将阵列天线应用于多载波CDMA系统可以显著改善系统的性能,讨论了3种阵列天线多载波CDMA系统发射、接收信号和信道模型,给出了系统的误码率公式.分析了3种阵列天线多载波CDMA系统在频谱效率相同时的系统参数.在频谱效率相同的条件下,通过数值结果比较了3种阵列天线多载波CDMA系统的误码率性能.结果表明,阵列天线MC-CDMA系统由于受空域和频域分集的联合影响,系统的误码率性能最好;阵列天线MT—CDMA系统可获得空域和时域分集增益,系统性能次之;阵列天线MC-DS-CDMA系统只有空域分集增益,系统性能相对最差.
The performance of the three typical muhi-carrier CDMA systems can be improved significantly by applying antenna array. The transmitted signals, received signals and channel models of the multi-carrier CDMA systems with antenna array are discussed, and the bit error rate (BER) formulas of the three systems are provided. The parameters are analyzed and the BER performances are com- pared for the three systems under the condition of the same spectral efficiency. Numerical results indicate that the antenna array MC-CDMA performs best for the joint space and frequency diversity gain; antenna array MT-CDMA takes the second place for the joint space and time diversity gain; and antenna array MC-DS-CDMA performs the worst among the three systems since only the space gain can be obtained for this scheme.