In the attached figure A and B are transmitting to some destination X and Y (not shown in the figure) using transmit power TxA and TxB respectively. Where node C wants to transmit to node D.
Assuming that the distance between all the nodes is known, I want to find the following.
1. The total received power at node D due to the transmissions from node A and node B
combined i.e. total interference.
2. We assume that SINR threshold for successful decoding is Th. What should be the transmit
power of C i.e. TxC , so that its signal can be successfully decoded at node D in the presence
of interference from node A and B
3. How to calculate SINR and BER at node D for the signal transmitted by node C.
Thanks
Hi,
prior to post a relevant answer, can you confirm that your question rely to underwater transmission or atmospheric ?
Dear Tariq Islam ,
Assuming that the transmission coefficients of the channels from the A and B to node C are ha and hb and assume that the transmit signal of A is Sa and that of B is Sb then the received signal at node C rC= ha Sa + hb SB
The power received is rC^2.
This power can be considered an interference which is added to the white noise to determine the threshold of the useful received signal.
So the total noise at the node C= rC^2 +N
The required signal to noise ratio is then given by
C= B log2 (1 + S/( rC^2 +N))
where S is the useful recieved signal power at node C received from the intended node. Bis the bandwidth and C is the maximum bit rate.
Best wishes
in addition to M. Zekry details:
we understand ha and hb to be the free space loss between concerned sites
Sa is the radiation power density in direction to the interferred site so btw if antenna is directional, radiation pattern shall be taken into account.
thenyou shall consider all potential interferers in the coordination region (region where potential intefrerrers are located.
and of sure if interferer is transmitting in a separate channel, spectrum PSD of the transmitter and Receiver front end selectivity shall be also introduced in the final computation.
best regards, Pierre
Abdelhalim abdelnaby Zekry I can calculate received signal power(RAC) at receiver C, when "one" particular transmitter A is transmitting using transmit power PA as follows:
RAC=PA - Pathloss (Antenna gains ignored for simplicity)
My confusion is as follows:
If RAC is the received power at node C when only node A is transmitting, What will be the total received power at node C when node B is also transmitting at the same time. Will it be simply RAC+RBC i.e. is the following equation true?
Total received power = RAC+RBC
( Where RBC is the power received at node C when only node B is transmitting)
If not, please suggest a solution in terms of transmit powers, pathloss and received power.
Best regards
Usually received power level qualify the waited signal and the other signal is considered as interferer so it contributes to degrade the receiver fade margin.
if now you look at RSL indicator, it will report the total received power (waited + interferer).
best regards, Pierre
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