Layered Orthogonal Frequency Division Multiplexing With Index Modulation
Layered Orthogonal Frequency Division Multiplexing With Index Modulation
复制标题
带索引调制的分层正交频分复用
DOI：
10.1109/jsyst.2019.2918068
复制
发表时间：
2019
影响因子：
4.4
通讯作者：
Hai Han
中科院分区：
文献类型：
--
作者：
Li Jun;Dang Shuping;Wen Miaowen;Jiang Xue-Qin;Peng Yuyang;Hai Han
为了提高OFDM-IM系统的频谱效率，本文提出了一种新的分层正交频分复用索引调制（L-OFDM-IM）方案。在L-OFDM-IM中，首先将所有子载波分成多层，每一层确定有源子载波及其调制符号。索引调制比特是在各层有源子载波的索引上进行的，这些索引与不同的信号星座重叠且可区分，因此索引调制比特的数量比传统的OFDM-IM要多。提出了一种低复杂度的检测方法，以减轻最优最大似然检测在接收端的高负担。推导了L-OFDM-IM误码率、可实现率和分集阶数的封闭上界来表征其性能。为了提高L-OFDM-IM的分集性能，我们进一步提出了坐标交错L-OFDM-IM (CI-L-OFDM-IM)，它在两个不同的子信道上交错调制符号的实部和虚部。计算机仿真验证了理论分析，结果表明L-OFDM-IM方案优于传统的OFDM-IM方案。此外，还证实了CI-L-OFDM-IM比L-OFDM-IM获得了额外的分集阶数。
In this paper, we propose a novel scheme termed layered orthogonal frequency division multiplexing with index modulation (L-OFDM-IM) to increase the spectral efficiency (SE) of OFDM-IM systems. In L-OFDM-IM, all subcarriers are first divided into multiple layers, each determining the active subcarriers and their modulated symbols. The index modulation (IM) bits are carried on the indices of the active subcarriers of all layers, which are overlapped and distinguishable with different signal constellations so that the number of the IM bits is larger than that in traditional OFDM-IM. A low-complexity detection is proposed to alleviate the high burden of the optimal maximum-likelihood detection at the receiver side. A closed-form upper bound on the bit error rate, the achievable rate, and diversity order are derived to characterize the performance of L-OFDM-IM. To enhance the diversity performance of L-OFDM-IM, we further propose coordinate interleaving L-OFDM-IM (CI-L-OFDM-IM), which interleaves the real and imaginary parts of the modulated symbols over two different subchannels. Computer simulations verify the theoretical analysis, and results show that L-OFDM-IM outperforms the conventional OFDM-IM scheme. Moreover, it is also confirmed that CI-L-OFDM-IM obtains an additional diversity order in comparison with L-OFDM-IM.