| 摘要: |
| 为了提高双选择性衰落信道下滤波多音（FMT）多载波系统的性能，从子载波调制角度出发，提出了一种连续相位调制-滤波多音（CPM-FMT）联合调制方法。该方法首先将比特数据流串并转换后进行CPM映射，接着对映射后的信号进行重组，然后进行FMT调制。在接收端首先将接收的信号进行FMT解调并进行逆重组，然后进行CPM解映射恢复出比特数据流。实验结果表明，CPM-FMT联合调制方法优于传统调制的QPSK-FMT方法，在误码率为10-3时，白噪声信道下性能最大提高了10 dB，时间频率双选择性衰落信道下性能提高了5 dB，同时该方法对多谱勒频偏具有良好的稳健性。这表明CPM-FMT方法能显著提高FMT系统在双选择性衰落信道下的性能，可应用于高速移动环境下的宽带无线传输系统。 |
| 关键词: 宽带无线传输 滤波多音 连续相位调制 联合调制 双选择性衰落 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目（61461015）；广西自然科学基金资助项目(2015GXNSFAA139302)；桂林电子科技大学研究生教育创新计划资助项目(2016YJCX75) |
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| A hybrid CPM-FMT modulation scheme in doubly selective fading channels |
| GAN Zixing,XIE Yuelei,NONG Qianwen |
| (School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,China) |
| Abstract: |
| In order to improve the performance of Filtered Multitone(FMT) multi-carrier systems under doubly selective fading channels,a Continuous Phase Modulation-Filtered Multitone(CPM-FMT) hybrid modulation method is proposed by applying a CPM scheme to the subcarriers of FMT symbols.In the proposed method,the serial bit stream is converted into a parallel bit stream and mapped to an appropriate complex signal according to the CPM scheme.Then the complex signal is reshaped to perform the FMT modulation.At the receiver,the received signal is inversely reshaped after being processed by a FMT demodulator,and the original bit stream is extracted by a CPM de-mapper.The simulation results show that the CPM-FMT method outperforms the traditional QPSK-FMT method in bit error rate(BER) performance.When the BER is 10-3,the performance is increased 10 dB and 5 dB in the white noise channels and time-frequency selective fading channels,respectively.At the same time,the proposed method is very robust to Doppler offset.It means that the CPM-FMT method can significantly improve the performance of FMT systems in doubly selective fading channels and is very suitable for broadband wireless transmission systems in high speed mobile environments. |
| Key words: broadband wireless transmission filtered multitone(FMT) continuous phase modulation(CPM) hybrid modulation doubly selective fading |
