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. Based on the characteristics of Constant Amplitude Zero Auto-correlation(CAZAC) sequences  , which are used for PRACH and PUCCH (refer to PUCCH format 1 and format ) in 5G , this paper proposes new mechanisms of CM reduction for PRACH and PUCCH with the repeated sequence in frequency domain considering the design principles to ensure the sequence performance of the auto-correlation and cross-correlation for CAZAC sequence-based PRACH and PUCCH . Then the proposed CM schemes are evaluated and the optimized parameters for the proposed CM schemes are further provided considering CM performance and the complexity.
In NR-based Access to Unlicensed Spectrum (NR-U) of 5G system, to satisfy the rules of Occupied Channel Bandwidth (OCB) of unlicensed spectrum, the channels of PRACH and PUCCH have to use some sequence repetition mechanisms in frequency domain . These repetition mechanisms will cause serious cubic metric(CM) problems for these channels, although these two types of channels are composed of Constant Amplitude Zero Auto-correlation(CAZAC) sequences .. Based on the characteristics of CAZAC sequences , which are used for PRACH and PUCCH (refer to PUCCH format 0 and format 1 ) in 5G NR, in this paper, we propose some new mechanisms of CM reduction for these two types of channels considering the design principles to ensure the sequence performance of the auto-correlation and cross-correlation . Then the proposed CM schemes are evaluated and the optimized parameters are further provided considering CM performance and the complexity.
R
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
In
R
. As an OFDM system, 5G will face the problem of high Cubic Metric (CM). To satisfy the usage
of 5G system, to satisfy the
R
NR-U's
the channels of
D
, which are composed of CAZAC sequences,
R
, which brings more serious CM problems. Based on the characteristics of
. These repetition mechanisms will cause serious cubic metric(CM) problems for these channels, although these two types of channels are composed of
A
.. Based on the characteristics of CAZAC sequences
R
1 and format
0 and format 1
R
, this paper proposes
NR, in this paper, we propose some
R
PRACH and PUCCH with the repeated sequence in frequency domain
these two types of channels
D
for CAZAC sequence-based PRACH and PUCCH
D
for the proposed CM schemes