Path loss modelling and comparison based on the radio propagation measurement at 3.5GHz

Wideband IMT-Advanced mobile communication systems tend to operate in the high frequency bandsdue to a relatively large capacity available .Thus,Measurement and modelling methods of radio propaga-tion characteristics are proposed for the field test of Chinese 4th generation(4G)trial system.The mea-surement system is established for 3 .5GHz based on the sophisticated measurement instruments and thevirtual instrument technology.The characteristic parameters of radio propagation such as path loss(PL)exponent and shadow fading standard deviation are extracted from measurement data,which result in thepath loss model finally.The comparisons with other existing international models results validate our mea-surement in terms of path loss model .Based on the analysis of the existing extension model assumed forthe microwave frequency at 3 .5GHz,we find that the Stanford University Interim(SUI)model fits verywell with the measurement result in the hotspot scenario,while the COST 231 model is closer to the mea-surement result in the suburban scenario.This result provides a measurement-based channel reference forthe development of the future IMT-Advanced systems in China.

Triple-Polarized Multi-User Mimo-Idma System under Correlated Fading Channel

A multiple-input multiple-output interleave division multiple access (MIMO-IDMA) system with Triple Polarized Division Multiplexing (TPDM) is presented in this paper. The present methodology replaces three independent linearly polarized antennas with a single triple polarized antenna at both the transmitter and receiver. The users in the communication link are accommodated and separated using a user-specific interleaver combined with low rate spreading sequence. To eliminate the effects of multi-stream interference (MSI), minimum mean square error (MMSE) algorithm based on successive interference cancellation (SIC) Multi-user detection (MUD) technique is employed at the receiver. Furthermore, log-maximum a posteriori probability (MAPP) decoding algorithm is implemented at the mobile stations (MSs) to overcome the effects of multi-user interference (MUI) effects. The paper also evaluates the effects of coded MIMO-IDMA in the downlink communication by adopting the Stanford University Interim (SUI) and Long-term Evolution (LTE)channel model specifications. In comparison with the traditional uncoded system, the present solution considering turbo coded triple-polarized MIMO-IDMA system with iterative decoding algorithm provides better bit error rate (BER) with reduced signal to noise ratio (SNR). The simulation results also show that though the SNR requirement is higher for the proposed technique compared to the conventional uni-polarized antenna based MIMO-IDMA system, it gives the advantages of achieving higher data rate with reduced cost and space requirements in the context of a downlink (DL).

Synchronization in Wireless Networks for Practical MIMO-OFDM Systems

In this paper a frequency offset estimation technique for Wireless Local Area and Wireless Metropolitan Ar- ea Networks is presented. For frequency offset estimation, we have applied a low-complexity frequency offset estimator for simple AWGN channels to fading channels for MIMO-OFDM systems. Simulation results have shown that the performance of the proposed estimator is better than the low complexity frequency offset estimator designed for AWGN channels.