Based upon quadratic polynomials over the finite field, a new class of frequency hopping sequences with large family size suitable for applications in time/frequency hopping CDMA systems, multi-user radar and sonar sy...Based upon quadratic polynomials over the finite field, a new class of frequency hopping sequences with large family size suitable for applications in time/frequency hopping CDMA systems, multi-user radar and sonar systems is proposed and investigated. It is shown that the new time/frequency hopping sequences have at most one hit in their autocorrelation functions and at most two hits in their crosscorrelation functions except for a special case, and their family size is much larger than the conventional quadratic hopping sequences. The percentage of full collisions for the new quadratic hopping sequences is discussed. In addition, the average number of hits for the new quadratic hopping sequences, quadratic congruence sequences, extended quadratic congruence sequences and the general linear hopping sequences are also derived.展开更多
The multi-carrier code division multiple access (MC-CDMA) system is extended to the coded MC-CDMA system. This system combine the channel error correcting coding (ECC) with MC-CDMA systems, thus sufficiently exploitin...The multi-carrier code division multiple access (MC-CDMA) system is extended to the coded MC-CDMA system. This system combine the channel error correcting coding (ECC) with MC-CDMA systems, thus sufficiently exploiting the excellent performance of ECC (especially Turbo code) under low SNR. The BER performance of the system in different channels is analyzed, and the simulation results are given.展开更多
基金the Scientific Research Fund of Southwestern University of FinanceEconomics and the National Natural Science Foundation of China (Grant No. 60572142)
文摘Based upon quadratic polynomials over the finite field, a new class of frequency hopping sequences with large family size suitable for applications in time/frequency hopping CDMA systems, multi-user radar and sonar systems is proposed and investigated. It is shown that the new time/frequency hopping sequences have at most one hit in their autocorrelation functions and at most two hits in their crosscorrelation functions except for a special case, and their family size is much larger than the conventional quadratic hopping sequences. The percentage of full collisions for the new quadratic hopping sequences is discussed. In addition, the average number of hits for the new quadratic hopping sequences, quadratic congruence sequences, extended quadratic congruence sequences and the general linear hopping sequences are also derived.
文摘The multi-carrier code division multiple access (MC-CDMA) system is extended to the coded MC-CDMA system. This system combine the channel error correcting coding (ECC) with MC-CDMA systems, thus sufficiently exploiting the excellent performance of ECC (especially Turbo code) under low SNR. The BER performance of the system in different channels is analyzed, and the simulation results are given.
