Power Amplitude of PRBS Generator

[Fauza Khair]

Dear All,

Please give me explanation about PRBS generator. We can set bit rate, order and number leading and trailing zeros in simulation.. How much (dBm) the power output of PRBS ? can we set the power output on PRBS ? or PRBS not have spesification the power amplitude ?

Thank

[Alessandro Festa]

Hi, that component is just a bit generator…so I don’t think that talking of dBm power for its output makes sense.

[Fauza Khair]

Thank Mr Alessandro Festa.. So, PRBS only generates the bit sequences, the value is true (1) or false (0), isn’t it ?

When the output PRBS is connected to QAM Sequence generator and then both of QAM Sequence outputs are connected to OFDM, we can measurement the electrical power in output of OFDM.. I have some difference power value if i use 4 QAM and 16 QAM. Please give me explanation, where the power in step could be present ? from QAM or OFDM ?

Thank you before,

[Alessandro Festa]

Yes, PRBS only generates 1 and 0.
It is better if you attach your design to comment the issue you are seeing.

[Fauza Khair]

Thank you Mr Alessandro Festa..
Please try if bits per symbol = 2 or 4 bits.

Regard,

Fauza

Attachments:

1. coba.osd

[gaganpreet Kaur]

As per my knowledge by default system is set to 2 symbols per bit u can try and change the values scripted in ‘order’ and bit rate of PRBS

[Ashu verma]

Hello,Fauza khair
Alessandro said correct that PRBS is used to transmit random sequence of 0 & 1 and there is no power associated with PRBS. Now according to your second question about using 4QAM and 16QAM , that power change associated in OFDM system. According to my knowledge , 4QAM and 16QAM referred to 2 Bits/symbol and 4 Bits/ symbol respectively. 16QAM is different to 4QAM in the way that it is more bandwidth efficient and capable to transmit more data. However, using 16QAM increases noise level in OFDM system. I don’t think by using 4QAM or 16QAM there will be any change in power associate to it.

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