Multi-Input Multi-Output antennas based Orthogonal Frequency-Division Multiplexing （MIMO-OFDM） has been chosen as the air interface technology for China＇s beyond 3G Time-Division Duplex （TDD） mobile system in the...Multi-Input Multi-Output antennas based Orthogonal Frequency-Division Multiplexing （MIMO-OFDM） has been chosen as the air interface technology for China＇s beyond 3G Time-Division Duplex （TDD） mobile system in the FUTURE research project. Channel estimation plays a key role on the performance of the MIMO-OFDM receiver. In this paper, we present five channel estimation algorithms and study their performance in a simulated beyond 3G TDD mobile system, Simulation results show that the adaptive 2D-LMS algorithm we proposed recently has the best performance when the signal to noise ratio is lower than 8 dB.展开更多
An outdoor propagation measurement campaign for beyond 3G （B3G） as well as a wide-band indoor measurement campaign have been performed recently in Beijing, China, in which the sounding signals are transmitted by an ...An outdoor propagation measurement campaign for beyond 3G （B3G） as well as a wide-band indoor measurement campaign have been performed recently in Beijing, China, in which the sounding signals are transmitted by an one-antenna base station and received by a two-antenna mobile receiver operated at 3.49～3.51 GHz bandwidth. Different scenarios： stationary line-of-sight （LoS）, stationary non-LoS （NLoS） scenarios, and dynamic NLoS are deliberately chosen in a classic urban environment and office environment. The initial results are presented in this article. Parameters including vector channel impulse response, path loss, rays number, excess delay spread etc. are extracted, analyzed, and briefly reported here.展开更多
In this paper, adaptive modulation with channel estimation in high-speed packet-based Orthogonal Frequency Division Multiplexing (OFDM) communication systems for beyond 3G are discussed. Different adaptive modulation ...In this paper, adaptive modulation with channel estimation in high-speed packet-based Orthogonal Frequency Division Multiplexing (OFDM) communication systems for beyond 3G are discussed. Different adaptive modulation and channel estimation methods are presented and compared, then those methods suitable for our intended application are chosen. Conclusions can be drawn from computer simulations that with proper selection of packet length and subband width, wide subband adaptive modulation with Least Square plus Discrete-time Fourier Transform (LS-DFT) channel estimation can give an acceptable performance with low complexity for channel with low Doppler shift and small path delay. Otherwise, narrow subband or subcarrier adaptive modulation together with LS-DFT plus Decision Directed (LS-DFT-DD) must be used.展开更多
基金This workis supported by China National"863"Project (2003AA12331004) , National Natural Science Foundation of China (60472070) .
文摘Multi-Input Multi-Output antennas based Orthogonal Frequency-Division Multiplexing （MIMO-OFDM） has been chosen as the air interface technology for China＇s beyond 3G Time-Division Duplex （TDD） mobile system in the FUTURE research project. Channel estimation plays a key role on the performance of the MIMO-OFDM receiver. In this paper, we present five channel estimation algorithms and study their performance in a simulated beyond 3G TDD mobile system, Simulation results show that the adaptive 2D-LMS algorithm we proposed recently has the best performance when the signal to noise ratio is lower than 8 dB.
文摘An outdoor propagation measurement campaign for beyond 3G （B3G） as well as a wide-band indoor measurement campaign have been performed recently in Beijing, China, in which the sounding signals are transmitted by an one-antenna base station and received by a two-antenna mobile receiver operated at 3.49～3.51 GHz bandwidth. Different scenarios： stationary line-of-sight （LoS）, stationary non-LoS （NLoS） scenarios, and dynamic NLoS are deliberately chosen in a classic urban environment and office environment. The initial results are presented in this article. Parameters including vector channel impulse response, path loss, rays number, excess delay spread etc. are extracted, analyzed, and briefly reported here.
文摘In this paper, adaptive modulation with channel estimation in high-speed packet-based Orthogonal Frequency Division Multiplexing (OFDM) communication systems for beyond 3G are discussed. Different adaptive modulation and channel estimation methods are presented and compared, then those methods suitable for our intended application are chosen. Conclusions can be drawn from computer simulations that with proper selection of packet length and subband width, wide subband adaptive modulation with Least Square plus Discrete-time Fourier Transform (LS-DFT) channel estimation can give an acceptable performance with low complexity for channel with low Doppler shift and small path delay. Otherwise, narrow subband or subcarrier adaptive modulation together with LS-DFT plus Decision Directed (LS-DFT-DD) must be used.
