LDPC 5g

[MarHajj]

Hi,
I am working on a goal to simulate BER function of Eb/N0 using external data channel (measured and/or simulated).
I am using 1 transmitter and 1 receiver with one antenna for transmitting and receiving (SISO).

My OFDM ressource grid is :

ressourceGrid(num_ofdm_symbols=14,
fft_size=1024,
subcarrier_spacing=120e3,
num_tx=1,
num_streams_per_tx=1,
cyclic_prefix_length=72,
num_guard_carriers=[115,116],
dc_null=True,
pilot_pattern="kronecker",
pilot_ofdm_symbol_indices=[2,11])
with a code rate R = 0.36 (3GPP table 5.1.3.1-2 of the norme 38.214 (section 5.1.3)) and a 16 QAM (4 bits).

The code provide an error due to the number of information bits k is too large (attached screenshot)
Note that :
n = nbre of data symboles x nbre of qam bits
k = n x code rate

In this case can i segment my data into a packet of length less than 8448 or i have just to reduce my fft size ?

Thank you

Marwan EL HAJJ

[jhoydis]

Hi Marwan,

Indeed, the code length in 5G is limited to 8448. Since Sionna does not provide transport block segmentation, you can do one of the following:

• Reduce the FFT size
• Reduce the number of OFDM symbols
• Concatenate multiple codewords