LTE网络中干扰抑制技术研究

发布时间：2018-06-09 03:39

本文选题：LTE + 同频干扰　；参考：《重庆邮电大学》2014年硕士论文

【摘要】：以OFDM和MIMO为核心技术的LTE网络采用同频组网的方式，为移动通信系统提供了更高的数据传输速率、频谱利用率和网络覆盖能力。考虑到实际无线信道传输时延的影响，，使得LTE网络采用同频组网的干扰控制并不理想，同时多小区复用相同频率资源使得小区边缘用户的同频干扰问题也较为突出，这些都会导致传输可靠性、系统容量和能量效率等性能下降。为此，本文通过引入传输时延和分解信道矩阵的方法，研究LTE网络中的干扰抑制问题。具体研究内容如下：针对OFDMA多址接入信道传输时延的不确定性，从信号域时延出发分析推导了系统中干扰的闭合表达式，验证了不同相对时延方差下同频干扰对系统性能的影响。考虑到干扰的异步非相关性以及传统干扰抑制合并算法的局限性，利用卷积码时延小、高编码增益的优点，采用编码干扰抑制合并算法抑制干扰。仿真结果表明，时延导致的同频干扰在很大程度上降低了系统的误比特率性能，而编码干扰抑制合并算法克服了干扰抑制合并的局限，使得系统误比特率性能得到提升。针对LTE网络多小区多用户下行链路同频干扰问题，给出一种结合三角分解和信漏噪比的干扰抑制算法。该算法通过对联合信道进行三角分解先将小区间干扰消除了一半，得到等效的系统模型，然后基于此模型根据不同小区的干扰情况，利用信漏噪比和干扰抑制矩阵消除余下的干扰。理论分析表明，三角分解和信漏噪比联合算法使得接收端不需要再增加用于抑制小区间干扰的矩阵及相应矩阵运算，简化了接收端处理，降低了计算复杂度。计算机仿真表明，该算法能够有效地改善系统容量和能量效率等性能。
[Abstract]:The LTE network with OFDM and MIMO as the core technology uses the same frequency network to provide higher data transmission rate spectrum efficiency and network coverage for mobile communication systems. Considering the influence of real wireless channel transmission delay, the interference control of LTE network using the same frequency network is not ideal. At the same time, the multi-cell multiplexing the same frequency resources makes the problem of co-frequency interference of the edge users of the cell more prominent. These will lead to transmission reliability, system capacity and energy efficiency and other performance degradation. In this paper, the interference suppression problem in LTE networks is studied by introducing transmission delay and decomposing channel matrix. The specific research contents are as follows: aiming at the uncertainty of transmission delay in OFDMA multiple access channel, the closed expression of interference in the system is derived from the signal domain delay. The effect of the same frequency interference on the performance of the system is verified under different relative delay variances. Considering the asynchronous non-correlation of interference and the limitation of traditional interference suppression and merging algorithm, this paper uses the advantages of small time delay and high coding gain of convolutional code to suppress interference by coding interference suppression combination algorithm. The simulation results show that the time-delay co-frequency interference greatly reduces the bit error rate performance of the system, and the coding interference suppression combination algorithm overcomes the limitation of interference suppression combination. The BER performance of the system is improved. Aiming at the co-frequency interference problem of multi-cell and multi-user downlink in LTE network, an interference suppression algorithm combining triangulation decomposition and signal-to-noise ratio is proposed. By triangulation decomposition of the joint channel, the inter-cell interference is eliminated in half, and the equivalent system model is obtained. Based on this model, the interference of different cells is analyzed. The remaining interference is eliminated by using signal-to-noise ratio and interference suppression matrix. Theoretical analysis shows that the algorithm of triangulation decomposition and signal-to-noise ratio makes it unnecessary for the receiver to increase the matrix and matrix operation to suppress inter-cell interference, which simplifies the processing of the receiver and reduces the computational complexity. Computer simulation shows that the algorithm can effectively improve the system capacity and energy efficiency.
【学位授予单位】：重庆邮电大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

【参考文献】