OFDM system with reverse link interference estimation
AssigneeApple Inc.
InventorsJianming Wu, Wen Tong, Peiying Zhu
Life of this patent
Estimating the term…
Abstract
A new method of performing interference estimation to allow the data packets to be efficiently delivered in an OFDM system. The interference estimation is performed on average over each frame for each mobile station individually in both frequency and time domains. Based on the estimated interference, the CIR can be determined by the BTS based on channel response estimates made by the BTS, or by the MS based on channel response estimates made for the uplink assuming a symmetrical channel. Numerical results show that the CIR estimation error could be very small if a sub-channel is considered as the minimum transmission unit. In terms of the aggregate throughput, the interference estimation method can provide a significant gain.
Claims21
A method for estimating a carrier-to-interference ratio (CIR) in an OFDM system, the method comprising:
- estimating an average interference level for at least one mobile station based on signals received during an OFDMA frame on sub-channels associated with the mobile station;
- performing channel estimation for each sub-carrier and each mobile station to estimate a channel response for each mobile station;
- and
- estimating a CIR for each mobile station based on the estimated channel response and the estimated average interference level for each mobile station.
Apparatus for estimating a carrier-to-interference ratio (CIR) in an OFDM system, the apparatus comprising:
- an interference estimator operable to estimate an average interference level for at least one mobile station based on signals received during an OFDMA frame on sub-channels associated with the mobile station;
- a channel estimator operable to perform channel estimation for each sub-carrier and each mobile station to estimate a channel response for each mobile station;
- and
- a CIR estimator operable to estimate a CIR for each mobile station based on the estimated channel response and the estimated average interference level for each mobile station.
Dependencies are inferred from the claim text.