NR-Secondary Synchronization Signal

NR-SSS(Secondary Synchronization Signal)

• SSS sequences are based on maximum length sequences, known as M-sequences made up of 127 values
• SSS determines Physical Layer Cell ID

NR-SSS Sequence Generation Algorithm

NR-SSS Python Code

def nr_sss_gen(N_id1, N_id2):

LEN = 127
x0 = np.zeros(LEN)
x0[0:7] = [1, 0, 0, 0, 0, 0, 0]
for i in range(0, LEN - 7):

x0[i + 7] = (x0[i + 4] + x0[i]) % 2 x1 = np.zeros(LEN)

x1[0:7] = [1, 0, 0, 0, 0, 0, 0]
for i in range(0, LEN - 7):

x1[i + 7] = (x1[i + 1] + x1[i]) % 2 d_sss = np.zeros(LEN)

m0 = int(15 * math.floor(N_id1/ 112) + 5 * N_id2)
m1 = N_id1 % 112
for n in range(0, LEN):

d_sss[n] = (1 - 2 * x0[((n + m0) % LEN)]) * (1 - 2 * x1[(n + m1) % LEN]) 

return d_sss

[Reference]

• 3GPP TS 38.211 V15.8.0 (2019-12), "NR; Physical channels and modulation"