论文部分内容阅读
宽带次用户必须确保不会干扰带内已分配频谱的窄带主用户。目前已提出多种技术用于限定宽带次用户在特定的窄带内的功率泄漏。有源干扰抵消(AIC)能灵活地在数字域解决这个问题,因此无需增加额外的模拟硬件。其主要的挑战是,最终的零陷深度会受模拟器件的影响而严重恶化,比如功率放大器的非线性、相位噪声以及I/Q不平衡等。本文研究了I/Q不平衡对有源干扰抵消技术性能的影响。分析结果表明,发射器有3°相位不平衡和0.1dB增益不平衡时,零陷深度将从40dB(数字域)减少到28.7dB(无线电发射机的输出端)。为此本文介绍了一种补偿技术,并证明这种技术可以改善5~10dB的零陷深度,具体取决于I/Q不平衡的程度。
Broadband sub-users must ensure that they do not interfere with narrowband primary users in the band that have allocated spectrum. Various techniques have been proposed to limit the power leakage of broadband sub-users within a specific narrow band. Active interference cancellation (AIC) provides the flexibility to solve this problem in the digital domain without the need for additional analog hardware. The main challenge is that the final nulling depth can be severely degraded by analog components, such as the power amplifier nonlinearity, phase noise and I / Q imbalance. This paper studies the impact of I / Q imbalance on the performance of active interference cancellation techniques. The analysis shows that when the transmitter has a 3 ° phase imbalance and a 0.1 dB gain imbalance, the null depth will decrease from 40 dB (digital domain) to 28.7 dB (output of the radio transmitter). To this end, this paper presents a compensation technique that demonstrates that this technique can improve the null depth of 5 to 10 dB, depending on the degree of I / Q imbalance.