This paper investigates a peak to average power ratio （PAPR） reduction method in multicarrier code division multiple access （MC-CDMA） system. Variable code sets （VCS）, a spreading codes selection scheme, can imp...This paper investigates a peak to average power ratio （PAPR） reduction method in multicarrier code division multiple access （MC-CDMA） system. Variable code sets （VCS）, a spreading codes selection scheme, can improve the PAPR property of the MC-CDMA signals, but this technique requires an exhaustive search over the combinations of spreading code sets. It is observed that when the number of active users increases, the search complexity will increase exponentially. Based on this fact, we propose a low complexity VCS （LC-VCS） method to reduce the computational complexity. The basic idea of LC-VCS is to derive new signals using the relationship between candidature signals. Simulation results show that the proposed approach can reduce PAPR with lower comtational pucomplexity. In addition, it can be blindly received without any side information.展开更多
A structure was proposed for multiple-input-multiple-output multicarrier code divi- sion multiple access （MIMO MC-CDMA） uplink transmission system. Linear zero- forcing V-BLAST （ZF V-BLAST） algorithm and maximum r...A structure was proposed for multiple-input-multiple-output multicarrier code divi- sion multiple access （MIMO MC-CDMA） uplink transmission system. Linear zero- forcing V-BLAST （ZF V-BLAST） algorithm and maximum ratio combining （MRC） scheme was applied to the receivers. The average bit error rate （BER） expression was derived on condition that the number of receive antennas was larger than that of transmit antennas and it was verified by simulations. Numerical results show that the number of transmit and receive antennas, as well as the number of sub- carriers, all exert significant effects on the BER performance. The space diversity and frequency diversity show different abilities to improve the BER performance. The MIMO MC-CDMA system based on linear ZF V-BLAST algorithm is capable of achieving better BER performance than that of the conventional MC-CDMA system by reducing the number of transmit antennas or increasing the number of receive antennas.展开更多
文摘This paper investigates a peak to average power ratio （PAPR） reduction method in multicarrier code division multiple access （MC-CDMA） system. Variable code sets （VCS）, a spreading codes selection scheme, can improve the PAPR property of the MC-CDMA signals, but this technique requires an exhaustive search over the combinations of spreading code sets. It is observed that when the number of active users increases, the search complexity will increase exponentially. Based on this fact, we propose a low complexity VCS （LC-VCS） method to reduce the computational complexity. The basic idea of LC-VCS is to derive new signals using the relationship between candidature signals. Simulation results show that the proposed approach can reduce PAPR with lower comtational pucomplexity. In addition, it can be blindly received without any side information.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 60572036 and 50534060)the National High Technology Project of China (Grant No. 2007AA01Z259)the Open Research Fund of National Mobile Communications Research Laboratory, Southeast University (Grant No. W200703).
文摘A structure was proposed for multiple-input-multiple-output multicarrier code divi- sion multiple access （MIMO MC-CDMA） uplink transmission system. Linear zero- forcing V-BLAST （ZF V-BLAST） algorithm and maximum ratio combining （MRC） scheme was applied to the receivers. The average bit error rate （BER） expression was derived on condition that the number of receive antennas was larger than that of transmit antennas and it was verified by simulations. Numerical results show that the number of transmit and receive antennas, as well as the number of sub- carriers, all exert significant effects on the BER performance. The space diversity and frequency diversity show different abilities to improve the BER performance. The MIMO MC-CDMA system based on linear ZF V-BLAST algorithm is capable of achieving better BER performance than that of the conventional MC-CDMA system by reducing the number of transmit antennas or increasing the number of receive antennas.
