Changhyeon Chae

Design of New Quasi-Orthogonal STBC with Minimum Decoding Complexity for Four Transmit Antennas

A new Space-Time Block Code (STBC) achieving full rate and full diversity for general QAM and four transmit antennas is proposed. This code also possesses a quasi-orthogonal (QO) property like the conventional Minimum Decoding Complexity QO-STBC (MDC-QO-STBC), leadingg to joint ML detection of only two real symbols. The proposed code is shown to exhibit the identical error performance with the existing MDC-QO-STBC. However, the proposed code has an advantage in transceiver implementation since this code can be modified so that the increase of PAPR occurs on only two transmit antennas, whereas MDC-QO-STBC incurs a PAPR increase on all transmit antennas.

New Minimum Decoding Complexity Quasi-Orthogonal Space-Time Block Code for 8 Transmit Antennas

In this paper, a new full-rate space-time block code (STBC) possessing a quasi-orthogonal (QO) property is proposed for QAM and 8 transmit antennas. This code is designed by serially concatenating a real constellation-rotating precoder with the Alamouti scheme. The QO property enables a maximum likelihood (ML) decoding to only require joint detection of four groups of real symbols at a receiver. Hence, this code has an identical and greatly reduced ML decoding complexity with the conventional minimum decoding complexity QO-STBC (MDC- QO-STBC) and the Xians QO-STBC, respectively. Especially, the proposed QO-STBC is guaranteed to enjoy full diversity for general QAM unlike the existing MDC-QO-STBC presented for only QPSK. By simulation results, we show that the proposed code exhibits the identical and slightly degrade error performance with the existing MDC-QO-STBC for 4-QAM and the Xians QO-STBC for 4 and 16-QAM, respectively.

Design of New Minimum Decoding Complexity Quasi-Orthogonal Space-Time Block Code for 8 Transmit Antennas

In this paper, a new full-rate space-time block code (STBC) possessing a quasi-orthogonal (QO) property is proposed for QAM and 8 transmit antennas. This code is designed by serially concatenating a real constellation-rotating precoder with the Alamouti scheme. The QO property enables a maximum likelihood (ML) decoding to only require joint detection of four groups of real symbols at a receiver. Hence, this code has an identical and greatly reduced ML decoding complexity with the conventional minimum decoding complexity QO-STBC (MDC- QO-STBC) and the Xians QO-STBC, respectively. Especially, the proposed QO-STBC is guaranteed to enjoy full diversity for general QAM unlike the existing MDC-QO-STBC presented for only QPSK. By simulation results, we show that the proposed code exhibits the identical and slightly degrade error performance with the existing MDC-QO-STBC for 4-QAM and the Xians QO-STBC for 4 and 16-QAM, respectively.

New Delay Optimum Quasi-Othogonal Space-Time Block Codes with Full Spatial Diversity

In this paper, we propose a novel, systematic structure for quasi-orthogonal space-time block codes (QO-STBCs) achieving full rate for even number of transmit antennas over quasi-static Rayleigh fading channels. Especially, the new codes are delay optimal unlike conventional QO-STBCs and thus have a great advantage in ML decoding complexity at a receiver. In order to exploit full spatial diversity, we utilize a constellation rotation method and also examine optimal rotation angles through brute-force search for some cases of modulations and transmit antennas. Computer simulation results show that the proposed codes exhibit average error performance almost the same as or better than the existing QO-STBCs.

Design of new minimum decoding complexity quasi-orthogonal Space-Time Block Code for four transmit antennas

A new space-time block code (STBC) achieving full rate and full diversity for general QAM and four transmit antennas is proposed. This code also possesses a quasi-orthogonal (QO) property like the conventional minimum decoding complexity QO-STBC (MDC-QO-STBC), leading to joint ML detection of only two real symbols. The proposed code is shown to exhibit the identical error performance with the existing MDC-QO-STBC. However, the proposed code has an advantage in the transceiver implementation since this code can be modified so that the increase of PAPR occurs at only two transmit antennas, but the MDC-QO-STBC at all of transmit antennas.

Performance Analysis of Adaptive Modulation System with Optimal Turbo Coded V-BLAST Technique corresponding to each MIMO

In this paper, we propose and analyze an adaptive modulation system with optimal turbo coded V- BLAST (vertical-bell-lab layered space-time) technique that adopts the extrinsic information from MAP (maximum a posteriori) decoder with iterative decoding as a priori probability in two decoding procedures of V-BLAST scheme; the ordering and the slicing. Also, we consider and compare The adaptive modulation system using conventional turbo coded V-BLAST technique that is simply combined V-BLAST scheme with turbo coding scheme and that is decoded by the ML(maximum likelihood) decoding algorithm. In addition, we apply MIMO (multiple input multiple output) schemes to the systems for more performance improvement. The result indicates that the proposed systems achieve a better throughput performance than the conventional systems in the whole SNR range. And in terms of the throughput performance, the suggested system is close proximity to the conventional system using the ML decoding algorithm. In addition, the simulation result shows that the maximum throughput improvement in each MIMO scheme is respectively about 350 kbps, 460 kbps, and 740 kbps. It is suggested that the effect of the proposed decoding algorithm accordingly gets higher as the number of system antenna increases.