Hello Monisha,

The term user/node is a little ambiguous. By primary user node do you mean the primary transmitter ? Any primary node can act as transmitter or receiver depending on type of application and type of channel.

Usually in infrastructure based primary networks, there is a central base station/ transmission tower like entity. Here this central station is a primary transmitter transmitting on down-link primary channels. Hence the term node is not usually used for such base station like entities.  The primary receiver receives signals from these primary transmitters. The receivers may be receive only or they may send some information back on an up-link channel. When this receiver is sending info back to the base station, it essentially acts as a transmitter again, and the base station is a receiver on the up-link channel.

In both cases, the secondary nodes regardless of its location will sense some signal transmission. But I am not sure which distance you want. Please let me know. I may guide you accordingly.

Thanks

you can do that by making assumptions on the signal propagation model (the PU) of the primary transmitter. but if you want that the secondary user to know this distance you have to assume that many prior information are available at the SU which might not be realistic. Thanks

Hi Monisha,

Since you are using a multi-node wireless system, I would be tempted to try time-delay triangulation. If you can produce a sent of distance and angle vectors, you could compute the line-of-site distance between any two nodes. At the network edge, the accuracy would be degraded and if the number of nodes is small, the accuracy is also degraded.

Good luck,

Steve