| 摘要 |
In a method of a heterodyne FDD receiver for enabling reception of a multi-band RXRF signal spectrum, an RXRF signal spectrum is received 700, which comprises a lower frequency band and a higher frequency band. A Local Oscillator, LO, output frequency, fLO, is selected 702 based on a frequency fA of the lower frequency band, and a frequency fB of the higher frequency band. Moreover, the RXRF signal spectrum is frequency shifted into an RXIF signal spectrum, by mixing 704 the RXRF signal spectrum with the LO output frequency fLO. The LO frequency fLO is selected 702 to satisfy: fA < fLO < fB, where fA and fB are any frequency of the lower or higher frequency band, respectively, such that when mixing the RXRF signal spectrum, one of the lower frequency band and the higher frequency band is frequency shifted into a first frequency band of the RXIF signal spectrum, and one another of the lower frequency band and the higher frequency band is frequency shifted folded into a second frequency band of the RXIF signal spectrum. Thereby the heterodyne FDD receiver is enabled to process the first frequency band of the RXIF signal spectrum and the second frequency band of the RXIF signal spectrum into two separate frequency bands of a baseband. The multi-band receiver will be capable of handling widely separated frequency bands, e.g. separated about 1GHz, without implementing multiple branches in the multi-band receiver. |
