Method and apparatus for testing a base station in a time division multiple access radio communications system
First Claim
1. 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.
1 Assignment
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Accused Products
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.
81 Citations
26 Claims
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1. 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:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. 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:
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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. - View Dependent Claims (22, 23, 25, 26)
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24. An apparatus according to 21 which further includes means for measuring the power of a signal from the test loop circuit.
Specification