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US 6,650,872 B1Granted
Method and device for estimating a carrier-to-interference ratio in a radio communication system
AssigneeTelefonaktiebolaget LM Ericsson
InventorAnders Karlsson
Life of this patent
Estimating the term…
Abstract
The carrier-to-interference ratio in a radio communication system is estimated by using measurements of the received signal strength in a communication channel within periods of time when transmission is discontinued and measurements of the received signal strength in the communication channel within periods of time with transmission.
Claims42
A method of estimating a carrier-to-interference ratio in a radio communication system, comprising the steps of:
- selecting a radio communication channel capable of discontinuous transmission;
- establishing from signals received via the communication channel whether discontinued transmission is activated on the communication channel;
- measuring a first received signal strength in the communication channel within periods of time when transmission is discontinued;
- measuring a second received signal strength in the communication channel within periods of time during transmission;
- and
- estimating the carrier-to-interference ratio of the channel by using an estimate of a ratio of the measured second received signal strength to the measured first received signal strength.
3 more elements
A method of controlling channel selection within a radio communication system having at least two communication devices, comprising the steps of:
- a.) establishing a communication channel between a first and a second communication device;
- b.) providing a list of frequencies that can be used for the communication channel;
- c.) for each frequency in the list carrying out the steps of:
- 1.) establishing whether discontinuous transmission is activated and if so:
- i.) measuring a first received signal strength at the frequency within periods of time when transmission is discontinued;
- ii.) measuring a second received signal strength at the frequency within periods of time during transmission;
- and
- iii.) calculating an estimate of a carrier-to interference ratio at the frequency using the measured first and second signal strengths;
- d.) ranking the frequencies of the list according to the corresponding estimated levels of the carrier-to-interference ratio;
- e.) communicating information representing at least one frequency having a greatest estimated carrier-to-interference ratio to at least the first and the second communication devices;
- and
- f.) setting up a subsequent communication channel between the first and the second communication devices using at least the at least one frequency.
9 more elements
A method of operating a communication device having a radio receiver and a radio transmitter, the method comprising the steps of:
- selecting a radio communication channel capable of discontinuous transmission;
- measuring a first received signal strength in the communication channel within periods of time when transmission is discontinued;
- measuring a second received signal strength in the communication channel within periods of time during transmission;
- and
- transmitting information representing the measured first received signal strength and the measured second received signal strength to an external device by means of the transmitter to enable said external device to use the transmitted information to provide an estimate of a carrier-to-interference ratio of said communication channel.
2 more elements
A radio communication device, comprising:
- an antenna;
- a radio receiver connected to the antenna and configured to receive at least one signal picked up by the antenna over a selected channel;
- a measuring device connected to the radio receiver and configured to measure a received signal strength for the received signal;
- a controller connected to the radio receiver and configured to determine periods of time corresponding to transmission and periods of time corresponding to discontinued transmission within the selected channel;
- and
- a calculation unit connected to the radio receiver, the measuring device and the controller, the calculation unit being configured to estimate a carrier-to-interference ratio, C/I, using at least one measured signal strength value from at least one of the periods of discontinued transmission and at least one measured signal strength value from at least one of the periods of transmission.
3 more elements
A radio communication device, comprising:
- an antenna;
- a radio receiver connected to the antenna and configured to receive a signal picked up by the antenna over a selected channel;
- a measurement unit connected to the radio receiver and configured to measure a received signal strength associated with the signal;
- a controller unit connected to the radio receiver and configured to determine periods of time corresponding to transmission and periods of time corresponding to discontinued transmission within the selected channel;
- a detector connected to the radio receiver and the controller unit and configured to determine if discontinued transmission is activated on the selected channel;
- and
- a transmitter connected to the antenna, the measurement unit and the controller unit, the transmitter being configured to transmit information representing the measured signal strength for the signal received during at least one period of discontinued transmission, and information representing the measured signal strength for the signal received during at least one period of transmission.
4 more elements
A method of estimating a carrier-to-interference ratio in a radio communication system, comprising the steps of:
- selecting a radio communication channel capable of discontinuous transmission;
- measuring a first received signal strength in the communication channel within periods of time when transmission is discontinued;
- measuring a second received signal strength in the communication channel within periods of time during transmission;
- and
- calculating an estimate of the carrier-to-interference ratio of the channel by using the measured first and second signal strengths, wherein the first measured signal strength corresponding to periods of discontinued transmission, I*, and the second measured signal strength corresponding to periods of transmission, C+I*, are determined in dBm and a carrier-to-interference ratio, C/I, is estimated in dB according to the formula:
- (C/I)dB≈((C+I)/I)dB=(C+I*)−(I*).
3 more elements
A method of estimating a carrier-to-interference ratio in a radio communication system, comprising the steps of:
- selecting a radio communication channel capable of discontinuous transmission;
- measuring a first received signal strength in the communication channel within periods of time when transmission is discontinued;
- measuring a second received signal strength in the communication channel within periods of time during transmission;
- and
- calculating an estimate of the carrier-to-interference ratio of the channel by using the measured first and second signal strengths, wherein the step of calculating an estimate of the carrier-to-interference ratio further includes:
- providing a predetermined correction value which corresponds to the estimated C/I value;
- and
- correcting the estimated C/I value by using the predetermined correction value according to a correction function.
5 more elements
A method of estimating a carrier-to-interference ratio in a radio communication system, comprising the steps of:
- selecting a radio communication channel capable of discontinuous transmission;
- measuring a first received signal strength in the communication channel within periods of time when transmission is discontinued;
- measuring a second received signal strength in the communication channel within periods of time during transmission;
- and
- calculating an estimate of the carrier-to-interference ratio of the channel by using the measured first and second signal strengths, wherein the first measured signal strength corresponding to periods of discontinued transmission, I*, and the second measured signal strength corresponding to periods of transmission, C+I*, are determined in dBm and the carrier-to-interference ratio, C/I, is estimated in dB by calculating according to the formula:
- ( C / I ) dB = 10 log [ 10 [ ( C + I * ) - ( I * ) ] / 10 - 1 ] .
3 more elements
Dependencies are inferred from the claim text.