Non-Blind DOA Estimation Method for 5G Mobile Terminal
Yijie Ren, Wang Xiaojun · 2021
With the development of smart antenna theory, positioning technology based on adaptive antenna array has been widely used. This paper mainly studies the algorithm of fast and accurate positioning of mobile terminals based on the DMRS sequence of 5G uplink channel by utilizing adaptive antenna array. Firstly, this paper introduces the adaptive antenna arrays ULA. After that, three kinds of interference were proposed which may exist when doing DOA estimation. Subsequently, the system's transceiver model is established. The process can be summarized as follows: The transmitter generates the DMRS sequence and then adds it to the sub carrier for transmission. The receiver processes the received signal and DMRS sequence. According to the position of the peak of the energy spectrum, the sequence segment where the target source DMRS is located is extracted, and then LMS algorithms are used for DOA estimation. In addition, combined with the characteristics of Sigmoid function and logarithmic function, an improved LG-SVSLMS algorithm is proposed. Finally, each LMS algorithm is applied to the positioning of mobile terminals under the 5G system, and simulation analysis is performed in three different environments. It is concluded that the LG-SVSLMS algorithm has strong anti-interference ability when dealing with multi-source signal interference, cochannel interference and non-synchronous interference, and can make the curve converge faster, which verifies the optimal performance of the LG-SVSLMS algorithm. Also, under the condition of ensuring the effective positioning, the range of the incident Angle of the target source is obtained.11Foundation items: Social Development Projects of Jiangsu Science and Technology Department(No.BE2018704)