High BER with comm.RayTracingChannel when MaxNumReflections is Set to 0

Hi,

I'm working on writing a code to evaluate BER using comm.RayTracingChannel. I'm referencing the example "Indoor MIMO-OFDM Communication Link Using Ray Tracing". In this example, when I set MaxNumReflections to 0, allowing only the direct path, the BER comes out to be close to 50%.

I don't understand why this happens. Realistically, in a chamber LOS environment, measuring BER should result in only a direct path and a very low BER. Why does the example produce such a high BER?

Any insights would be greatly appreciated.

Thanks.

[Umar]

Hi 현준 양,

Please see my comments below.

Realistically, in a chamber LOS environment, measuring BER should result in only a direct path and a very low BER. Why does the example produce such a high BER?

The communication link becomes more vulnerable to noise and distortion, which increases the likelihood of bit errors during transmission.

Realistically, in a chamber LOS environment, measuring BER should result in only a direct path and a very low BER. Why does the example produce such a high BER?

This is due to various factors such as noise, interference, channel impairments, and specific simulation parameters which could be contributing higher than expected BER values in the comm.RayTracingChannel.

Answer 1

[Aastha]

Hi 현준 양,

I see that you are referencing the example ‘Indoor MIMO-OFDM Communication Link using Ray Tracing’ and you are getting a high BER close to 50% in a LOS chamber environment.

I tried to reproduce the issue using the same example and observed that a high pathloss can result in high BER.

As the pathloss is high, it results in the transmitted bits being lost in the environment which leads to decoding errors and a high BER.

Please refer to the image below to see pathloss value of 56.5350 dB.

Hope this helps!