Constructions of Low/Zero Correlation Zone Sequence Sets and Their Application in Grant-Free Non-Orthogonal Multiple Access System

摘要

In the massive machine-type communication scenario,aiming at the problems of active user detection and channel estimationin the grant-free non-orthogonal multiple access (NOMA) system, new setsof non-orthogonal spreading sequences are proposed by using the zero/lowcorrelation zone sequence set with low correlation among multiple sets.The simulation results show that the resulting sequence set has low coherence,which presents reliable performance for channel estimation and activeuser detection based on compressed sensing. Compared with the traditionalZadoff-Chu (ZC) sequences, the new non-orthogonal spreading sequenceshave more flexible lengths, and lower peak-to-average power ratio (PAPR)and smaller alphabet size. Consequently, these sequences will effectivelysolve the problem of high PAPR of time domain signals and are moresuitable for low-cost devices in massive machine-type communication.