Uplink LBT Design and Performance Evaluation in Licensed-Assisted Access to Unlicensed Spectrum

• Main Authors: LIN, CHIA-FENG, 林家豐
• Other Authors: PAN, JEN-YI
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/02382602343743503968

碩士 === 國立中正大學 === 通訊工程研究所 === 105 === The number of smart mobile devices (SMDs) is growing and sundry applications appeared for SMDs, which has resulted in the high volume of the data traffic in mobile communication networks (MCNs) year after year. In order to meet its ever-growing demand, it is necessary that bandwidth should be augmented in MCNs. MCNs work based on licensed band which is usually allocated and governed by the government. The license is obtained by means of bidding, which increases the cost but offers limited resources. Thus, operators must pay a great deal to provide this demand. To deal with the limited resources, the 3rd Generation Partnership Project (3GPP) proposed a concept of Licensed-Assisted Access (LAA) in September 2014. LAA uses the carrier aggregation (CA) technique realized in Long-Term Evolution (LTE) within a small cell, which enables transmission in both license bands and unlicensed bands. In addition, the license band may carry control information to assist access to the unlicensed band on this extended feature of LTE, increasing the bandwidth of the networks, just as the name “LAA” applies. However, the unlicensed band that LAA is planning to work on is presently occupied by IEEE 802.11 (Wifi) wireless communication technology. LAA’s use will inevitably affect the IEEE 802.11 working, so how LAA coexists with IEEE 802.11 is an important issue. This technology is still at the stage of being discussed and designed. This study proposes a feasible LAA uplink listen before talk (LBT) mechanism for the uplink transmission, which is not well addressed yet in 3GPP, and evaluates the performance with analyzing the impact on IEEE 802.11.