首先是“载波感测”。以太网站先检查“以太”是否空载，如果检测到信号了就排队等候自己的发送机会。

First of all, Ethernet stations check to see if the ether is idle (carrier sense) and wait if they sense a signal.

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理论分析和仿真实验证明，在负信噪比条件下该方法可有效提高对DS-SS信号载波的检测能力。

Then we detect and estimate the carrier frequency of negative SNR DS-SS Signal have done. Theoretic analysis and simulation prove the validity of the arithmetic.

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探讨如何进行射频载波抵消以及检测放大器互调失真信号。

How to cancel carrier and detect the intermodulation distortion signal of power amplifier will be discussed.

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