Noise immunity of a coherent reception of signals with multiple phase shift keying in the presence of retranslated interference
Signals with multiple phase shift keying have a number of properties that determine the promise of their use in multi-purpose digital communication systems. The signals considered are basic for a number of adopted wireless network protocols: IEEE 802.11, cellular CDMA networks, digital satellite television DVB-S and DVB-S2 / S2X.In such radio systems, at the receiver input, along with noise interference, there may be other types of interference, both unintentional and intentional. One of the most common is a retranslated interference, for example, such interference occurs during radio transmission in an urban environment with a high density of building. The dangerous effect of the retranslated interference on the quality of information reception is confirmed by a number of studies. The results show that the reception of signals with multiple phase shift keying is very strongly influenced by the retranslated interference and with the increase in the position of the MPSK signals, this influence is enhanced. It has been established that if the noise immunity of the bit reception of BPSK and QPSK is the same for noise interference, then in the presence of a relayed interference, the QPSK receiver starts to lose significantly.