How do I run the SIONNA 5G-LDPC codes for BPSK modulation?

[yossefyossef]

Hi all,

Can someone please help me, how to run the SIONNA for BPSK modulation, for the long codes of LDPC?

That means, I write the following value:
num_bits_per_symbol = 1 # BPSK

I got the following error message:
“num_bits_per_symbol must be multiple of 2”.

Can someone please help me?

Thanking in advance, and best regards,
Yossef Yossef
Email: [email protected]

[yossefyossef]

Note:
I use the code from the following link:
https://nvlabs.github.io/sionna/examples/5G_Channel_Coding_Polar_vs_LDPC_Codes.html

[jhoydis]

Hi Yossef,

For BPSK, you need to use PAM modulation. See https://nvlabs.github.io/sionna/api/mapping.html#sionna.mapping.Mapper
This code would give you a BPSK modulation:

mapper = Mapper("pam", 1)

Hope this helps.

[yossefyossef]

So, instead to write:
num_bits_per_symbol = 1 # BPSK

I need to write the row:
mapper = Mapper("pam", 1)

Am I correct?

[jhoydis]

Yes. This is all plain Python code. When you write num_bits_per_symbol = 1, it simply defines a variable named num_bits_per_symbol which is equal to one. If you do not use this variable anywhere, it has no impact.

So, you could also write

num_bits_per_symbol = 1
mapper = Mapper("pam", num_bits_per_symbol)

[yossefyossef]

Jacob, you are an excellent teacher!

[yossefyossef]

I did it, and now I got a new error message:

ValueError: Unsupported coderate (r<1/5).

I used the following parameters:
k= 1920
n= 16384
Code-rate R= 0.1171875

Do you have a solution for this case?

[SebastianCa]

This is related to discussion #110. Please ensure that the coderate r>1/3. In this case, you could reduce the code length n (e.g., by a factor of 4).

[yossefyossef]

I made the following attempts to run the LDPC for BPSK, and they gave an error messages.

Maybe you can help me?

Attempt #1:

k= 1920
n = 4800
Code-rate R= 0.4

Used the following row:
mapper = Mapper("pam", 1) #this is the added row

got the error message:
NameError: name 'num_bits_per_symbol' is not defined

Attempt #2:

k= 1920
n = 4800
Code-rate R= 0.4

Used the following rows:
num_bits_per_symbol = 1
mapper = Mapper("pam", num_bits_per_symbol)

got the error message:
AssertionError: num_bits_per_symbol must be a mutliple of 2

Can you please guide me how to run the simulation for BPSK? It seems that I am missing out something.

[jhoydis]

Hi,

Which version of Sionna are you using?
This line definitely works:

Mapper("pam", 1)

[yossefyossef]

I wrote this row as it:
Mapper("pam", 1)
And got the error:
NameError: name 'num_bits_per_symbol' is not defined

I am checking which Sionna version was installed..

[jhoydis]

Please do this in a clean notebook:

import sionna
from sionna.mapping import Mapper
print(sionna.__version__)
Mapper("pam", 1)

[yossefyossef]

I use Sionna version 0.11.0

[yossefyossef]

I run the suggested rows:
import sionna
from sionna.mapping import Mapper
print(sionna.version)
Mapper("pam", 1)

and got the following result:

C:\Anaconda3\envs\tf\python.exe C:\Users\modem\PycharmProjects\sionna_test1\test_Sionna_ver.py
0.11.0
2023-04-03 11:06:45.765661: I tensorflow/core/platform/cpu_feature_guard.cc:193] This TensorFlow binary is optimized with oneAPI Deep Neural Network Library (oneDNN) to use the following CPU instructions in performance-critical operations: AVX AVX2
To enable them in other operations, rebuild TensorFlow with the appropriate compiler flags.
2023-04-03 11:06:46.541939: I tensorflow/core/common_runtime/gpu/gpu_device.cc:1616] Created device /job:localhost/replica:0/task:0/device:GPU:0 with 6647 MB memory: -> device: 0, name: Quadro P4000, pci bus id: 0000:01:00.0, compute capability: 6.1

Process finished with exit code 0

[jhoydis]

It should work with Sionna 0.11. You can try upgrading to a later version.
I cannot reproduce your issue.