• Massimiliano Ricci
Beamforming and power control algorithms are investigated in intra-system spectrum sharing for LTE Advanced system (named as Flexible Spectrum Usage, FSU) context. FSU is considered to occupy scarce spectral resources opportunistically in order to increase the average spectral efficiency of the system and to provide less interference to the other system. So, to avoid interference to other systems, beamforming and power control algorithms are investigated and implemented in MATLAB. As a starting point, assuming perfect channel state information at the transmitter, single-user (SU) multiple input multiple output (MIMO) downlink beamforming is implemented to evaluate the link performance of the system. As a case study, a link-level simulator complying UTRAN Long Term Evolution (LTE) standard is considered. Moreover, two multi-user (MU) MIMO downlink with OFDM/SDMA access scheme, beamforming algorithms zero-forcing (ZF) and successive minimum mean square error (SMMSE) are investigated to evaluate performance of the system at link-level by averaging the bit error rates (BERs) and throughputs (THs) of all the candidate users. Dominant eigen transmission (DET) power algorithm is to applied to both to maximize the SNR at the receiver and to minimize the BER. Numerical simulation results show significant gains by 3dB to 5 dB, depending of the modulation using, and 3dB about, for the low SNR, for the considered system in terms of BER and TH, respectively, compared to the same considered system without beamforming. Other results show significant gains by 3 dB and 3 dB, in terms of BER and TH, respectively, comparing SMMSE to ZF beamforming algorithm.
SprogEngelsk
Udgivelsesdato2008
Antal sider98
Udgivende institutionAalborg University
ID: 14222510