一种线性化的全双工MIMO收发器设计  

Novel Design of Linear Full-duplex MIMO Radios

作　　者：张志亮[1,2] 沈莹[1] 邵士海[1] 潘文生[1] 唐友喜[1] 

机构地区：[1]电子科技大学通信抗干扰技术国家级重点实验室,成都611731 [2]四川大学锦城学院电子信息工程系,成都611731

出　　处：《电子与信息学报》2016年第9期2227-2232,共6页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61471108,61501093);国家科技重大专项(2014ZX03003001-002)

摘　　要：针对全双工MIMO收发器发射通道非线性以及接收通道存在强烈自干扰的问题,该文提出一种使发射通道线性化并通过射频多抽头重建与数字重建消除自干扰的具有较低硬件成本与软件复杂度的设计方案:(1)基于改进的串扰消除和数字预失真(CTC-DPD)算法并复用反馈通道进行去耦合和数字预失真使发射通道线性化、等增益;(2)在接收通道加入可调衰减器并用多维梯度下降法基于接收的残留自干扰功率最小原则调整抽头参数;(3)基于频域信道估计进行数字自干扰重建。实现的20 MHz带宽LTE全双工2′2 MIMO通信样机,发射通道经过线性化后带内更平坦,而带外噪声抑制了约30 d B。射频和数字消除一轮调整共耗时约0.17 ms,总消除能力约75 d B。16QAM映射时全双工双向数据速率总和220 Mbps,相对单向时的110 Mbps实现了频谱效率的翻倍。通信样机证明了该方案的可行性。Considering the issues of nonlinearity and self-interference in transmitting and receiving channels of a full-duplex MIMO radio respectively, a novel low hardware cost and low software complexity design scheme with transmitting channels linearization and self-interference cancellation by multi-tap RF cancellers and digital cancellers is proposed, where （1） An improved Cross-Talk Cancelling-Digital Pre-Distorter （CTC-DPD） algorithm and common feedback are used for decoupling and digital pre-distortion to make transmitting channels gain linearly and equally; （2） By introducing adjustable attenuators in receiving channels, multi-tap cancellers use received data along with minimum residual self-interference power criterion based multidimensional gradient descent method to search the multi-tap setting; （3） Digital self-interference is reconstructed for cancellation based on channel estimation in frequency domain. In the prototype of 20 MHz bandwidth LTE full-duplex 2 - 2 MIMO radio, transmitting channels have more flat in-band spectrum and 30 dB lower out-band noise after linearization. RF and digital self-interference cancellation need 0.17 ms for one turning and provide about 75 dB cancellation together. When two nodes with 16QAM mapping work at full-duplex mode, they achieve a sum of 220 Mbps bit rate, which double the bit rate of 110 Mbps at half-duplex mode and thus double the spectrum efficiency. The prototype demonstrates the feasibility of the proposed design.

关 键 词：无线通信 串扰 非线性 全双工 MIMO 

分 类 号：TN92[电子电信—通信与信息系统]