应用于极坐标发射机的宽带调相技术研究

发布时间：2018-03-07 00:20

本文选题：极坐标发射机　切入点：宽带相调制　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：极坐标发射机是一种理论上可以同时满足高效率和高线性度指标的发射机结构。而由于现代通信中基带数据传输的速率越来越高,传统应用于极坐标发射机中的基于锁相环的相位调制结构已经无法满足系统对于带宽的要求,因此新型的宽带相位调制结构是本文研究的重点。本文在基于对数字时钟信号的新型定义下,研究了一种宽带相位调制系统,即基于小数分频数字分频器的频率合成器。本文的主要工作和创新之处如下文所示：1.定义了新型的数字时钟信号。通用的数字时钟信号是单一周期的无限次重复,而在本文定义的数字时钟信号是由多个周期不同的基本信号在长时间的平均得到的平均周期。采用如上定义的数字时钟信号比起通用时钟信号来说,其硬件电路实现将会简单,对于大规模集成电路会是一个好处。2.研究了基于小数分频数字分频器的频率合成器。这种频率合成器的输出时钟信号是定义了的新型数字时钟信号,即其输出频率是若干个基本频率的综合而成,而不是传统意义中的单一频率；除此之外,其输出信号是方波形式,有益于数字电路的集成。3.本文研究的基于小数分频数字分频器的频率合成器的宽带相位调制系统是一个开环的相位调制系统。因为该相位调制系统是开环系统,所以基带数据的速率不会受到像锁相环式的相位调制系统中的闭环带宽影响；因此对于宽带相位信号来说,该方案是可行的。4.研究了宽带相位调制系统中的重要模块,即无杂散量化模块。该模块的设计采用了统计的思想,将确定性的杂散信号转化为不确定的杂散信号,使其功率谱的幅值小于输出信号的噪底,在这种情况下可以保证输出信号的功率谱输出无杂散。除此之外,在对连续量化器的设计之初就考虑了非线性电路对于输出信号频谱的影响,因此连续量化器输出的量化噪声的多次方功率谱均无杂散信号。硬件测试结果表明在该系统的参考输入时钟信号的频率是1GHz时,基带相位信号的传输速率可以达到20Mbps,而其EVM可以保持在4.54%。而其在不同参考时钟信号的频率下其EVM是不同的结果,理论上来讲,参考输入时钟信号的频率越高,EVM的效果可以更好。因此基于小数分频数字分频器的频率合成器可以作为宽带相位调制器使用。
[Abstract]:Polar coordinate transmitter is a transmitter structure which can satisfy both high efficiency and high linearity in theory. However, because of the increasing rate of baseband data transmission in modern communication, The traditional phase-locked loop (PLL) based phase modulation structure used in polar transmitters can no longer meet the bandwidth requirements of the system. Therefore, a novel wideband phase modulation structure is the focus of this paper. Based on the new definition of digital clock signal, a wideband phase modulation system is studied in this paper. The main work and innovation of this paper are as follows: 1. A new digital clock signal is defined. The universal digital clock signal is an infinite repetition of a single period. The digital clock signal defined in this paper is the average period obtained from the average period of several different basic signals over a long period of time. Using the digital clock signal defined above, the hardware implementation of the digital clock signal will be simpler than that of the universal clock signal. The frequency synthesizer based on fractional frequency divider is studied. The output clock signal of this frequency synthesizer is a new digital clock signal defined. That is, its output frequency is a combination of several basic frequencies, rather than a single frequency in the traditional sense; in addition, its output signal is in the form of square waves. The broadband phase modulation system based on frequency synthesizer based on fractional frequency divider is an open-loop phase modulation system, because the phase modulation system is an open-loop system. Therefore, the rate of baseband data will not be affected by the closed-loop bandwidth in phase-locked loop (PLL) phase modulation system; therefore, this scheme is feasible for wideband phase signals. 4. The important modules in wideband phase modulation system are studied. The design of the module adopts the idea of statistics, which converts deterministic stray signal into uncertain spurious signal, and makes the amplitude of power spectrum smaller than the noise bottom of output signal. In this case, the power spectrum output of the output signal can be guaranteed without stray. In addition, the influence of nonlinear circuit on the output signal spectrum is considered at the beginning of the design of the continuous quantizer. Therefore, there is no stray signal in multiple square power spectrum of quantization noise output by the continuous quantizer. The hardware test results show that when the frequency of the reference clock signal of the system is 1GHz, The transmission rate of the baseband phase signal can reach 20 Mbpss, and its EVM can be kept at 4.54.The EVM of the baseband phase signal is different at different frequency of the reference clock signal, theoretically speaking, The higher the frequency of the reference clock signal, the better the effect of EVM. Therefore, the frequency synthesizer based on the fractional digital frequency divider can be used as the wideband phase modulator.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN830

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