This work proposes a direct sequence spread spectrum transmitter with high transmission range and efficiency for audio signals. It is shown that by choosing high process gain for spread spectrum signal the data could reach a range of 55km in the 2.4GHz ISM band. By employing a light modulation scheme, we have a relaxed SNR requirement for having a low bit error rate (BER) which translates to re...

We address the design of opportunistic spectrum access (OSA) strategies that allow secondary users to independently search for and exploit instantaneous spectrum availability. The design objective is to maximize the throughput of secondary users while limiting the probability of colliding with primary users. Integrated in the joint design are three basic components: a spectrum sensor at the phy...

Cognitive Radio is gaining popularity and acceptance all over the world as an efficient way to utilise the limited wireless spectrum resources. Out of the many design requirements of Cognitive Radio such as spectrum sensing, spectrum allocation, power control etc., spectrum sharing is one of main challenges to ensure peaceful co-existence of the primary and secondary users. Since multiple users...

Increasing capacity demands in emerging wireless technologies are expected to be met by network densification and spectrum bands open to multiple technologies. These will, in turn, increase the level of interference and also result in more complex inter-technology interactions, which will need to be managed through spectrum sharing mechanisms. Consequently, novel spectrum sharing mechanisms sho...