Load-Aware Adaptive Threshold Adjustment for Licensed Assisted Access of LTE

In long term evolution (LTE), the component carriers in 5GHz are planned to be utilized without licenses, which obtains a new name for this feature of the LTE, i.e., licensed assisted access (LAA). The listen before talk (LBT) is required when these unlicensed carriers are utilized. The threshold of listen (channel sensing) is very critical, which decides whether the afterwards burst transmission are in time. Beside, it may cause buffer overflow without a proper threshold value for channel sensing, since the traffic arrival rate is a random variable following poisson distribution which could produce heavy load for some nodes. Thus, to solve the above problems, we propose a load-aware adaptive threshold adjustment method for the down link of Licensed Assisted Access of LTE. Both the load and transmission opportunities are concerned. The results from system level simulation confirm the effectiveness of our design, especially in heavy traffic cases.