CAJ | 학술논문

本文充分考虑了认知超宽带系统频谱构形的物理层实现难度,进而选择伪混沌脉冲位置调制( Pseudo-Chaotic Pulse Position Modulation, PCPPM)作为超宽带系统调制方式。分析了PCPPM-UWB脉冲信号频谱特性,实验证明PCPPM-UWB脉冲信号的连续谱线部分具备类噪声特性可以与窄带系统共存,而离散谱线部分干扰强度大,无法与窄带系统共存。在此基础上提出了一种基于PCPPM的认知超宽带频谱构形方法,该方法通过改变PCPPM调制参数将离散谱线移出主用户频带范围,使主用户带宽内仅存在功率受限的连续谱部分,这样可以保证当主用户恢复传输时不会受到认知用户的强干扰,且认知用户也不会出现因切换频段而造成通信中断问题。
본문충분고필료인지초관대계통빈보구형적물리층실현난도,진이선택위혼돈맥충위치조제( Pseudo-Chaotic Pulse Position Modulation, PCPPM)작위초관대계통조제방식。분석료PCPPM-UWB맥충신호빈보특성,실험증명PCPPM-UWB맥충신호적련속보선부분구비류조성특성가이여착대계통공존,이리산보선부분간우강도대,무법여착대계통공존。재차기출상제출료일충기우PCPPM적인지초관대빈보구형방법,해방법통과개변PCPPM조제삼수장리산보선이출주용호빈대범위,사주용호대관내부존재공솔수한적련속보부분,저양가이보증당주용호회복전수시불회수도인지용호적강간우,차인지용호야불회출현인절환빈단이조성통신중단문제。
Taking full account of the physical-layer difficulty in CUWB spectrum configuration, PCPPM ( Pseudo Chaotic Pulse Position Modulation) is chosen as the modulation technology of UWB system. The spectrum characteristics of PCPPM-UWB signal are analyzed. Simulations verify that the successive spec-trum line of PCPPM-UWB pulse signal is noise-like, thus could coexist with narrow-band system while the the discrete spectrum could not, due to the intensive inteference. In light of this, a cognitive UWB spectrum condiguration method based on PCPPM is proposed. This method shifts the discrete spectrum line away from the the primary user frequency range via changing the modulation parameter,with only the power-confined smooth spectrum in the primary user frequency range. Therefore, the primary user is prevented from strong jamming from cognitive user when it restarts transmitting, and the cognitive user could avoid the communication interruption when switching the spectrum range.