接着，本论文对OFDM和多载波cdma的系统结构进行了讨论，对多载波cdma系统中的导频信道估计技术进行了深入研究。
Next, the system structure of OFDM and multi-carrier system are discussed, followed by the pilot based channel estimation for the multi-carrier CDMA systems.
至少一个导频信道输出提供确定估计分组差错率的基础。
At least one pilot channel output provides a basis to determine an estimated packet error rate.
提出了一种面向直接序列扩频（DS-CDMA）通信系统的基于导频信号的自适应信道估计方法。
The estimation scheme for DS-CDMA systems includes a computationally efficient and easily implemented pilot filter on CDMA forward channel.
这种方法可以更好地跟踪信道变化，显著地消除接收到的导频信号中的加性噪声，提高信道估计精度。
Such method could better track channel change and eliminate the noise remarkably in the received pilot signal, and the precision of channel estimation had been improved.
由于公共导频信道无功率控制，有可能在接收端接收到的公共导频信号的功率很低，使得信道估计的误差变大。
Because there is no power control in CPICH, the received common pilot signal power is possibly very low if the mobile is far from the base station, and this time the channel estimates is inaccurate.
提出了一种基于导频信号和最大似然信道估计算法的离散小波包调制(DWPM)系统。
Discrete Wavelet Packet Modulation (DWPM) System based on ML (Maximum Likelihood) algorithm and Optimum Pilot Symbol Assisted Modulation (OPSAM) is studied for Rayleigh Fading Channels.
利用有限的导频信号进行信道延迟估计从而获得准确的符号同步。
Channel delay estimation via pilot sub-carriers is used to provide accurate frame synchronization in multipath channels.
首先介绍了基于导频信号的辅助信道估计过程，并据此给出了信道模型。
The auxiliary channel estimating process based on pilot signal is introduced, and a model for the auxiliary channel is presented according to the process.
与数据符号中的导频信号联合进行估计，从而能跟踪信道的变化，进一步提高信道估计的性能。
It carries on the estimation jointly with the pilot signal of the data symbols, so that it can track the changes of the channel to further enhances the channel estimation performance.
与数据符号中的导频信号联合进行估计，从而能跟踪信道的变化，进一步提高信道估计的性能。
It carries on the estimation jointly with the pilot signal of the data symbols, so that it can track the changes of the channel to further enhances the channel estimation performance.
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