced. Further, the apparatus to which the present invention is applied can reduce the allowable range of calibration as a whole, thereby increasing the communicable range and increasing the user density. It also has advantages.

[0033]

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

Referring to FIG. 1, the base station for mobile communication has a signal processing circuit 10.
Are connected to the transmitter antenna array 20 via a plurality of transmission lines 21 and are also connected to the receiver antenna array 22 via a plurality of transmission lines 23. As shown, the antenna arrays 20 and 22 are physically separated, but in such a case, the antenna arrays 20 and 22
Are usually provided close to each other (although this arrangement is not necessarily absolute). Alternatively, 1
The arrays can be used for both transmission and reception, using appropriate diplexer circuits. The antenna arrays 20 and 22 perform wireless communication with a plurality of mobile terminals (voice and / or data mobile terminals) 30a, 30b and the like. The signal processing circuit 10 of the base station is connected to a telephone communication network 11 via, for example, an optical fiber, a conductor, or a microwave line.

The signal processing circuit 10 of the base station includes a baseband digital signal processing unit 12.
Processes transmission signals to the mobile unit received from the communication network 11 and processes reception signals from the mobile unit to the communication network 11.
To send to. Generally, the digital signal processing unit 12 has a beam forming network to generate a code. The output of the digital signal processing unit 12 is
The signal is input to the up-converter 16 via the analog converter 14. The up-converter 16 transmits a baseband signal (a chip rate of several MHz (for example, 4.096 MHz)) at a power and a frequency (for example, 1-
In the range of 2 GHz, it is several watts or tens of watts, and these numerical values (parameters) depend on the allocated communication band). The signal received by the antenna array 22 is amplified by a low-noise amplifier, and after being demodulated at a reduced frequency by the down converter 18,
The signal is supplied to the analog / digital converter 19 and is subjected to signal processing in the baseband / digital signal processing unit 12.

The term "up-converter" described above is used to refer to the chain circuitry of an analog transmitter having a modulator such as QPSK and a power amplifier. Similarly, the term "down converter" is used to mean a series of circuits in an analog receiver having a low noise amplifier and a demodulator.

The signal processing circuit 10 of the base station usually has a device (not shown) for correcting phase distortion and amplitude distortion by supplying a pre-programmed correction factor. This device may be provided as a network composed of a plurality of (individual) phase shifters, for example, or
Part or all of baseband digital signal processing unit 12
Or up converter 16 and down converter 1
8 may be provided integrally.

The shape of the antenna array is arbitrary. For example, the antenna array may be a linear or circular shape having an arbitrary number (usually 2 to 10) of elements, or may extend in a one-dimensional or two-dimensional direction. Good.

As described above with reference to FIG. 1, the device shown in FIG. 1 is a known device, for example, WO95 / 341.
03 or GB-A-2313523.

The present invention relates to ETSI UTRA (UMTS Terrestrial
Radio Access) standard, Japanese W standardized by ARIB
-It is preferable that the configuration is based on a CDMA system or a standard or system derived therefrom.
However, it will be appreciated that the invention is also applicable to systems based on similar criteria known to those skilled in the art.

Referring to FIG. 1, description will be given of an improved unit and / or an additional unit used for "calibration of reference station of mobile communication system" according to the present embodiment. As mentioned above, the above-described improvements are applied independently to the calibration of the transmitter side circuit, the receiver side circuit, or both.

First, the receiver side circuit will be described. As described above, the down converter 18 is connected to the transmission line 2.
3 to receive a signal from the receiving antenna array 22.
The output of down converter 18 is provided to a circuit that processes the received communication traffic signal, as before. In the present embodiment, one calibration signal (the generation of which will be described later) is injected into the radio frequency by the coupler 100 provided on each transmission line 23. In the present embodiment, one calibration signal (the generation of which will be described later) is injected into each of the plurality of transmission lines 23 in the radio frequency domain. The coupler 100 is ideally provided close to the antenna array 22. Down converter 18
Is supplied to a calibration signal processing unit 106 used for calibrating the down converter according to the present embodiment in addition to the signal output from the communication signal processing device (the details will be described later).

Next, the transmitter side circuit will be described. As described above, the up-converter 16 receives the baseband communication signal (the signal to be transmitted) from the digital signal processing unit 12. The output of the up-converter 16 is supplied to the transmission antenna array 20 via the transmission line 21. In addition to the communication signals described above, one calibration signal (the generation of which will be described later) is optimally processed in the digital domain and injected into the signals supplied to the respective up-converters 16. The output of each up converter 16 is
A part is extracted (sampled) in the radio frequency domain by the couplers 112 provided in the respective transmission lines 21. still,
The coupler 12 is ideally provided close to the antenna array 20.

The entire operation of the calibration device is performed by the calibration controller 105.
Controlled by. The calibration controller 105 generates and analyzes a calibration signal and performs other functions (processing) as described later.
Control.

Next, generation of a calibration signal will be described.
In the present embodiment, the calibration signal generator 107 outputs a single calibration signal to the divider 110 via the line 108, and the divider 110 supplies a plurality of calibration signals to the receiver-side circuit. The splitter 110 receives the reception antenna array 22
The calibration signal is supplied to each of the directional couplers 100 connected to the transmission line 23 that supplies the signal from the down converter 18 to the down converter 18. Note that, for example, it is also possible to combine the calibration signals via a plurality of external antennas provided adjacent to the elements of the antenna array.

The calibration signal is transmitted to the mobile terminal 30a during operation,
It has "dummy" data encoded using an uplink spreading code not assigned to 30b. Preferably, the spreading code has the same format as the signal that may be transmitted from the mobile terminal (although other formats can be used).
The signal transmitted from the mobile terminal is formatted as a voice signal or a data signal. Typically, the expected distortions of the voice and data signals are similar, so a single type of calibration signal must be used, but may correspond to changes in packet format. When a plurality of calibration signals to be used for calibration of a transmitter-side circuit are generated using the same calibration signal generator as in the present embodiment, the calibration signal on the receiver side is converted to the calibration signal on the transmitter side. A format similar to the signal is preferred for simplicity of design.

The calibration signal is preferably injected at as low a level as possible to prevent interference. The level required is determined by the integration time and the "signal-to-noise ratio after integration" required for accurate phase and amplitude measurements. Normally, the power level of the calibration signal should be approximately the same as the level of the signal received at the antenna array, e.g., equal to the received signal level from a single user at full cell loading. .

Next, the calibration signal on the transmitter side will be described. Calibration signal generator 107, which is the same as described above, generates a plurality of calibration signals for each transmitter circuit via line 109. These calibration signals are digitally added to the communication traffic signal to form a plurality of upconverters 16.
Supplied to The calibration signal is preferably injected at as low a level as possible to provide an adequate signal-to-noise ratio to minimize interference with communication traffic signals. The calibration signal is supplied as data encoded with a single OVSF short code, but each upconverter 16
, The calibration signals will be mutually orthogonal when integrated over a 10 ms data frame period. This data sequence is represented by an orthogonal Gold code (Orthogonal Gol
d codes). Since the orthogonal Gold codes are not completely orthogonal, it is preferable to use Walshcodes.

The inventor has devised a method for easily achieving orthogonality by extending the OVSF code tree based on the method described in section 5.3.2.2.1 of the UTRA RTT. This method is extremely useful. Therefore, assuming that c0 has a length of 256, an OVSF code calibration signal for two elements can be generated as follows. s0 = [c0 c0] s1 = [c0-c0] The above s0 and s1 are each 512 chips long, and are repeated periodically during the measurement period.

With the four elements, the following codes can be used: s0 = [c0 c0 c0 c0] s1 = [c0 c0 -c0 -c0] s2 = [c0 -c0 c0 -c0] s3 = [c0 -c0 -c0 c0] s0 to s3 Each chip length is 1024, Repeat periodically during the measurement period.

Communication channel (traffic channel)
It is preferable or possible to use longer sequences instead of repeating short sequences in order to randomize the interference that occurs in the system, and it is possible to change the sequences every frame.

The analysis of the calibration signal will be described. In the case of calibration of the receiver side circuit, the output of the down converter corresponding to the calibration signal is at the baseband level and is similar to the output corresponding to the signal received from the mobile terminal. If the device is ideally calibrated, the signals should all be in phase and amplitude. Each calibration signal is correlated with the transmitted signal to determine the phase and amplitude for the transmitted signal, and these correlation results are further correlated to obtain differences between each receiver. Typically, a similar technique is used to determine the appropriate weights to identify the source of pilot signals from mobile terminals 30a, 30b, etc. in other parts of the base station and in digital signal processor 12. Is done. The result of this analysis is used to preferentially select a signal from any mobile terminal at a particular location, and furthermore, to direct the downlink to the mobile terminal, Used to generate a user's beamforming weighting vector.

The calibration signal can be thought of as originating from a virtual mobile terminal equidistant from all antenna elements (or if the signals injected into the receiver circuit differ by some known amount). For example, it can be considered that the signal originates from another virtual mobile terminal located at a predetermined distance.) The calibration error is measured based on the apparent position of the virtual mobile terminal that is the apparent source of the calibration signal.

Following the analysis of the calibration signal, the correction factors stored for the receiver side circuits are adjusted (eg, by gradually changing them) until equal phase and amplitude are obtained from the respective down converter. Or adjust the correction factor by directly calculating the new parameter).

In the case of calibration of the up converter 16,
Obviously, the output of upconverter 16 taken (sampled) by combiner 112 is at radio frequency. The analysis of these signals is, in principle, performed directly at radio frequency, but it is more convenient to analyze them in the digital domain, as well as the circuits on the receiver side.
Of course, this requires the signal to be down-converted (converted to a lower frequency), which must be processed without introducing unknown errors. In this embodiment, the dedicated calibration signal is directly combined at radio frequency in the coupler 111 for low-frequency conversion by the down-converter 101, and the down-converter 101 adds to the signal received from another down-converter. And supplied to the calibration signal processing device 106.

If the transmission signal is appropriately attenuated and frequency-converted, an existing receiver can be used, but it is preferable to use a down converter dedicated to calibration.

By providing the coupler 111, it is only necessary to provide a single calibration down converter. Therefore, the number of circuit components can be reduced, and a combiner (combine
r) Individual down /
The need to calibrate or check the converter can be eliminated. Another advantage of combining the signals is that it allows simultaneous calibration of all upconverters. However, instead of the above configuration, a dedicated down converter may be provided for each up converter, or the output of the up converter may be continuously supplied to the input to the calibration down converter.

As described above, since the calibration signals are orthogonal to one another, the combined signals are analyzed in the digital domain to identify individual transmitter signals. Next, the individual signals are
As well as analyzing signals from different receiver circuits,
Correlations are taken to determine phase and amplitude differences.

After extracting a plurality of signals from the respective transmitter circuits, the correction factor for the transmitter-side circuit is adjusted until all the signals have the same phase and the same amplitude (or, if the phases and amplitudes of the signals are different). , Until the phase and amplitude correspond to the injected signal).

In the arrangement described above, the calibration is transparent and the effect of the calibration on communication traffic can be minimized (only the overhead associated with providing each calibration signal exists, This overhead is usually small compared to the total traffic). Therefore, it is possible to perform calibration periodically, and it is possible to accurately track or detect a small drift based on, for example, a drift in a local oscillator in an analog circuit. Further, by continuously transmitting frames having a calibration signal, continuous calibration can be effectively performed. However, adjustment of the error correction circuit usually takes time until the effect is achieved (when error correction is performed digitally, error correction is performed instantaneously), and calibration is performed only every other frame. It is generally desirable to do so, or to send the calibration signal only during a portion of the frame and make adjustments to the calibration in the rest of the frame.

The present invention provides a CD capable of performing an effective calibration by using a scramble code for encoding a calibration signal.
It is optimally applied to the MA system, but can also be applied to an FDM (frequency division multiple access) or TDM (time division multiple access) system.

[0062]

As mentioned above, especially with respect to CDMA systems and higher frequencies than used in these systems, the transmitter and / or receiver used for actual transmission and reception is "in service". Can be realized, and more frequent and reliable calibration can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a portion of FIG. 1 modified by applying the present invention.

FIG. 2 is a simplified diagram showing a conventional base station for mobile communication to which the present invention is applied.

[Explanation of symbols]

 12: Baseband digital signal processing device 14: Digital to analog converter 16: Up converter 18: Down converter 20: Array antenna for transmission 22: Array antenna for reception 30a, 30b: Mobile terminal 100, 112 : Coupler (coupler) 101: Calibration down converter 105: Calibration controller 106: Calibration signal processor 107: Calibration signal generator 110: Divider 111: Synthesizer

Claims (23)

[Claims] 1. A method for calibrating at least a part of a circuit of a transmitter or a receiver connected to an element of an antenna array and exchanging a plurality of communication traffic signals with the antenna array element, the method comprising: The signals are encoded by a coding procedure substantially orthogonal to each other, and a calibration signal is injected into the circuit, the calibration signal being coded by the coding procedure to be substantially orthogonal to the communication traffic signal. A method for calibrating an antenna array, comprising extracting the injected calibration signal and calibrating a part of the circuit based on the extracted calibration signal. 2. The method for calibrating a circuit of a CDMA communication system, wherein the calibration signal is transmitted with one or more spreading codes different from the code assigned to the communication traffic signal. How to calibrate the antenna array. 3. The method of claim 2, wherein the calibration signal is injected using a single orthogonal variable spreading factor (OVSF) short code. 4. The antenna according to claim 1, wherein a plurality of individually identifiable calibration signals are supplied to each of the plurality of transmitter circuits when calibrating the transmitter circuit.
Array calibration method. 5. The single short code is further modulated with different data sequences between elements of the antenna array,
5. The method according to claim 4, wherein the combination of the short code and the data sequence supplied to each transmitter circuit is orthogonal to each other. 6. An antenna according to claim 4, wherein the outputs of the plurality of transmitter circuits are combined in the radio frequency domain, and the plurality of calibration signals are derived from the combined output by a single receiver. -How to calibrate the array. 7. A method for calibrating a transmitter circuit, wherein the calibration signal is injected in a digital domain.
The method for calibrating an antenna array according to any one of the above. 8. A method for calibrating a transmitter circuit, wherein the output of the circuit is coupled to an antenna element via a transmission line, and the output of each transmitter is sampled by a coupler connected to the transmission line. The method for calibrating an antenna array according to claim 1, wherein the calibration is performed. 9. The method for calibrating a receiver circuit, wherein the calibration signal is injected through a radio frequency coupler connected to a transmission line for receiving a signal from a corresponding antenna. The method for calibrating an antenna array according to any one of the above. 10. The antenna according to claim 1, wherein the calibration signal for calibrating the receiver circuit is extracted in a digital domain. Array calibration method. 11. The antenna according to claim 1, wherein the calibration signal is encoded by a scramble code which is substantially orthogonal to a scramble code assigned to a remote device. -How to calibrate the array. 12. The mobile communication base station according to claim 1, wherein the base station is calibrated.
12. The method for calibrating an antenna array according to any one of claims 11 to 11. 13. A method according to claim 1, wherein the calibration signal is locally injected and extracted. 14. A method for calibrating an antenna array according to claim 1, wherein said calibration signal is injected to obtain calibration values periodically or substantially continuously. 15. The antenna array calibration method according to claim 14, wherein the communication traffic signal is transmitted in a frame unit of 1 second or less, and the calibration signal is injected every predetermined number of frames or every frame. . 16. An apparatus for calibrating at least a part of a circuit of a transmitter or a receiver of a communication device connected to an element of an antenna array and exchanging a plurality of communication traffic signals with the antenna array element, the apparatus comprising: The communication traffic signals are encoded by an encoding procedure so as to be substantially mutually orthogonal, and the calibration device has means for injecting a calibration signal into the circuit, and the calibration signal is encoded by the encoding procedure. Being substantially orthogonal to the communication traffic signal, the calibration device further comprises means for extracting the injected calibration signal, and at least one of: calibrating a portion of the circuit based on the extracted calibration signal. Means for determining two calibration parameters. 17. A communication device connected to an antenna array having a plurality of elements, said communication device having a plurality of transmitter circuits and a plurality of receiver circuits, each circuit being associated with said antenna array. Communicates a communication traffic signal with the antenna array element, the communication traffic signal being coded by a coding procedure so as to be substantially orthogonal to each other, and the communication device further comprises: Means for injecting a calibration signal into the circuit, wherein the calibration signal is encoded to be substantially orthogonal to the communication traffic signal according to the encoding procedure, and the communication device further comprises: A calibration device comprising: means for extracting; and means for determining at least one calibration parameter for calibrating a part of the circuit based on the extracted calibration signal. 18. Apparatus according to claim 16 or 17, arranged to inject an individually identifiable calibration signal into each of the plurality of transmitter circuits. 19. The calibration signal is encoded with an OVSF short code, wherein the calibration signal has a different data sequence between transmitter circuits, and the data sequence is therefore different from the short code and the transmitter code. 19. Apparatus according to claim 18, wherein the combinations of the data sequences supplied to each of the circuits are mutually orthogonal. 20. The apparatus according to claim 16, further comprising means for combining outputs of a plurality of transmitter circuits in a radio frequency domain, and one receiver for extracting a calibration signal from the combined output. apparatus. 21. Digital signal processing means for processing a baseband digital communication traffic signal to be received or transmitted, said digital signal processing means injecting or receiving said calibration signal into a signal to be transmitted. 21. Apparatus according to any of claims 16 to 20 for extracting the calibration signal from a signal. 22. A transmission line for connecting a receiver or a transmitter circuit to an antenna array element, wherein the transmission latitude is provided with a coupler for injecting or extracting a signal including the calibration signal in a radio frequency range. Item 22. The apparatus according to any one of Items 16 to 21. 23. The apparatus according to claim 16, wherein said calibration signal is injected at intervals or substantially continuously.