The predistortion , which aims at compensating for the nonlinear distortion caused by the power amplifier , has a good performance in eliminating the nonlinear distortion of am / am & am / pm , improving the aci and spectrum efficiency 预失真技术是针对射频功率放大器非线性而提出的一种补偿技术，可以有效消除由非线性造成的传输信号的幅度和相位失真，降低信号邻道干扰( aci ) ，提高频谱利用效率。
In order to suppress the mirror wave interference , this paper brings forward a predistortion correction method . utilizing the predistortion property of ddws , it directly modifies the original inputs with time domain information of the output distortion waveform , which 这种方法利用了ddws的预失真特性,在不添加硬件设备的前提下,直接利用输出的失真波形的时域信息对原输入波形进行预失真修正。
Simulation study shows 2 . 5db imd3 suppression can be improved compared with common polar lut predistorting system that has same 64 lut entries . besides the studying of indexing technique , the adaptive refresh algorithms of lut are studied and a new algorithm is obtained 仿真研究表明，在相同64位表项的极坐标预失真系统中，对比幅度索引技术该新型索引技术可以提高2 . 5db的imd3压缩性能，但不增加硬件实现成本。
The adaptive predistorter given can achieve the predistortion compensation based on piecewise estimating hpa nonlinear characteristic curve and training hpa estimator nonlinear parameters via performing inverse transform with curve fitting section by section 自适应预失真器是基于对大功率放大器的非线性特性进行分段估计，由曲线拟合逐段取逆变换来训练大功率放大器的预失真器的非线性参数，以达到预失真补偿的目的。
As far as linearity and efficiency are concerned , several techniques and theoretical analyses on linearity are extensively demonstrated . hybrid use of linear techniques and adaptation technologies in sdr are fully studied so that it can provides amplify with broadband , high efficiency and linearity . the paper presents a new scheme of an adaptive feedforward correction connected with a predistorter to amplify in sdr 在高效线性放大方面，广泛讨论了射频功放的几种线性化技术和非线性理论分析基础，深入研究了在软件无线电中组合使用线性化技术和自适应技术以保证宽带、高效率的线性放大，创新地提出了基于软件无线电宽带线性射频放大的预失真和自适应前馈线性技术结合的方案。
The basic technologic scheme on microwave transmission , currently maturate and advanced microwave transfer technology and equipment , efficiency slot gap antenna , character quality filter , mixer , exact crystalloid concussion apparatus , power backspacing technology , pre - distortion adjustment . furthermore , the technologic schemes practicing using multilevel microwave transfer technology in some areas such as lengshuijiang is introduced in the paper 采用了当前比较成熟、先进的微波传输技术和设备,如高效的缝隙天线、高品质滤波器、混合器、高精密的晶体震荡器、功率回退技术、预失真校正技术,结合工程实际,设计了湖南电广网络33家合资公司的mmds无线微波数字电视覆盖的基本技术方案,和个别地区(冷水江市数字微波工程)的多级微波传输的具体技术方案。
The rationale of the ofdm and the nonlinear effect of the power amplifier on the ofdm signals are presented in this paper , the principle of the adaptive digital predistortion is also introduced . on the basis of the rascal algorithm , this paper puts forward an improved algorithm that converges fast with low computing load and the related simulation . analysis on the quantity of the predistortion in the ofdm is also given 本文首先介绍了ofdm的基本原理以及功率放大器非线性对ofdm信号的影响；然后阐述了自适应数字预失真技术的基本原理，对其中使用的算法进行了分析和改进，使其在大幅节省资源的同时提高了收敛速度，并给出了相应的仿真结果；最后给出ofdm系统中关于预失真器设计的量化分析，并指出了今后线性化技术的发展趋势。
Before more advanced lithography tool is produced , in order to use current tools to manufacture vdsm ic , reticle correction methods such as perturbing the shape ( via optical proximity correction ( opc ) ) or the phase ( via phase - shifting masks ( psm ) ) of transmitting aperture in the reticle are proposed by the industry 在波长更小的光刻系统出现前，为了能利用现有设备解决集成电路的可制造性问题，工业界提出了对掩模作预失真(光学邻近校正)和在掩模上加相位转移模(移相掩模)等的掩模校正方法。
The principle of power amplifier is introduced at first in this paper , especially its nonlinearity characteristic under the condition of large signal . subsequently linearization technology such as power - retreat , negative feedback , pre - distortion and feed - forward are discussed . and then broadband matching technology is introduced . at last , the scheme of subject , the functional realization of each module , some questions which must be pay much attention in the system design , and the ultimate testing result of this subject is represented and analyzed in detail 本文首先介绍了线性功率放大器工作原理，尤其是在大信号条件下，它的非线性特征，这是设计线性功放必备的基础；接着介绍了当今一些前沿的功放线性化方法，例如预失真和前馈技术；然后详细讨论了宽带匹配技术，特别是传输线变压器的原理和应用，这是因为传输线变压器在本课题中扮演了重要的角色；最后具体叙述了本课题采用的方案、各个模块的功能的实现、实际设计应注意的问题。
In this paper , a new advanced general wide - band signal generator module is developed , which uses high speed fpga as its control - unit . the module can work in any system with different bandwidth and can generate any kind of lfm signal , whose bandwidth is less than 200mhz , and time - width is less than 870us 该模块具有标准的输入输出接口,不同波段、不同带宽的雷达系统均能直接使用,可以产生带宽200mhz以内、脉冲宽度870us以内的线性调频信号,具有预失真功能,能补偿系统的特性特性失真,还可直接通过4倍频或8倍频实现带宽的扩展。
