frequency hopping). 4.6. Transmission in uplink The communication on the uplink channel is based on either the OFDM signal or on the DFT-S-OFDM signal (see section 4.1.1). The DFT-S-OFDM signal reduces energy consumption and is obtained by applying an additional Fourier transform in the transmission chain, compared to the OFDM transmission chain. The reference signals associated with this signal will be CAZAC sequences (Constant Amplitude Zero AutoCorrelation). CAZAC sequences allow energy consumption to be reduced (constant amplitude). Zadoff-Chu sequences are CAZAC sequences, complex sequences whose versions obtained by cyclic shifts are orthogonal. The Zadoff-Chu sequences of length M are defined by a root u forming a base sequence, from which orthogonal sequences are derived by cyclic shifting. NG-RAN and 5G-NR The formulation of a Zadoff-Chu sequence is as follows: In the specifications of 3GPP Release R.16, CAZAC sequences are named ru,v: - 30 groups of CAZAC sequences (u = {0,... 29}) of length M are defined; - in each group, the basic sequence corresponds to V = 0. If the length of the sequence is greater than or equal to 36 (equivalent to 3 RB), then ru,o(n)=z" = If the length of the sequence is equal to {6,12,18,24}, then with E {-3,-1,1,3} . The value of Q(n) is defined by Tables 5.2.2.2-1/4 in specification TS 38.211. the length of the sequence is equal to 30, then =e 5G-NR supports DFT-S-OFDM and OFDM in the uplink direction. When the OFDM signal is used, the reference signal is a Gold sequence. The Gold sequence r(n) is generated from two M-sequences (pseudo-random sequences) with c(n) extracted from 2 M-sequences: c(n) = =(x,(n+N)+x2(n+N))1 mod2 x,(n+31)=(x(n+3)+x,(n))mod2 x2(n+31)=(x2(n+3)+x2(n+2)+x2(n+1)+x2(n))mod2 = 2 4.6.1. Physical reference signals 4.6.1.1. Physical SRS signal The physical SRS (Sounding RS) signal is a reference signal transmitted by the UE. The gNB performs a coherent demodulation of the received signal and assesses 5G-NR Radio Interface - The Physical Layer the transfer fun