Avoidance of adjacent channel crossed-slot interference in TD-CDMA

Abstract

In the case of serving different types of services like mobile communication and mobile broadcast on the adjacent frequency bands in TD-CDMA, adjacent channel crossed-slot interference, caused by different ratios of uplink (UL) and downlink (DL) slots in these services, occurs. Usually, the number of time slots of broadcast DL is more than that of communication DL. In other words, these services have different switching points between DL and UL. Therefore, time slots of communication UL could exit at the same time as those of broadcast DL. These slots are called crossed-slots. Practically, antennas for communication and broadcast are close to each other such as on the same building. That is why communication UL signals with weak power are interfered by broadcast DL signals with strong power in the crossed-slots. We have proposed a scheme which can avoid adjacent channel crossed-slot interference and can realize smooth integration of mobile communication and mobile broadcast in TD-CDMA.