Time-domain joint estimation method for synchronizing frames, frequencies and fine symbols for orthogonal frequency division multiplexing (OFDM)

Abstract

The invention discloses a joint estimation method for synchronizing frames, frequencies and fine symbols for orthogonal frequency division multiplexing (OFDM). The method comprises the following steps: carrying out autocorrelation operations of small point length and big point length on base band data sequences at the receiving terminal in parallel; jointly determining the frame synchronization position in real time and in parallel according to the small point autocorrelation peak and the big point autocorrelation peak; computing integer frequency offset coarse estimation value and decimal fraction frequency offset coarse estimation value according to the small point autocorrelation peak and the big point autocorrelation peak; estimating the final frequency offset detection value from the integer frequency offset coarse estimation value and the decimal fraction frequency offset coarse estimation value with a frequency offset dereferencing decision device; carrying out frequency offset correction on the base band data sequences according to the estimated final frequency offset detection value; and carrying out cross-correlation on the corrected base band data sequences and the local data sequences and determining the accurate fine symbol synchronization position through the cross-correlation peak. The contradiction of complex system measure function hardware design in the traditional time-domain joint estimation systems is solved by using the method.

Description

technical field [0001] The present invention relates to the technical field of synchronization in the communication field, and in particular to a time domain suitable for frame synchronization, frequency synchronization and symbol fine synchronization of a broadband data packet burst transmission Orthogonal Frequency Division Multiplexing (OFDM) system Joint Estimation Method. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) technology has been widely used in current broadband wireless communication systems and digital broadcasting communication systems because of its excellent anti-multipath capability and high spectrum utilization: for example, the wireless local area network standard WiFi (802.11a / g / n), WiMax (802.16d / e), LTE downlink, digital broadcasting system DVB, CMMB, etc. all adopt OFDM technology. One of the main disadvantages of OFDM technology is that it is sensitive to time offset and frequency offset. Time offset will cause int...

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Problems solved by technology

[0007] The main purpose of the present invention is to provide a time-domain joint estimation method suitable for frame synchronization, frequency synchronization, and symbol fine synchronization of broadband packet burst data OFDM systems, so as to solve the strict requirements of the timing measurement platform in the traditional time-frequency joint estimation method The contradiction caused by the complex hardware design of the system measurement function solves the contradiction between the inaccurate and mutual influence of the integer multiple frequency offset estimation and the symbol fine synchronization, and solves the time-frequency synchronization caused by separately estimating the fractional multiple frequency offset and the integer multiple frequency offset. The contradiction of large hardware operation overhead, and solve the contradiction of increased delay caused by the operation complexity of the time-frequency synchronization algorithm

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