| 摘要 |
<p>A system and method for simultaneous transmission and receival where the received signal (24) is downconverted in a downconverting unit (25) by using a portion (35) of the transmitted modulated signal (31) as LO for the downconversion. The downconversion is performed to an intermediate frequency signal (26) having a frequency (f2)-(f1) equal to the difference between the frequency (f2) of the transmitted signal and the frequency (f1) of the received signal. There is provided a common antenna (20) for transmitting and receiving, and a duplex filter (21) in front of the antenna (20) to separate the transmitted signal (29) and the received signal (22), with the transmitter data (34) on the transmitter side having been applied to a modulator (33). In front of the duplex filter on the transmitter side is provided a power amplifier (30). On the receiver side there is, in addition, provided a demodulator (27) to permit withdrawal of user data (28) for the user on the receiver side. Compensation for the modulation introduced by the signal (35) in the downconversion unit (25) is provided in the receiver by a device where the transmitted phase (46a) is used as a reference, delayed in a time delay unit (53) by an appropriate delay, and where this delay unit may be estimated and updated in order to compensate for variable delay in the outer signal path.</p> |
