Before revision: To meet the increasing requirements for wireless communications, unlicensed access is being accepted as one of the most significant solutions to improve resource availability and system scalability in 5G NR, which is called NR-based Access to Unlicensed Spectrum (NR-U) . As an OFDM system, 5G will face the problem of high Cubic Metric (CM). To satisfy the usage rules of Occupied Channel Bandwidth (OCB) of unlicensed spectrum, NR-U's PRACH and PUCCH , which are composed of CAZAC sequences, have to use some sequence repetition mechanisms in frequency domain , which brings more serious CM problems.
After revision: To meet the increasing requirements for wireless communications, unlicensed access is being accepted as one of the most significant solutions to improve resource availability and system scalability in 5G NR, which is called NR-based Access to Unlicensed Spectrum (NR-U) of 5G system, to satisfy the rules of Occupied Channel Bandwidth (OCB) of unlicensed spectrum, NR-U's PRACH and PUCCH , which are composed of CAZAC sequences, have to use some sequence repetition mechanisms in frequency domain , which brings more serious CM problems.