NB-IoT physical random access analysis and receiver detection algorithm

Abstract

NB-IoT is an emerging cellular technology that provides better coverage for applications with large connectivity,low power,low throughput,low device cost and high latency tolerance.Compared with Long Term Evolution(LTE)system,the Narrow-band Physical Random Access Channel(NPRACH)of NB-IoT system has been modified a lot.Therefore,the structure design of NPRACH in NB-IoT system is analyzed in detail by comparison with LTE system.And a 2-D FFT-based NPRACH receiver detection algorithm is proposed. Through MATLAB simulation analysis,the results show that under different coverage levels,the algorithm detects NPRACH Preamble missed detection probability of less than 0.05% Misdetection Probability(MDP),Alarm Probability(FAP)less than 0.1%, which meets the standard requirements of 1% MDP and 0.1% FAP indicator,and the probability of Time-of-arrival(ToA) Error in the range of -2.5～2.5 μs is higher than 95%.

Keywords

• NB-IoT
• random access
• Preamble
• 2-D FFT