Conference Paper

Joint Beamforming and Power Control Algorithm for Cognitive Radio Network with the Multi-Antenna Base Station

DOI: 10.1109/WCNC.2010.5506457 Conference: Wireless Communications and Networking Conference (WCNC), 2010 IEEE
Source: IEEE Xplore


Cognitive radio (CR) has been studied as a useful solution for efficient utilization of scarce radio spectrums. For it to succeed, two conflicting challenges are imposed on the secondary users: one is to ensure the quality of service (QoS) of the primary link, and the other is to maximize their own transmit throughput. To balance this tradeoff, beamforming and power control employing the multi-antenna in the base station (BS) of the CR network have been introduced. In the perfect beamforming situation, the power control algorithms suitable in the CR network with a multi-antenna BS (MBS) have been proposed in previous works. However, those algorithms are meaningless for realizing a practical CR network with the MBS since perfect beamforming is impossible. Therefore, unlike previous works, this paper proposes a joint beamforming and power control algorithm as a more practical strategy for realizing a CR network with the MBS. The algorithm is proposed so as to maximize the sum-rate of secondary users, while not degrading QoS for the primary link. Numerical results verify its effectiveness in a CR network with the MBS.

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    • "[4], transmit beamforming (TB) is designed for MIMO cognitive radio networks in a single primary user-(PU-) single secondary user (SU) network, to minimize the transmit power of the SU while limiting the interference temperature to PU and achieving the signal-to-interference-plus-noise ratio (SINR) target at SU. The joint problem of TB and power control in CRN have been considered in [5] [6], where the objective is to optimize the SU users sum rate under the interference constraints of PUs. The joint problems of TB at transmitter and antenna subset selection at receiver of a secondary network are considered in [7], where TB is recruited at multiantenna secondary transmitter to maximize the data rates in SU link; meanwhile the interference on PUs is minimized. "
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    ABSTRACT: An approach for beamforming with reduced complexity in MIMO cooperative cognitive radio networks (MIMO-CCRN) is presented. Specifically, a suboptimal approach with reduced complexity is proposed to jointly determine the transmit beamforming (TB) and cooperative beamforming (CB) weight vectors along with antenna subset selection in MIMO-CCRN. Two multiantenna secondary users (SU) constitute the desired link, one acting as transmitter (SU TX) and the other as receiver (SU RX) and they coexist with single-antenna primary and secondary users. Some of single antenna secondary users are recruited by desired link as cooperative relay. The maximization of the achievable rates in the desired link is the objective of this work, provided to interference constraints on the primary users are not violated. The objective is achieved by exploiting transmit beamforming at SU TX, cooperation of some secondary users, and cooperative beamforming. Meanwhile, the costs associated with RF chains at the radio front end at SU RX are reduced. Through simulations, it is shown that better performance in the desired link is attained, as a result of cooperation of SUs.
    Full-text · Article · May 2014
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    ABSTRACT: The downlink beamforiming technology plays a key role in a cognitive radio network (CR-Net). It can be used to reduce transmission power and interference to other users, etc. This paper presents a robust downlink beamforming method with power control for a multiuser multiple-input-single-output (MISO) CR-Net. In this proposed approach, the beamforming optimization problem is formulated as the second-order cone programming (SOCP). The presented method can not only minimize the transmitted power but also guarantee that the received signal-to-interference-plus-noise ratio (SINR) is strictly above the prescribed quality-of-service (Qos)-constrained threshold at each secondary user (SU) and the the interference power (IP) is strictly below the prescribed threshold at the primary user (PU). Simulation results are presented to verify the efficiency of the proposed method.
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    ABSTRACT: The main target of a 60 GHz transceiver system is to obtain data rates close to gigabit per second over short distances. The 60 GHz band suffers from severe path-loss, inter-symbol interference (ISI) and a limited link budget. To improve the link budget, we need to utilize beam-forming (BF) techniques. Antenna BF, i.e., combining signals from multiple receive antennas is one of the crucial aspects of the 60- GHz transceiver system. We consider uniform linear and circular antenna arrays for the proposed BF scheme. We use single carrier with frequency domain equalization (SC-FDE) modulation scheme in our system model. To suppress the ISI, we considered a cyclic prefix in the SC-FDE. The effects of physical parameters of antenna arrays on the bit error rate (BER) were investigated assuming both line of sight (LOS) and non-line of sight scenarios. We developed an efficient and computationally less complex beam-forming algorithm (BFA). We investigated the effects of perfect channel and non-perfect channel on the BER performance using the proposed BFA. We presented that the BER and sever ISI of 60 GHz band also improves using the proposed BFA.
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