Realization of O-QPSK IF receiver for small and medium capacity digital radio relay systems

We describe the receiver for O-QPSK modulation with coherent detection for small and medium capacity digital radio relay systems (DRRS). Its characteristics are: large dynamic range (from -70 dBm to 0 dBm), large carrier recovery pull in range (at least /spl plusmn/700 kHz) and resistance to cochannel, adjacent channel and continuous wave interference according to ETSI standards. Very important is that the receiver is designed for an extended temperature range from -30/spl deg/C to +55/spl deg/C. This receiver is used in Institute IMTELs DRRS RRU13A and RRU23A.