In this paper, we present a novel group space-time block coding slow frequency-hopping multicarrier direct-sequence code division multiple access (GSTBC SFH/MC DS-CDMA) system over frequency selective fading channels....
详细信息
In this paper, we present a novel group space-time block coding slow frequency-hopping multicarrier direct-sequence code division multiple access (GSTBC SFH/MC DS-CDMA) system over frequency selective fading channels. The proposed scheme greatly improves the bandwidth-efficient through assigning the users employing the same frequency-hopping (FH) pattern. Moreover, the users employing the same FH pattern are assigned into different virtual groups, in which the users are assigned to the different spreading codes, while the users are assigned to the same spreading code in the same virtual group. Then, a novel group detection scheme that we denote by group ordered successive interference cancellation (GOSIC) is presented to suppress the interference between the different virtual groups. Our proposed scheme consists of ordering group at the receiver side in order to maximize the overall system performance, and carrying BLAST-STBC (LSTBC) detection for the users in the same virtual group. We define and derive the optimal group order based on the post group signal to interference plus noise ratio (PGSINR). We also propose another suboptimal group order in order to overcome the complexity issues. Finally, we compare the performance of our proposed GOSIC with conventional group successive interference cancellation (GSIC), conventional STBC multiuser detection (MUD), and LSTBC-MUD, and show that significant improvement is introduced. Finally, it is shown that the proposed scheme is robust to the imperfect channel estimation. Copyright (C) 2006 John Wiley & Sons, Ltd.
Antenna diversity is an effective technique for improving the transmission performance in a multi-path fading channel. Recently, transmit diversity has been attracting much attention since it can alleviate the complex...
详细信息
Antenna diversity is an effective technique for improving the transmission performance in a multi-path fading channel. Recently, transmit diversity has been attracting much attention since it can alleviate the complexity problem of the mobile terminals. Joint transmit diversity/receive diversity achieves a much improved transmission performance. In this paper, we propose a new space-time block coding algorithm for joint transmit/receive diversity, which requires the channel state information (CSI) only at the transmitter side. Unlike the conventional space-time transmit diversity (STTD), the space-timeblock coded joint transmit/receive diversity (STBC-JTRD) can use. arbitrary number of transmit antennas, while the number of receive antennas is limited to 4. STBC-JTRD achieves a larger diversity gain than joint STTD/receive antenna diversity. The bit error rate (BER) analysis in a frequency-nonselective Rayleigh fading channel is presented. The BER performance is evaluated and is confirmed by the computer simulation.
In this letter we evaluate the system performance of a space-timeblock coded (STBC) multicarrier (MC) DS-CDMA system over a time selective fading channel, with imperfect channel knowledge. The average bit error rate ...
详细信息
In this letter we evaluate the system performance of a space-timeblock coded (STBC) multicarrier (MC) DS-CDMA system over a time selective fading channel, with imperfect channel knowledge. The average bit error rate impairment due to imperfect channel information Is investigated by taking into account the effect of the STBC position. We consider two schemes: STBC after spreading and STBC before spreading in the MC DS-CDAM system. In the scheme with STBC after spreading, STBC is performed at the chip level;in the scheme with MC before spreading, STBC is performed at the symbol level. We found that these two schemes have various channel estimation errors, and that the system with STBC before spreading is more sensitive to channel estimation than the system with STBC after spreading. Furthermore, derived results prove that a high spreading factor (SF) in the MC DS-CDAM system with STBC before spreading leads to high channel estimation error whereas for a system with STBC after spreading this statement is not true.
For a multiple-input-single-output (MISO) communications system, we take the presence of the erroneous channel state information (ECSI) into consideration. Multiple transmit antennas selection (TAS) over NUSO systems ...
详细信息
ISBN:
(纸本)9781424408009
For a multiple-input-single-output (MISO) communications system, we take the presence of the erroneous channel state information (ECSI) into consideration. Multiple transmit antennas selection (TAS) over NUSO systems with space-time block coding (STBC) (TAS/STBC) is investigated, and a solution over order statistic characteristic of the selective channel with ECSI is proposed. A more accurate analytical expression of Chernoff upper bound (CUB) bit-error rate (BER) for Binary Phase-Shift Keying (BPSK) modulation is derived in flat Rayleigh fading channel. Finally, both CUB BER values and true BER ones with simulation show that TAS technique can improve obviously system transmission performance and mitigate effectively effects of the ECSI.
Metrics obtained from a set of channel measurement data are used to predict performance of different MIMO techniques, such as spatial multiplexing and space-time block coding. For a given channel realisation, metries ...
详细信息
ISBN:
(纸本)9781424400379
Metrics obtained from a set of channel measurement data are used to predict performance of different MIMO techniques, such as spatial multiplexing and space-time block coding. For a given channel realisation, metries such as mutual information, eigenvalues, etc. can be extracted and the BER performance simulated for different MIMO techniques. By correlating the simulated BER performances to the metrics, it can be determined which metrics are useful BER performance predictors for a given MIMO technique. It is shown that mutual information and the eigenvalues of the spatial correlation matrix are useful BER predictors for V-BLAST and STBC techniques.
Trellis coded modulation (TCM) is a bandwidth efficient transmission scheme that can achieve high coding gain by integrating coding and modulation. This paper presents an analytical expression for the error event prob...
详细信息
Trellis coded modulation (TCM) is a bandwidth efficient transmission scheme that can achieve high coding gain by integrating coding and modulation. This paper presents an analytical expression for the error event probability of concatenated space-time block coding with TCM which reveals some dominant factors affecting the system performance over slow fading channels when perfect interleavers are used. This leads to establishing the design criteria for constructing optimal trellis codes of such concatenated system over slow flat fading channels. Through simulation, significant performance improvement is shown to be obtained by concatenating the interleaved streams of these codes with space-timeblock codes over fading channels. Simulation results also demonstrate that these trellis codes have better error performance than traditional codes designed for single-antenna Gaussian or fading channels. Performance results over quasi-static fading channels without interleaving are also compared in this paper. Furthermore, it is shown that concatenated. space-time block coding with TCM (with/without interleaving) outperforms space-time trellis codes under the same spectral efficiency, trellis complexity, and signal constellation.
The space-time block coding (STBC), as animportant member of the space-timecoding family, has recentlybeen developed to take advantage of the substantial capacityincreases which are available in MIMO wireless systems...
详细信息
The space-time block coding (STBC), as animportant member of the space-timecoding family, has recentlybeen developed to take advantage of the substantial capacityincreases which are available in MIMO wireless systems. Afterthe introduction of space-timecoding, the channel model of theMIMO is presented for STBC. Then the encoding and decodingalgorithm under QAM constellation for STBC are ***, the simulation results for various STBC under QAMmodulation are figured out.
An optimal minimum mean square error successive interference cancellation (OMMSE SIC) scheme for Groupwise space-time block coding (G-STBC) multiple-input multiple-output (MIMO) systems is presented. In such a system,...
详细信息
An optimal minimum mean square error successive interference cancellation (OMMSE SIC) scheme for Groupwise space-time block coding (G-STBC) multiple-input multiple-output (MIMO) systems is presented. In such a system, transmit antennas are partitioned into several STBC encoding groups and each group transmits independent data stream which is individually STBC encoded. On the receiver side, by exploring the temporal constraint provided by STBC, an equivalent channel model similar to the one in standard vertical Bell laboratories layered space-time (VBLAST) systems is generated. Then OMMSE SIC algorithm is performed to detect all the transmitted *** compares the proposed scheme with non-ordering MMSE SIC scheme and the corresponding equal data rate scheme in V-BLAST systems with the same receive antennas' number. Result shows that the proposed scheme has better performance than non-ordering MMSE SIC scheme and by introducing more transmit antennas and adopting the OMMSE SIC scheme, better performance also can be achieved than corresponding V-BLAST systems.
In this paper, a novel space-time-frequency minimum mean squared error (STF-MMSE)-based parallel interference cancellation receiver is proposed for space-timeblock-coded multicarrier code division multiple access sys...
详细信息
In this paper, a novel space-time-frequency minimum mean squared error (STF-MMSE)-based parallel interference cancellation receiver is proposed for space-timeblock-coded multicarrier code division multiple access systems in time-varying fading channels. The, signal processing of this new detector is jointly implemented in space, time, and frequency domains, which leads to a powerful capability of combating interference coming from different sources. An adaptive implementation based on subspace estimation is proposed for slow-varying fading channels. Furthermore, based on the characteristic function of a complex Gaussian random vector, an analytical method to calculate the bit error probability of the proposed STF-NMSE receiver is presented. Representative examples of the detector are provided to demonstrate its superior performance.
A reconfigurable space-timecoding technique is investigated, for a high-speed downlink packet access multiple-antenna network, which combats the effects of antenna correlation. Reconfigurability is achieved at the li...
详细信息
A reconfigurable space-timecoding technique is investigated, for a high-speed downlink packet access multiple-antenna network, which combats the effects of antenna correlation. Reconfigurability is achieved at the link level by introducing a linear precoder in a space-timeblock coded system. The technique assumes knowledge of the long-term characteristics of the channel, namely the channel correlation matrix at the transmitter. The benefits of the proposed reconfigurable technique as compared to the conventional non-reconfigurable versions are evaluated via system-level simulations. In order to characterize the system-level performance accurately and, at the same time, use a feasible approach in terms of computational complexity, a suitable link-to-system interface has been developed. The average system throughput and the number of satisfied users are the performance metrics of interest. Simulation results demonstrate the performance enhancements achieved by the application of reconfigurable techniques as compared to their conventional counterparts.
暂无评论