A short feasibility study of a cognitive TV black space system
A short feasibility study of a cognitive TV black space system
复制标题
认知电视黑色空间系统的简短可行性研究
DOI：
10.1109/pimrc.2011.6140016
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
J. Sachs
中科院分区：
文献类型：
--
作者：
Y. Selén;R. Baldemair;J. Sachs
本文评估了在数字电视（DTV）系统上叠加二次系统的可行性。我们将这种类型的方法表示为TV黑色空间（与TV白色空间形成对比）。在这种类型的操作中，次发射机在与DTV系统相同的频谱资源上进行发射。特别是，我们考虑的情况下，二次发射机与DTV发射机并置，并使用相同的天线。用于辅助信号的总发射功率的部分被设置得足够低，使得DTV接收器总是能够解码DTV信号。黑空间接收机解码TV信号分量，并从总接收信号中消除它，这导致残差中的辅助信号的改善的SINR。数值评估表明，这种类型的覆盖在DTV频谱是可行的，只有当二次系统是满意的相对较低的SINR值约5至10分贝。在DTV信号消除之后确定辅信号SINR时的关键参数是主系统的SINR要求：DVB-T系统通常要求高于20 dB的SINR值，然后覆盖变得不太可行，因为留给辅信号的功率分数变得非常低。此外，发射机处的TX EVM噪声的实际水平（大约6%至8%）导致即使在接收机侧的DTV信号消除之后，次级信号的可实现的SINR值也较低。
This paper evaluates the feasibility of overlaying a secondary system on a digital TV (DTV) system. We denote this type of approach TV black space (in contrast to TV white space). In this type of operation the secondary transmitter transmits on the same spectrum resources as the DTV system. Particularly, we consider the case where the secondary transmitter is collocated with the DTV transmitter and uses the same antennas. The fraction of the total transmitted power that is used for the secondary signal is set low enough so that the DTV receivers are always able to decode the DTV signals. The black space receivers decode the TV signal component and cancel it from the total received signal which results in an improved SINR of the secondary signal in the residual. Numerical evaluations show that this type of overlay in the DTV spectrum is feasible only when the secondary system is satisfied with relatively low SINR values of around 5 to 10 dB. A critical parameter when determining the secondary signal SINR after DTV signal cancellation is the SINR requirements by the primary system: DVB-T systems typically require SINR values above 20 dB and then overlay becomes less feasible since the fraction of power left for the secondary signal becomes very low. Additionally, realistic levels of TX EVM noise (around 6% to 8%) at the transmitter causes low achievable SINR values for the secondary signal even after DTV signal cancellation at the receiver side.