Xiaoying Sun

Combined beamforming and space-time block coding for wireless communications

This paper presents un approach for beamforming based on third-order cyclic statistics. The approach has fairly well accuracy. Further, a new scheme joint beamforming and space-time block coding is suggested that multiple antenna arrays transmit at base station and multi-antenna elements receive at mobile terminal. This scheme improves the receiving error performance of mobile terminal and increases the capacity of the entire wireless communication system. The computer simulation validates that the aforementioned scheme is superior and effective.

A frequency diversity scheme for OFDM systems based on space-time block coding

In this paper, a frequency diversity scheme for space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) systems is investigated. The scheme can simultaneously obtain frequency diversity and space diversity gain. Extensive simulations show that the proposed scheme with two transmit antennas and a single receive antenna almost has the same performance as STBC-OFDM systems with four transmit antennas and a single receive antenna. Under the same symbol error rate (SER) performance, the number of transmit antenna is not required to be increased because of using frequency diversity.

Joint downlink beamforming and space-time block coding for DS-CDMA systems in frequency selective fading channel

A downlink beamforming combined space-time coding and power control scheme for DS-CDMA systems in frequency selective fading channel is presented in this paper, in which the space-time coding is implemented by using two array antennas and the beamforming weights and transmitted power vector are obtained by an iterative algorithm such that the whole radiated power is minimized while the signal-to-interference and noise (SINR) requirements is maintained. Then a simplified algorithm for decreasing the complexity due to the existence of multipaths is suggested using equivalent one-path channel vector (EOCV) to replace multipath vectors. Simulations compare the performance between conventional space-time coding scheme and our method.

An adaptive interleaving scheme for MIMO-OFDM systems

In this paper, an adaptive interleaving scheme for multiple-input and multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems is proposed. The scheme could better exploit the instantaneous channel variation by rearranging the transmitted symbols according to the quasiinstantaneous channel SNR of the OFDM frame. The purpose is to break up a long burst channel error so that overall bit error probability is reduced. Extensive simulations show that significant SNR can be obtained with the proposed scheme and the MIMO-OFDM case has a performance improvement over the single antenna case. Compared with block interleaving, for 2Tx-2Rx case at a BER of 10/sup -/2, adaptive interleaving offers a 5dB improvement.

Harmonics retrieval based on quaternion matrix

This paper presented a novel method to estimate harmonicspsila parameters with quaternion. First, a kind of quaternion model of harmonic was established. Then, its correlation matrix, a quaternion correlation matrix (QCM), was constructed. Finally, this QCM was decomposed, where quaternion noise subspace was used to estimate harmonicpsilas parameters. Simulations illustrated this special idea and showed that frequency resolution of this method was better than that of classical MUSIC method.

Performance of Space-Time Trellis coding for TH-UWB-IR Systems

In this paper, we discuss the design of STTC for TH-UWB-IR systems with different modulations. The performances of these STTC schemes are evaluated under various conditions such as multipath and multiuser through simulations. The results show that STTC-UWB with PPM can achieve much better performance than the schemes employing PAM and biorthogonal modulation. Furthermore, we find the performance degrades when the number of users increases

Virtual uplink beamforming and power control for space-time coding scheme in DS-CDMA systems with two array antennas

Virtual uplink beamforming and power control technique (V-UBPCT) is an effective means for improving downlink performance in DS-CDMA systems. We present a modified V-UBPCT algorithm for block space-time coding scheme with two array antennas, in which the downlink beamforming weight and transmitted power vectors are generated iteratively when the total transmitted power is minimized while received signal-to-interference-and-noise (SINR) requirements are maintained. Simulations compare the total transmitted power and SINR between conventional orthogonal space-time coding scheme and our method.

Beam space-time block coding with beamforming based on cyclic statistics for wireless communications

This paper presents an approach for beamforming based on third-order cyclic statistics. The approach has fairly well accuracy. Further, a new scheme joint beamforming and space-time block coding is suggested that dual antenna arrays transmit at base station and multi-antenna elements receive at mobile terminal. This scheme improves the receiving error performance of mobile terminal and increases the capacity of the entire wireless communication system. The computer simulation validates that the aforementioned scheme is superior and effective.