认知无线电超宽带多址与抗干扰技术研究

项目名称： 认知无线电超宽带多址与抗干扰技术研究

项目编号： No.60872002

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 能源与动力工程

项目作者： 包志华

作者单位： 南通大学

项目金额： 28万元

中文摘要： 项目从融合的角度研究了基于认知无线电(CR)的多带正交频分复用超宽带（MB-OFDM-UWB）系统多用户频谱资源分配与抗干扰技术。通过准确的频谱感知、合理的资源分配，使得UWB系统能实时自适应周围频谱环境，提高系统容量，最大限度地消除或抑制干扰。研究了基于干扰特征的交织与编码联合抗干扰算法,设计了多址与抗干扰一体化的系统模型。在此基础上，研究了单节点频谱检测与多节点频谱协作检测算法，推导了最佳判决门限和无线认知中继协作感知的频谱检测性能，提出了线性合并算法以及基于循环平稳特征的能量检测算法，提高了在低信噪比环境下的频谱检测性能，克服了噪声波动对频谱检测性能的影响，对不同调制制度的主信号感知具有稳健性。进一步，根据无线认知中继网络上、下行链路子载波的信道特性，研究了认知网络的频谱资源分配，提出上、下行链路子载波联合优化的分配算法，以子信道增益差值因子的大小分配下行链路子载波，以源节点和中继节点功率最小化配对上行链路子载波，以用户的实时需求分配子载波的比特和功率，有效降低了系统发射功率，提高了系统吞吐量。最后，建立了基于CR的MB-OFDM-UWB实验平台，验证了理论结果。

中文关键词： 认知无线电；超宽带；多址；抗干扰

英文摘要： This program focused on the spectrum resource allocation and anti-interference of multi-users in multi-band OFDM-UWB system (MB-OFDM-UWB), which is based on cognitive radios. It makes MB-OFDM-UWB system accesses the surrounding spectrum adaptively and actually-time, increases the capacity, and eliminates or restrains the interference as complete as possible by accurate spectrum sensing and reasonable resource allocating. The anti-interference algorithm that combines interleaving with coding was proposed, the UWB system that integrates multi-access and anti-interference was designed. Then, the spectrum sensing techniques based on single node and multi nodes were studied. The optimized detecting threshold and the closed-form expressions of detection probability in relay cooperative spectrum sensing were derived, the linear combination algorithm as well as the cyclostationary spectrum sensing algorithm were proposed. It improves the spectrum sensing performance in low signal-to-noise ratio, removes the effect of noise uncertainty, and has the robustness to different modulated primary signal. Then, the spectrum resource allocation algorithm was proposed according to the subcarrier characteristics of the uplink and downlink in cognitive relay networks. The algorithm allocates the subcarriers in downlink by the difference of subchannel gains, assigns the subcarriers in uplink by minimizing the powers of source nodes and relay node, and distributes the bits and powers of all subcarriers. It could decrease the power transmitted and increase the throughput of the system. Finally, the cognitive experimental development platform of MB-OFDM-UWB was established and the theoretical results were validated.

英文关键词： cognitive radios; ultra wideband; multi-access; anti-interference