| 摘要 |
There is provided mitigating of interference from a narrowband signal during transmission of a multicarrier modulated signal. Coexistence of narrowband radio access technology, RAT, like GSM or EDGE, with wideband RAT like LTE based on OFDM is improved. The application proposes to use predistortion such that it removes most of the narrowband signal interference that has leaked outside said narrowband bandwidth by application of the FFT. Indeed due to the lack of orthogonality, the OFDM fast Fourier transform (FFT) unit at the UE receiver will spread some GSM interference over the whole LTE frequency band, with significant amounts of GSM interference being leaked to many sub-carriers of the LTE signal. The multi-RAT transmitter precomputes said out-of-band leakage of the narrowband signal and subtracts it from the transmitted signal. Legacy receivers (ie without any particular inter-RAT interference cancellation ability) will have improved SINR thanks to the precompensation at the transmitter. |
