On the capacity of Rayleigh-fading correlated spectrum sharing networks

Abstract

Recently, substantial attention has been paid to improve the spectral efficiency of communication setups using different spectrum sharing techniques. This paper aims to study the capacity of Rayleigh-fading spectrum sharing channels in the case where there is correlation between the fading channels. Assuming perfect channel state information, the channel capacity is obtained under both adaptive and nonadaptive unlicensed user power allocation capabilities and the licensed user outage probability and received interference power constraints. Theoretical and simulation results show that (1) there is considerable potential for data transmission of unlicensed users with limited degradation of the licensed users' data transmission efficiency, (2) while the effect of fading channels dependencies is ignorable at low correlation values, the channel capacity is significantly affected as the channels correlation increases, and (3) depending on the fading distributions, the unlicensed user channel capacity is not essentially a decreasing function of the licensed user transmission power in the licensed user outage-limited scenario.

Interference-free spectrum sharing using a sequential decoder at the primary user

“…This is in contrast to the previously proposed schemes [11]- [20], where the PU received interference constraints are satisfied by power allocation at SU transmitter which, due to power amplifiers nonlinearity, is not practically feasible. Finally, among practical coding schemes providing the rate adaptation requirements, we can mention, e.g., [28]- [31].…”

“…Moreover, there is no need for power allocation where the data transmission is done at fixed power simplifying the power amplifier designing problem. Finally, in contrast to simple decoder-based schemes [11]- [20], spectrum sharing leads to higher network sum rate when sequential decoders are utilized.…”

“…For instance, considering different primary or secondary user power constraints, [11]- [14] investigated the SU achievable rates under full channel state information (CSI) assumption. These works were later extended by e.g., [15]- [20] where the secondary channel performance was analyzed under different SU transmitter knowledge imperfection conditions.…”

“…Considering, e.g., [3]- [5], [11]- [20], there are three points motivating this paper: 1) in many recently developed spectrum sharing techniques the presence of the SU is at the cost of the PU received interference increment, as using simple decoders the SU signal is treated as an additive noise in the PU receiver. However, this is not acceptable for many license holders, as the interference deteriorates their data transmission efficiency, although it is tried to be kept limited.…”

Water-filling for full-duplex multiple-hop MIMO relay system

“…According to transmission of MIMO schemes, a channel capacity of system was improved. Moreover, the allocation of transmit power for each antenna based on channel model, meaning water-filling (WF), also has been applied to improve the channel capacity of MIMO systems [5][6][7][8].…”