| 摘要 |
The invention relates to a digital radio link and radio link system comprising two radio link terminals (A, B) establishing a fixed radio connection between them. In the system, the radio link terminals transmit alternately at the same radio frequency, each one of the radio link terminals (A, B) comprising (a) baseband modulator means (12a; 12b) in the transmitting branch for generating baseband modulation signals from a digital data stream (TXD); (b) demodulator means in the receiving branch for generating a base-band data stream (RXD) by demodulating baseband signals to be received; (c) means (22, 24) for forming an RF transmitting signal directly from said baseband modulation signals and for forming said baseband signals to be received directly from the RF signal to be received; and (d) timing means (16a; 16b) for connecting the radio link terminal alternately to a transmitting and receiving mode. To achieve a link and a link system that are economically advantageous and as simple as possible, the means comprise a single common quadrature mixer (22) and a local oscillator (24) controlling it, the transmitting and receiving branch being separated at the baseband.
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