The Research And Implementation Of The TD-LTE Inter-frequency Networking System Based On The Total Amount Of Interference Assessment

TD-LTE(Time-division Long-Term Evolution), the leading 4G broadband mobile telecommunication technology led by China, is the seamless evolution of the 3G TD-SCDMA(Time Division-Synchronous Code Division Multiple Access) telecommunication technology innovated by China independently, now it is one of the international 4G standards adopted by the International Telecommunication Union. Due to the superb characteristics it inhabits, e.g., the high efficiency of frequency usage, the operational flexibility of throughput adjustment, the grand data transmission volume and the high speed of data transfer rate, under the current difficulties the international telecommunication industry is facing, such as the shortage of frequency resources, the steadily huge increase of mobile internet traffic, TD-LTE has been granted a glowing future by the international industrial organizations and companies. The current development of TD-LTE proves this future, now it has formed a broad international telecommunication industrial chain, led by China, participated with all key communication companies worldwide. Nearly all the telecommunication equipment and chip manufacturers are now supporting this technology and it’s been commercialized in most cities of China.With the breakthrough of the mobile telecommunication technology, smart phone is now playing an indispensable role in people’s daily lives, it can bring us so much convenience and the mobile internet is much more demanded by young generation, but all of this depends on a well-functioned mobile telecommunication network, which is directly reflected in the download rate people is satisfied with. Download rate directly reflects the user’s perception of the data traffic business quality, with the rapid growth in the data traffic business, the number of users and the volume of data are increased dramatically, the download rate sensed by mobile phone users is now a key factor in China Mobile Communication network quality evaluation.This paper, based on the large-scale deployed 4G base stations network infrastructure, analyzes the alternative networking solutions for TD-LTE as well as the discrepancy between the intra-frequency and inter-frequency networking. To fulfill the customer demands and a high KPI performance, this paper studies the implementation methods for TD-LTE inter-frequency networking and analyzes the networking-optimized and projected approaches.In the construction of TD-LTE network, in accordance with the relevant requirements, Qingdao urban TD-LTE network utilizes a 20MHz single carrier D band (2575-2635MHz) on forming the intra-frequency network for construction and optimization. Consider the terrible inter-cell co-channel interference caused by the intra-frequency TD-LTE networking and the sufficient frequency resources on the 50M bandwidth on TD-LTE D-band under the low network payload, in a wireless network, an inter-frequency networking on a single carrier-frequency and optimized frequency allocation method can significantly drop the internal networking noise and efficiently improve the networking communication quality by raising the downlink data transfer speed.By gathering and analyzing the large amount of tests data currently on-going under an intra-frequency networking, such as the cell electrical level and the coverage rate of the network, the formation of interference matrix under the same frequency is produced. The output of frequency demultiplication calculation on the interference matrix is then manually checked so as to realize the inter-frequency allocation scheme and apply the scheme in the current TD-LTE network system.According to the optimization test result, it’s found that the single carrier-band inter-frequency networking approach applied in some urban Qingdao areas, along with the frequency allocation method based on the amount of interference assessment described in this paper, can significantly drop the network interference and improve the downlink rate by 20-30%. In some critical regions, through the reduction of manual control on frequency reuse among different spots for the inter-frequency networking, a higher downlink rate can be achieved. This would provide strong technical support for CMCC to take advantage in the competitive TD-LTE market and bring significant social and economy benefits.