Patent US2144881A successfully refreshed from Google Patents.
Patent US5521904A successfully refreshed from Google Patents.
US5521904A
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US
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Method and apparatus for testing a base station in a time division multiple access radio communications system
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1993-12-07
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Granted: 1996-05-28
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Expires: 2013-12-07
Abstract
Abstract In a base station of a mobile cellular telephone system of the type having time division multiple access (TDMA) channels, a radio frequency test loop is established between a predetermined downlink channel of a base station transmitter and a predetermined uplink channel of a base station receiver. The test loop is in real time, thereby eliminating the time offset of the radio channels used for communications. The radio frequency test loop includes a circuit for transposing the frequency of the carrier signal from the transmitter to a frequency that can be received by the receiver. The signal having the transposed frequency is used in tests for determining values such as bit error rate (BER), transmission signal level, or reception sensitivity.
Inventors
- 👤 Mats E. Eriksson
- 👤 Hans L. Rinnback
- 👤 Hakan O. Djuphammar
- 👤 Olov T. Edler
- 👤 Sven E. Nilsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:51
CPC Classifications
H; H04; H04W; H04W24/00
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
162 words
A method for testing a base station of a time division multiple access radio communications system of the type having carrier signals divided into a plurality of frames and time slots for uplink and downlink communications, the uplink and downlink time slots having a time offset therebetween during a non-test mode, comprising the steps of: establishing a loop between a predetermined downlink time slot and a predetermined uplink time slot during a test mode, the predetermined downlink time slot and the predetermined uplink being simultaneous in time only during the test mode; transmitting a signal from a transmitter of the base station during the predetermined downlink time slot, the signal from the transmitter being a test stimuli; transposing the frequency of the signal from the transmitter to a frequency that is receivable by a receiver of the base station during the predetermined uplink time slot; and performing a test with the signal having the transposed frequency that is received by the receiver.
Claim 2
Independent Claim
162 words
A method for testing a base station of a time division multiple access radio communications system of the type having carrier signals divided into a plurality of frames and time slots for uplink and downlink communications, the uplink and downlink time slots having a time offset therebetween during a non-test mode, comprising the steps of: establishing a loop between a predetermined downlink time slot and a predetermined uplink time slot during a test mode, the predetermined downlink time slot and the predetermined uplink being simultaneous in time only during the test mode; transmitting a signal from a transmitter of the base station during the predetermined downlink time slot, the signal from the transmitter being a test stimuli; transposing the frequency of the signal from the transmitter to a frequency that is receivable by a receiver of the base station during the predetermined uplink time slot; and performing a test with the signal having the transposed frequency that is received by the receiver.
Claim 3
Dependent Claim
66 words
A method according to claim 1 wherein the transposing step includes mixing the signal from the transmitter with a signal having a first predetermined frequency in order to generate a signal having an intermediate frequency, variably attenuating the intermediate frequency signal, and mixing the attenuated intermediate frequency signal with a signal having a second predetermined frequency in order to generate the signal receivable by the receiver.
Claim 4
Dependent Claim
14 words
A method according to claim 1 wherein the test stimuli corresponds to normal traffic.
Claim 5
Dependent Claim
15 words
A method according to claim 1 wherein the test stimuli corresponds to a prestored pattern.
Claim 6
Dependent Claim
37 words
A method according to claim 1 wherein the signal from the transmitter is a frequency hopping signal and the transposing step is performed in accordance with an algorithm which matches the frequency hopping scheme of the signal.
Claim 7
Dependent Claim
30 words
A method according to claim 1 wherein the signal from the transmitter has a downlink frequency hopping scheme which is different from an uplink frequency hopping scheme of the receiver.
Claim 8
Dependent Claim
39 words
A method according to claim 1 wherein the signal from the transmitter is a time slot hopping signal and the transposing step is performed in accordance with an algorithm which matches the time slot hopping scheme of the signal.
Claim 9
Dependent Claim
19 words
A method according to claim 1 wherein the signal from the transmitter is transmitted to the receiver via couplers.
Claim 10
Dependent Claim
19 words
A method according to claim 1 wherein the signal from the transmitter is transmitted to the receiver via antennas.
Claim 11
Dependent Claim
36 words
A method according to claim 1 wherein the base station includes processing means that causes the automatic set up of the loop between the downlink time slot and the uplink time slot depending upon traffic density.
Claim 12
Dependent Claim
48 words
A method according to claim 1 wherein when it is decided that a loop is to be connected for test purposes, a switching step is performed to cause the predetermined downlink time slot to be looped with the predetermined uplink time slot, leaving the other time slots unaffected.
Claim 13
Dependent Claim
18 words
A method according to claim 1 wherein the loop is capable of adapting to different downlink power levels.
Claim 14
Dependent Claim
35 words
A method according to claim 1 wherein the predetermined downlink time slot is automatically linked to the predetermined uplink time slot when the predetermined downlink is active and the predetermined uplink time slot is idle.
Claim 15
Dependent Claim
43 words
A method according to claim 1 wherein before and after the step of performing a test, a check of the background interference level is performed in order to get a picture of the test interference level generated by other cells in the system.
Claim 16
Dependent Claim
23 words
A method according to claim 1 wherein the performing of a test includes a power measurement of the signal transmitted from the transmitter.
Claim 17
Dependent Claim
24 words
A method according to claim 1 which further includes a calibration of a received signal strength indication of the signal transmitted from the transmitter.
Claim 18
Dependent Claim
20 words
A method according to claim 1 which further includes a return loss calculation of the signal transmitted from the transmitter.
Claim 19
Dependent Claim
21 words
A method according to claim 1 which further includes a bit error rate determination of the signal transmitted from the transmitter.
Claim 20
Dependent Claim
19 words
A method according to claim 1 wherein the performing of a test includes a determination of signal transmission level.
Claim 21
Dependent Claim
18 words
A method according to claim 1 wherein the performing of a test includes a determination of reception sensitivity.
Claim 22
Dependent Claim
194 words
A radio frequency test loop apparatus for testing a base station of a time division multiple access radio communications system of the type having carrier signals divided into a plurality of frames and time slots for uplink and downlink communications, the uplink and downlink time slots having a time offset therebetween during a non-test mode, the base station including at least one transmitter and receiver, comprising: means for directionally coupling an-output signal of the transmitter during a predetermined downlink time slot, the output signal of the transmitter being a test stimuli; a test loop circuit, coupled to the directional coupling means, for transposing the frequency of the output signal from the transmitter to a frequency capable of being received by the receiver of the base station during a predetermined uplink time slot; and means for coupling the output of the test loop circuit to the receiver, such that the predetermined downlink time slot and the predetermined uplink time slot are looped; wherein the predetermined downlink time slot and the predetermined uplink time slot are simultaneous in time only during a test mode, and a test is performed using the signal having the transposed frequency.
Claim 23
Dependent Claim
194 words
A radio frequency test loop apparatus for testing a base station of a time division multiple access radio communications system of the type having carrier signals divided into a plurality of frames and time slots for uplink and downlink communications, the uplink and downlink time slots having a time offset therebetween during a non-test mode, the base station including at least one transmitter and receiver, comprising: means for directionally coupling an-output signal of the transmitter during a predetermined downlink time slot, the output signal of the transmitter being a test stimuli; a test loop circuit, coupled to the directional coupling means, for transposing the frequency of the output signal from the transmitter to a frequency capable of being received by the receiver of the base station during a predetermined uplink time slot; and means for coupling the output of the test loop circuit to the receiver, such that the predetermined downlink time slot and the predetermined uplink time slot are looped; wherein the predetermined downlink time slot and the predetermined uplink time slot are simultaneous in time only during a test mode, and a test is performed using the signal having the transposed frequency.
Claim 24
Dependent Claim
72 words
An apparatus according to claim 21 wherein the test loop circuit includes first means for mixing the signal from the transmitter with a signal having a predetermined frequency in order to generate a signal having an intermediate frequency, and second means for mixing the signal having the intermediate frequency with a signal having a second predetermined frequency in order to generate the signal having a frequency that is receivable by the receiver.
Claim 25
Dependent Claim
24 words
An apparatus according to claim 22 wherein the test loop circuit further includes means for variably attenuating the signal from the first mixing means.
Claim 26
Independent Claim
21 words
An apparatus according to 21 which further includes means for measuring the power of a signal from the test loop circuit.
Claim 27
Independent Claim
21 words
An apparatus according to 21 which further includes means for measuring the power of a signal from the test loop circuit.
Claim 28
Dependent Claim
26 words
An apparatus according to claim 23 wherein the test loop circuit further includes signal generating means for providing signals to the first and second mixing means.
Claim 29
Dependent Claim
34 words
An apparatus according to claim 21 which further includes a time switch that causes the predetermined downlink time slot to be looped with the predetermined uplink time slot, leaving the other time slots unaffected.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-28 | 1999-11-27 | 2000-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-28 | 2003-11-27 | 2004-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-28 | 2007-11-27 | 2008-05-28 | $7700.00 | Window Closed / Lapsed |