TY - JOUR
T1 - Power control and beamforming for femtocells in the presence of channel uncertainty
AU - Oh, Dong Chan
AU - Lee, Heui Chang
AU - Lee, Yong Hwan
N1 - Funding Information:
Manuscript received June 1, 2010; revised September 30, 2010 and February 7, 2011; accepted May 6, 2011. Date of publication June 9, 2011; date of current version July 18, 2011. This work was supported in part by the Korea Communications Commission through the R&D Program, which is supervised by the Korea Communications Agency, under Grant KCA-2011-09913-04004. The review of this paper was coordinated by Prof. L.-L. Yang.
PY - 2011/7
Y1 - 2011/7
N2 - Femtocells that are installed in existing macrocellular networks form a two-tiered heterogeneous network, yielding an interference problem between the two layers. How we can mitigate the interference is of great concern for the deployment of femtocells. When the femto base station has perfect channel information, it can mitigate the interference through transmit power control and beamforming. However, it may not be feasible to get perfect channel information due to unavoidable impairments such as channel estimation, quantization, and feedback delay. In the presence of such channel uncertainty, we consider the combined use of transmit power control and beamforming for femtocells in heterogeneous wireless communication environments. By analyzing the effect of channel uncertainty parameters on the performance, we determine the transmit power level to provide the desired signal-to-interference-plus-noise ratio (SINR) of the indoor cell edge femtouser and the beam weight to maximize the output SINR of the macrousers and femtousers by mitigating interference in a collaborate manner. Finally, simulation results show that the proposed scheme is quite effective in the presence of channel uncertainty.
AB - Femtocells that are installed in existing macrocellular networks form a two-tiered heterogeneous network, yielding an interference problem between the two layers. How we can mitigate the interference is of great concern for the deployment of femtocells. When the femto base station has perfect channel information, it can mitigate the interference through transmit power control and beamforming. However, it may not be feasible to get perfect channel information due to unavoidable impairments such as channel estimation, quantization, and feedback delay. In the presence of such channel uncertainty, we consider the combined use of transmit power control and beamforming for femtocells in heterogeneous wireless communication environments. By analyzing the effect of channel uncertainty parameters on the performance, we determine the transmit power level to provide the desired signal-to-interference-plus-noise ratio (SINR) of the indoor cell edge femtouser and the beam weight to maximize the output SINR of the macrousers and femtousers by mitigating interference in a collaborate manner. Finally, simulation results show that the proposed scheme is quite effective in the presence of channel uncertainty.
KW - Channel uncertainty
KW - femtocell
KW - heterogeneous systems
KW - transmit beamforming
KW - transmit power control
UR - http://www.scopus.com/inward/record.url?scp=79960349518&partnerID=8YFLogxK
U2 - 10.1109/TVT.2011.2158615
DO - 10.1109/TVT.2011.2158615
M3 - Article
AN - SCOPUS:79960349518
SN - 0018-9545
VL - 60
SP - 2545
EP - 2554
JO - IEEE Transactions on Vehicular Technology
JF - IEEE Transactions on Vehicular Technology
IS - 6
M1 - 5871725
ER -