The filter and antenna are two key components of the radio frequency (RF) front-end. When the antenna is directly connected with the filter, additional mismatch losses will be caused. Therefore, the antenna and filter are integrated into a single device to provide both filtering and radiating functions. In this way, many advantages, like low cost, light weight, small size and lower insertion loss can be obtained. In this paper, the co-design approaches of RF filter-antenna are reviewed. Based on the open literatures, the integrated approaches of filtering antenna can be classified into five main categories:1) Co-design by optimizing the interfacing impedance, 2) co-design according to the synthesis approach of filter, 3) co-design by embedding novel resonators within the feeding structures, 4) co-design by employing auxiliary physical structures, and 5) other methods. The RF filter-antenna system can improve the integration degree of RF front-end, reduce its size and cost, and optimize its performance.

Coordinated Multi-Point (CoMP ) transmission/ reception technology has been the focus of much attention recently and has becom a key research interest in 3GPP LTE-Advanced due to its ability to improve both cell-edge and average system performance. However, CoMP technology requires brand-new handover mechanism, or else its real performance will be limited. This paper proposes a novel handover mechanism supporting CoMP based on the handover scenario in CoMP communication system architecture, including information sharing and signaling transmission procedure of CoMP cooperating sets handover and CoMP transmission points selection/update. The proposed scheme could not only support CoMP well, but also reduce the overhead of information exchange and signaling transmission.

Based on spectrum sensing, dynamic spectrum allocation and reconfiguration technologies in Cognitive Radio (CR ), this paper fully considers the matching issues between short-term spectrum characteristic and service characteristic. In the communication process, the network-side selects switch terminals to initiate handover command to solve problems due to limited capacity of the system, such as overload and new session decline, improving the success rate of switching on the premise of ensuring user’s QoS, reducing blocking probability with more session admission, eliminating overload, increasing system throughput, and improving the whole system performance.

This paper analyzes current spectrum utilization from all aspects based on related methods of spectrum measurement. The measurement results show that some spectrum resources are not used effectively due to current fixed spectrum allocation policy, and the spectrum occupancy varies dramatically in terms of time and space. These results provide basis for the development of next generation wireless communication technologies such as Cognitive Radio (CR ).