|
|
|
| A Joint Assisted Carrier Synchronization Algorithm with Code and Pilot Based on Low Rate LDPC Code |
| Yan Hui Tang Fa-jian Zhang Zhong-pei |
| National Key Laboratory of Science and Technology on Communications, University of Electronic Science and Technology of China, Chengdu 611731, China |
|
|
|
|
Abstract Considering that the code-aided and data-aided carrier recovery algorithms perform small synchronization range and big inaccuracy in low Signal to Noise Ratio (SNR) deep space communication systems, a joint assisted carrier synchronization algorithm with code and pilot is proposed. First a coarse synchronization algorithm with optimal pilot placement is constructed based on the sum of autocorrelation function of the pilots, whose frequency estimator can approximate Cramer-Rao Bound. The impact mechanism of pilot type on the trade-off between range and accuracy of estimation is analyzed. And then, a modified expectation maximization fine carrier synchronization is got with means of inserting pilot symbols and adding an integrator. Finally the simulations with the LDPC-Hadamard code with rate 1/12 verify that the new algorithm can increase synchronization range and improve accuracy, and achieve perfect synchronization with a certain amount of pilots at very low Signal to Noise Ratio.
|
|
Received: 06 April 2010
|
|
|
|
Corresponding Authors:
Yan Hui
E-mail: wateroflife@126.com
|
|
|
|
|
|
|
2011, Vol. 33 
