1 research outputs found
Steady-State Rate-Optimal Power Adaptation in Energy Harvesting Opportunistic Cognitive Radios with Spectrum Sensing and Channel Estimation Errors
We consider an opportunistic cognitive radio network, consisting of Nu
secondary users (SUs) and an access point (AP), that can access a spectrum band
licensed to a primary user. Each SU is capable of harvesting energy, and is
equipped with a finite size battery, for energy storage. The SUs operate under
a time-slotted scheme, where each time slot consists of three non-overlapping
phases: spectrum sensing phase, channel probing phase, and data transmission
phase. The AP feeds back its estimates of fading coefficients of SUs-AP link to
SUs. To strike a balance between the energy harvesting and the energy
consumption, we propose a parameterized power control strategy that allows each
SU to adapt its power, according to the feedback information and its stored
energy. Modeling the randomly arriving energy packets during a time slot as a
Poisson process, we establish a lower bound on the achievable sum-rate of
SUs-AP links, in the presence of both spectrum sensing and channel estimation
errors. We optimize the parameters of the proposed power control strategy, such
that the derived sum-rate lower bound is maximized, subject to an interference
constraint. Via simulations, we corroborate our analysis and explore spectrum
sensing-channel probing-data transmission trade-offs.Comment: This paper has been submitted to IEEE Transactions on Green
Communications and Networkin