Guiding plan based on time frequency synchronous training sequence

Abstract

This invention discloses a guiding project based on time and frequency's synchronized training sequence. It uses the good period correlated characteristic and constant amplitude of CAZAC sequence to serve the CAZAC sequence as the known measuring sequence, and cramps out a part of sequence from CAZAC sequence to serve as guiding signal. Amplifies properly the guiding signal's power, and inserts the digital signal into the relevant place of the guiding signal and sets to zero. The measuring sequence can either be used to synchronize the time and frequency, also can be used to the channel estimation. The invention can make more precise channel estimation, higher data demodulation performance to make the system tracing the fading of the channel more precisely and duly.

Description

technical field [0001] The invention belongs to the field of communication technology, in particular to a training sequence-based time and frequency synchronization method and a pilot symbol-assisted channel estimation method in the communication technology. Background technique [0002] OFDM has attracted more and more attention due to its high data transmission rate, strong anti-multipath interference ability, and high spectrum efficiency. It has been successfully used in wired and wireless communications. Such as: ADSL (Asymmetric Digital Subscriber Line), Wireless LAN, DAB (Digital Audio Broadcasting), DVB, EEE802.11a and HyperLAN / 2. In the IEEE802.16 currently being formulated, OFDM technology is also involved in a large number. OFDM, a new modulation technology, can also be used in a new generation of mobile communication systems. The use of OFDM technology will greatly improve the transmission data rate and spectral efficiency of the new generation of mobile commun...

AI Technical Summary

Problems solved by technology

[0009] The existing training sequence-based time and frequency synchronization methods have inherent limitations: when the relative energy of the training sequence (that is, the normalization of the total transmitted signal energy) is too large, it will generate strong interference to the data signal , so that the receiving end cannot correctly demodulate the expected data signal; when the energy of the training sequence is low, the transmitted data signal will strongly interfere with the training sequence, and when the receiving end performs synchronous operation, the correlation of the training sequence will be It will be damaged, and the time and frequency synchronization cannot be performed accurately

[0010] Similarly, the time and frequency synchronization method based on the training sequence also has an impact on the steering scheme: the training sequence will not only interfere with the transmitted data signal, but also interfere with the pilot signal inserted in the data signal, resulting in the loss of channel estimation at the receiving end. Inaccurate, resulting in performance degradation of the entire OFDM system

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