| With the wireless communication developing, new technologies are invented and put into practice, and make our life more convenient than the past. Meanwhile, it also brings new challenges to the research of wireless communication system.With commercial spread of new wireless standards, it may bring interference to the current system. For example, in order to meet the rapid growing requirements of high-speed data transmission and multimedia service, it becomes inevitable to deploy LTE and LTE-Advanced system. There are many issues that have to be taken into consideration when deploying these two kinds of newly high-speed system, such as the network transition, shortage of frequency spectrum, benefit of telecom operators and so on. Given those problem mentioned above, it seems to be a better choice to take smooth transition from current system to LTE or LTE-Advanced system. Consequently, the smooth transition will cause co-channel and adjacent-channel interference inevitably. And it will affect the performance of receiver badly, drop the quality of communication and limit the capacity and coverage of the system. So it’ll be very valuable to research interference coexistence between newly system and the existing ones deeply.The architecture of the network may be changed due to the introduction of new network node. So we need to modify the way of researching radio-frequency performance of the wireless communication system when adding new node into the current system. Relay is introduced to the LTE since Release9and adds new network nodes into the system which is called Relay Node(RN). With the existence of RN, there is new interference introduced to the macro LTE network, and it results in a more complex structure of interference. RN and macro LTE network will cause interference to each other. So we must consider both sides when analyzing the performance of radio-frequency of RN.With the development of new application field, some new skills should be introduced into the system such as network topology, propagation model, simulation process and evaluation methods, the old ways need to modified to become inappropriate to the new fields. So we need to develop new methods aiming at new scenarios. Internet of things has attracted wide attention due to its utility and feasibility under the Smart Home situation. However, restricted by the non-uniform standard and variety of application scenarios, the research of interference coexistence under Smart Home scenario hasn’t been touched. And this research will provide valuable experience which can be applied to other Internet of Things-involved interference coexistence scenario research.According to new technologies, new network node, and new application field of wireless communication system, this paper selects three relevant topics to research. Firstly, this paper researches the interference type and strength of LTE-Advanced and TD-SCDMA system when they coexist in the same area via the deterministric analysis and Monte Carlo simulation. Secondly, this paper does research on the performance of Relay access link receiver, and simulates and obtains the key performance indicator of the receiver such as reference sensitivity and dynamic range. Thirdly, this paper introduces the basic information of WiFi and ZigBee under the internet of things of Smart Home scenario such as network topology, propagation model, system parameters, key algorithm model, system process and evaluation criteria. Besides, this paper also simulates the fixed-deployment and random-deployment scenarios, analyzes the simulation results and gives recommendations to these scenarios in terms of interference coexistence. |
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