[go: up one dir, main page]

WO2009001232A1 - Method for in-system testing of communication systems - Google Patents

Method for in-system testing of communication systems Download PDF

Info

Publication number
WO2009001232A1
WO2009001232A1 PCT/IB2008/051805 IB2008051805W WO2009001232A1 WO 2009001232 A1 WO2009001232 A1 WO 2009001232A1 IB 2008051805 W IB2008051805 W IB 2008051805W WO 2009001232 A1 WO2009001232 A1 WO 2009001232A1
Authority
WO
WIPO (PCT)
Prior art keywords
test
calibration
carrying
offset
comparison
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/IB2008/051805
Other languages
French (fr)
Inventor
Gunnar Nitsche
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NXP BV
Original Assignee
NXP BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NXP BV filed Critical NXP BV
Publication of WO2009001232A1 publication Critical patent/WO2009001232A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/30—Circuits for homodyne or synchrodyne receivers

Definitions

  • the invention relates to a method for in- system testing of communication systems in which a self- calibration method is implemented.
  • Such communication systems are used, for example, in arrangements for wireless communication (WLAN).
  • WLAN wireless communication
  • self-calibration methods are used for reducing production-related tolerances during the operation of the communication system.
  • the self-calibration methods are applied when the arrangement is switched on, at regular or irregular intervals or controlled by an event, for example a channel change.
  • BIST built-in self tests
  • Modern SoCs combine both the base-band module (BB) and the radio-frequency module (RF) on one chip. Whilst during the production of these modules on a separate chip each, these can also be tested individually, this is only possible with increased expenditure when both modules are arranged on a common chip. The expenditure consists in that additional pins and/or contact areas need to be arranged on the chip in order to access the signals transmitted between the modules. This thus requires additional chip area and increases the costs. Testing the radio frequency performance represents a further problem.
  • BB base-band module
  • RF radio-frequency module
  • Receivers of such SoCs are usually constructed as arrangements without intermediate frequency.
  • the advantage of this implementation lies both in a reduction in the costs and in the power consumption. In such receivers, the radio frequency performance may deteriorate.
  • the self-calibration methods are carried out on switch-on or repeatedly at regular or irregular intervals.
  • the object of the invention thus consists in specifying a method for testing communication systems by means of which the expenditure for providing additional modules not required for operating the communication system is reduced and the production costs are thus reduced.
  • the object is achieved in a method for in-system testing of communication systems in which a self-calibration method is implemented, of the type initially mentioned, in that, controlled by a control program, the communication system is tested in such a manner that test values are determined by utilizing means for carrying out the self-calibration method, that the test values are compared with predetermined tolerance limits and that, in dependence on this comparison a statement about the operability of the chip is output.
  • the invention describes an integrated self test (BIST) for communication systems, for example wireless one-chip systems, which is carried out in the communication system itself (e.g. Chip, SoC).
  • BIST integrated self test
  • the communication system itself e.g. Chip, SoC
  • this does not require any additional external or internal hardware which is integrated on the chip only for the self-test.
  • the invention is based on the concept of evaluating information which is generated by utilizing means for carrying out self- calibration methods and, derived from these, generating a statement about the operation of the chip.
  • the means for carrying out the self-calibration methods are utilized which are utilized by the chip itself periodically or started by an event during active operation, for example after switch-on.
  • an event can be, for example, a channel change which starts a self-calibration method in order to adapt the arrangement to the changed operating and/or environmental conditions.
  • VCO voltage-controlled oscillators
  • a comparison of all minimum and maximum values with associated lower and upper tolerance limits is made and as a result of the comparison, a decision is made whether values have occurred within or outside a predetermined tolerance range during the testing of the individual channels.
  • the lower tolerance limit is usually located at a value of zero in this process. If this is reached, it would mean that the calibration values were constant for all channels, this being the best achievable value in most cases.
  • the test by the means for carrying out a method for VCO calibration, which generate a frequency corresponding to a channel is made in such a manner that the test is positive if the frequency generated by the means, which belongs to an underfrequency range, is allocated to the same underfrequency range or the next highest underfrequency range with increasing channel number.
  • the means for carrying out the VCO calibration are utilized for testing the frequencies or underfrequency ranges allocated to the channel numbers. For this purpose, for example, all adjustable channels/frequencies are tested successively, the test running, beginning with the lowest channel number, up to the highest channel number.
  • the method according to the invention performs a comparison of the test values determined with the predetermined tolerance limits.
  • a simplified form of evaluation consists in checking whether the frequency generated by the VCO also increases with increasing channel number.
  • Another variant of the test consists in testing whether the underfrequency range remains the same with increasing channel number or whether it changes to the next higher underfrequency range.
  • the number of underfrequency ranges used can be determined and compared with a predetermined value.
  • the predetermined value for the underfrequency ranges used can be ⁇ 3, which means that a maximum of three underfrequency ranges are allowed to be passed during the test. If this is the case, the test is positive.
  • the test by the means for carrying out a method for Rx DC calibration by means of which a Rx DC offset is determined with a defined input signal of an amplifier with adjustable gain, is made in such a manner that the test is positive when the Rx DC offset indicates a change when the means are used for coarse calibration.
  • the test is made in such a manner that a characteristic, which maps a dependence of an Rx DC offset determined on an adjustable Rx DC compensation value, is compared with a predetermined tolerance range.
  • both the steepness of the characteristic and a tolerance range within which the characteristic is to extend can be predetermined.
  • the test by the means for carrying out a method for Rx DC calibration by means of which a Rx DC offset is determined with a defined input signal of an amplifier with adjustable gain, is made in such a manner that the test is positive when the Rx DC offset generates a Rx DC offset within the tolerance limits when the means are used for fine calibration.
  • the means for carrying out the method for Rx DC calibration are utilized in such a manner that with a defined input signal at the input of the amplifier, at all possible adjustable gains of the amplifier, the respective associated output signal is measured and stored as test value when the means are utilized according to the invention.
  • Such amplifier arrangements usually have two possibilities for calibration, coarse calibration and fine calibration.
  • the invention evaluates the test values generated by the means for fine calibration, in such a manner that a comparison with a predetermined tolerance value or a tolerance range is made. If the test value lies within the tolerance range, the test is positive. Otherwise, there is a fault in the subassembly of the chip since the test specifications are not achieved.
  • the invention evaluates the test values generated by the means for coarse calibration in such a manner that a change in coarse calibration must also result in a change of the magnitude of the test value. If the magnitude of the test value does not change or only to an extent which is too small, there is a fault in the module. This can lie in a missing connection between the base band module and the radio -frequency module.
  • the input signal is zero.
  • the defined input signal of the amplifier, used during the Rx DC calibration can have, for example, a value of zero volts.
  • test is made by the means for carrying out the method for Tx LO leakage.
  • test is made by the means for carrying out the method for Tx IQ calibration.
  • the operation of the method according to the invention is described by way of example of a fundamental self test.
  • the minimum and the maximum is determined over the channels.
  • test is "in order" precisely when all individual tests were “in order”.
  • the in-system test of the one-chip system is evaluated as positive, for example, only when all individual tests or test steps have arrived at a positive result.
  • all tolerance ranges within the communication system are checked and only the overall test result is transmitted to an external arrangement. The test can thus be carried out very rapidly.
  • all minimum and maximum values of the individual calibrations are transferred to an external arrangement which carries out the checking with the tolerance range limits. This supports the possibility of acquiring statistics of the individual test steps which can be utilized for optimizing the tolerance range limits.
  • the calibration values are only slightly dependent on the corresponding channel.
  • narrower tolerance ranges can be utilized, for example, for the difference between maximum value and minimum value.
  • the BIST can be combined with a traditional production test which requires external test arrangements.
  • the BIST should be carried out first so that chips which have been determined as "defective" during the performance of the BIST can be eliminated early. In this case, the more time-consuming external test is then not required. This combination thus reduces the mean testing time for the chips.
  • the BIST cannot only be used for a production test but also for the purpose of fault finding. Since no external supplementary hardware is required, the test can be carried out at any time, even in the final product in active operation.
  • the present invention can be applied in all communication systems for wireless radio, for example for wireless LAN which need to be calibrated.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

The invention, which relates to a method for in-system testing of communication systems in which a self-calibration method is implemented, is based on the object of specifying a method by means of which the expenditure for providing additional modules not required for operating the chips is reduced. This object is achieved by the fact that, controlled by a control program, the communication system is tested in such a manner that test values are determined by utilizing means for carrying out the self-calibration method, that the test values are compared with predetermined tolerance limits and that, in dependence on this comparison, a statement about the operability of the chip is output.

Description

DESCRIPTION
METHOD FOR IN-SYSTEM TESTING OF COMMUNICATION SYSTEMS
The invention relates to a method for in- system testing of communication systems in which a self- calibration method is implemented.
Such communication systems are used, for example, in arrangements for wireless communication (WLAN). In these systems, self-calibration methods are used for reducing production-related tolerances during the operation of the communication system. In this context, the self-calibration methods are applied when the arrangement is switched on, at regular or irregular intervals or controlled by an event, for example a channel change.
The complexity of communication systems (e.g. a one-chip systems/system on chip/SoC) continuously increases. In consequence, both the testing complexity of these chips and the production costs rise.
During the production of the chips, so-called built-in self tests (BIST) are used for reducing the production costs and increasing the yield. In a BIST, for example, test signals are generated and evaluated by a test circuit additionally integrated on the chip. Such tests can take place during the production cycle or also in the operating state of the arrangement and enable malfunctions to be detected.
Modern SoCs combine both the base-band module (BB) and the radio-frequency module (RF) on one chip. Whilst during the production of these modules on a separate chip each, these can also be tested individually, this is only possible with increased expenditure when both modules are arranged on a common chip. The expenditure consists in that additional pins and/or contact areas need to be arranged on the chip in order to access the signals transmitted between the modules. This thus requires additional chip area and increases the costs. Testing the radio frequency performance represents a further problem.
Receivers of such SoCs are usually constructed as arrangements without intermediate frequency. The advantage of this implementation lies both in a reduction in the costs and in the power consumption. In such receivers, the radio frequency performance may deteriorate.
The reasons for this are, for example, losses in the local oscillator (LO leakage), a direct voltage shift (DC offset) and inequalities between the imaginary and the real component (IQ imbalance).
These impairments of the radio frequency performance are reduced by so-called self-calibration methods in the operating state of the receiver. The self-calibration methods are carried out on switch-on or repeatedly at regular or irregular intervals.
From US 2006/0020865, a BIST for testing analogue circuit functions is known in which, for example, the frequency response, the gain, the cut-off frequency, the signal/noise ratio and the linearity are measured. The disadvantage of this prior art consists in that additional supplementary hardware not required for operating the circuit must be provided for carrying out the BIST.
The object of the invention thus consists in specifying a method for testing communication systems by means of which the expenditure for providing additional modules not required for operating the communication system is reduced and the production costs are thus reduced.
According to the invention, the object is achieved in a method for in-system testing of communication systems in which a self-calibration method is implemented, of the type initially mentioned, in that, controlled by a control program, the communication system is tested in such a manner that test values are determined by utilizing means for carrying out the self-calibration method, that the test values are compared with predetermined tolerance limits and that, in dependence on this comparison a statement about the operability of the chip is output.
The invention describes an integrated self test (BIST) for communication systems, for example wireless one-chip systems, which is carried out in the communication system itself (e.g. Chip, SoC). In contrast to the prior art, this does not require any additional external or internal hardware which is integrated on the chip only for the self-test.
The invention is based on the concept of evaluating information which is generated by utilizing means for carrying out self- calibration methods and, derived from these, generating a statement about the operation of the chip. During this process, the means for carrying out the self-calibration methods are utilized which are utilized by the chip itself periodically or started by an event during active operation, for example after switch-on. Such an event can be, for example, a channel change which starts a self-calibration method in order to adapt the arrangement to the changed operating and/or environmental conditions.
Conventional self-calibration methods for such receiver arrangements without intermediate frequency are, for example, the calibration of voltage-controlled oscillators (VCO), in which the optimum of a VCO underfrequency range is found, the Rx DC offset calibration, the Tx LO leakage and the Tx IQ calibration.
Depending on the respective implementation, for example of a receiver, further self-calibration methods may be necessary which are also utilized in the self-test of the chip.
In one embodiment of the invention, it is provided that a comparison of all minimum and maximum values with associated lower and upper tolerance limits is made and as a result of the comparison, a decision is made whether values have occurred within or outside a predetermined tolerance range during the testing of the individual channels.
In this test, it is sufficient to compare the minimum value with the lower tolerance range limit and/or the maximum value with the upper tolerance range limit.
In a further embodiment of the invention, it is provided that a comparison of all differences between maximum value and minimum value with associated lower and upper tolerance limits is made and as a result of the comparison, a decision is made whether the values lie within a predetermined tolerance range.
The lower tolerance limit is usually located at a value of zero in this process. If this is reached, it would mean that the calibration values were constant for all channels, this being the best achievable value in most cases.
In a particular embodiment of the invention, it is provided that the test by the means for carrying out a method for VCO calibration, which generate a frequency corresponding to a channel, is made in such a manner that the test is positive if the frequency generated by the means, which belongs to an underfrequency range, is allocated to the same underfrequency range or the next highest underfrequency range with increasing channel number.
The means for carrying out the VCO calibration are utilized for testing the frequencies or underfrequency ranges allocated to the channel numbers. For this purpose, for example, all adjustable channels/frequencies are tested successively, the test running, beginning with the lowest channel number, up to the highest channel number. The method according to the invention performs a comparison of the test values determined with the predetermined tolerance limits. A simplified form of evaluation consists in checking whether the frequency generated by the VCO also increases with increasing channel number. Another variant of the test consists in testing whether the underfrequency range remains the same with increasing channel number or whether it changes to the next higher underfrequency range. In addition, the number of underfrequency ranges used can be determined and compared with a predetermined value. For example, the predetermined value for the underfrequency ranges used can be < 3, which means that a maximum of three underfrequency ranges are allowed to be passed during the test. If this is the case, the test is positive.
In a further embodiment of the invention, it is provided that the test by the means for carrying out a method for Rx DC calibration, by means of which a Rx DC offset is determined with a defined input signal of an amplifier with adjustable gain, is made in such a manner that the test is positive when the Rx DC offset indicates a change when the means are used for coarse calibration.
In a variant of the embodiment of the invention it is provided that the test is made in such a manner that a characteristic, which maps a dependence of an Rx DC offset determined on an adjustable Rx DC compensation value, is compared with a predetermined tolerance range.
In this test, both the steepness of the characteristic and a tolerance range within which the characteristic is to extend can be predetermined.
In another embodiment of the invention, it is provided that the test by the means for carrying out a method for Rx DC calibration, by means of which a Rx DC offset is determined with a defined input signal of an amplifier with adjustable gain, is made in such a manner that the test is positive when the Rx DC offset generates a Rx DC offset within the tolerance limits when the means are used for fine calibration.
The means for carrying out the method for Rx DC calibration are utilized in such a manner that with a defined input signal at the input of the amplifier, at all possible adjustable gains of the amplifier, the respective associated output signal is measured and stored as test value when the means are utilized according to the invention.
Such amplifier arrangements usually have two possibilities for calibration, coarse calibration and fine calibration.
The invention evaluates the test values generated by the means for fine calibration, in such a manner that a comparison with a predetermined tolerance value or a tolerance range is made. If the test value lies within the tolerance range, the test is positive. Otherwise, there is a fault in the subassembly of the chip since the test specifications are not achieved.
The invention evaluates the test values generated by the means for coarse calibration in such a manner that a change in coarse calibration must also result in a change of the magnitude of the test value. If the magnitude of the test value does not change or only to an extent which is too small, there is a fault in the module. This can lie in a missing connection between the base band module and the radio -frequency module.
In one embodiment of the invention, it is provided that the input signal is zero.
The defined input signal of the amplifier, used during the Rx DC calibration, can have, for example, a value of zero volts.
In a special embodiment of the invention, it is provided that the test is made by the means for carrying out the method for Tx LO leakage.
In a further embodiment of the invention, it is provided that the test is made by the means for carrying out the method for Tx IQ calibration. In the text which follows, the operation of the method according to the invention is described by way of example of a fundamental self test.
In this self test, all channels are adjusted and all required calibrations are carried out for each channel.
For each calibration value, the minimum and the maximum is determined over the channels.
Comparison of all minimum and maximum values with the associated lower and upper limit values and decision about whether values have occurred within or outside the predetermined tolerance range during the self test of the individual channels.
Comparison of all differences between maximum value and minimum value with associated lower and upper range limits and decision about whether the values lie within the tolerance range.
Storage of all test results and determination of the overall test result. In this connection, the test is "in order" precisely when all individual tests were "in order".
According to the invention, the in-system test of the one-chip system is evaluated as positive, for example, only when all individual tests or test steps have arrived at a positive result.
In one embodiment of the invention, all tolerance ranges within the communication system are checked and only the overall test result is transmitted to an external arrangement. The test can thus be carried out very rapidly.
In another embodiment of the invention, all minimum and maximum values of the individual calibrations are transferred to an external arrangement which carries out the checking with the tolerance range limits. This supports the possibility of acquiring statistics of the individual test steps which can be utilized for optimizing the tolerance range limits.
Usually, the calibration values are only slightly dependent on the corresponding channel. Thus, narrower tolerance ranges can be utilized, for example, for the difference between maximum value and minimum value.
To improve the testing range, the BIST can be combined with a traditional production test which requires external test arrangements. In such a combination, the BIST should be carried out first so that chips which have been determined as "defective" during the performance of the BIST can be eliminated early. In this case, the more time-consuming external test is then not required. This combination thus reduces the mean testing time for the chips.
The BIST cannot only be used for a production test but also for the purpose of fault finding. Since no external supplementary hardware is required, the test can be carried out at any time, even in the final product in active operation.
In principle, the present invention can be applied in all communication systems for wireless radio, for example for wireless LAN which need to be calibrated.

Claims

1. Method for in- system testing of communication systems in which a self-calibration method is implemented, characterized in that, controlled by a control program, the communication system is tested in such a manner that test values are determined by utilizing means for carrying out the self-calibration method, that the test values are compared with predetermined tolerance limits and that, in dependence on this comparison, a statement about the operability of the chip is output.
2. Method according to Claim 1, characterized in that a comparison of all minimum and maximum values with associated lower and upper tolerance limits is made and as a result of the comparison, a decision is made whether values have occurred within or outside a predetermined tolerance range during the test of the individual channels.
3. Method according to Claim 1, characterized in that a comparison of all differences between maximum and minimum value with associated lower and upper tolerance limits is made and as a result of the comparison, a decision is made whether the values lie within a predetermined tolerance range.
4. Method according to one of Claims 1 to 3, characterized in that the test by the means for carrying out a method for VCO calibration, which generate a frequency corresponding to a channel, is made in such a manner that the test is positive if the frequency generated by the means, which belongs to an underfrequency range, is allocated to the same underfrequency range or the next-highest underfrequency range with increasing channel number.
5. Method according to one of Claims 1 to 3, characterized in that the test by the means for carrying out a method for Rx DC calibration, by means of which a Rx DC offset is determined with a defined input signal of an amplifier with adjustable gain, is made in such a manner that the test is positive when the Rx DC offset indicates a change when the means are used for coarse calibration.
6. Method according to Claim 5, characterized in that the test is made in such a manner that a characteristic, which maps a dependence of a RxDC offset determined on an adjustable RxDC compensation value, is compared with a predetermined tolerance range.
7. Method according to one of Claims 1 to 3, characterized in that the test by the means for carrying out a method for Rx DC calibration, by means of which a Rx
DC offset is determined with a defined input signal of an amplifier with adjustable gain, is made in such a manner that the test is positive when the Rx DC offset generates a Rx DC offset within the tolerance limits when the means are used for fine calibration.
8. Method according to Claim 5 or 7, characterized in that the input signal is zero.
9. Method according to one of Claims 1 to 3, characterized in that the test is made by the means for carrying out the method for Tx LO leakage.
10. Method according to one of Claims 1 to 3, characterized in that the test is made by the means for carrying out the method for Tx IQ calibration.
PCT/IB2008/051805 2007-06-22 2008-05-08 Method for in-system testing of communication systems Ceased WO2009001232A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP07110822 2007-06-22
EP07110822.9 2007-06-22

Publications (1)

Publication Number Publication Date
WO2009001232A1 true WO2009001232A1 (en) 2008-12-31

Family

ID=39760007

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2008/051805 Ceased WO2009001232A1 (en) 2007-06-22 2008-05-08 Method for in-system testing of communication systems

Country Status (1)

Country Link
WO (1) WO2009001232A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006044372A2 (en) * 2004-10-12 2006-04-27 Maxlinear, Inc. A receiver architecture with digitally generated intermediate frequency
US20060205374A1 (en) * 1999-10-21 2006-09-14 Hooman Darabi Adaptive radio transceiver with a local oscillator
WO2007039516A1 (en) * 2005-10-04 2007-04-12 International Business Machines Corporation Apparatus and method for automatically self-calibrating a duty cycle circuit for maximum chip performance

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060205374A1 (en) * 1999-10-21 2006-09-14 Hooman Darabi Adaptive radio transceiver with a local oscillator
WO2006044372A2 (en) * 2004-10-12 2006-04-27 Maxlinear, Inc. A receiver architecture with digitally generated intermediate frequency
WO2007039516A1 (en) * 2005-10-04 2007-04-12 International Business Machines Corporation Apparatus and method for automatically self-calibrating a duty cycle circuit for maximum chip performance

Similar Documents

Publication Publication Date Title
US9136899B2 (en) Built in self test and method for RF transceiver systems
US10605856B2 (en) System and method for testing a radio frequency integrated circuit having an RF circuit and an on-chip test circuit
US7958408B2 (en) On-chip receiver sensitivity test mechanism
US10278084B2 (en) RF receiver with built-in self-test function
US8774874B2 (en) Reducing power consumption by in-circuit measurement of receive band attenuation and/or noise
US8634793B2 (en) IP2 calibration measurement and signal generation
KR101781998B1 (en) Low―noise amplifier matching
US9948347B2 (en) Calibrating a transceiver circuit
US20110218755A1 (en) Integrated circuit and test method therefor
JP2005507598A (en) Tunable filter
US9876517B2 (en) RF receiver and digitally-assisted calibration method applicable thereto
US8160533B2 (en) Self-calibrating mixer
US20040198298A1 (en) Electronically tuned agile integrated bandpass filter
US9344130B2 (en) Leakage calibration for a frequency converter
US20100167674A1 (en) Integrated circuit, wireless communication unit and method for determining quadrature imbalance
WO2009001232A1 (en) Method for in-system testing of communication systems
EP4064575B1 (en) Radio frequency receiving link and radio frequency transceiving device
CN102469055A (en) Direct current drifting calibration method and device for zero-intermediate frequency receiver
Webster et al. Structural verification of a WLAN system using Built-in Self Tests

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08751161

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08751161

Country of ref document: EP

Kind code of ref document: A1