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"
NR-PSS(Primary Synchronization Signal)
- PSS sequences are based on maximum length sequences, known as M-sequences made up of 127 values
- PSS sequence uses NR Downlink Frame Synchronization
- PSS determines Physical Layer Cell ID and provides Group ID value
NR-PSS Sequence Generation Algorithm
- It is generated by d(n) and it is determined by N(2)ID
NR-PSS Python Code
- It is based on python 2.7 and numpy Package
- nr_pss_gen python function
def nr_pss_gen(N_id2):
len = 127
len_intial = 7
d = np.empty(len)
x = np.zeros(len)
x[0:7] = np.array([0,1,1,0,1,1,1])
for i in range(len_intial,len):
x[i] = (x[i+4-len_intial] + x[i-len_intial]) % 2
for n in range(len):
m = (n + 43*N_id2) % len
d[n] = 1 -2*x[m]
return d
[Reference]
- 3GPP TS 38.211 V15.8.0 (2019-12), "NR; Physical channels and modulation"
