Time domain combined estimate method for time coarse synchronization and frequency precise synchronization

Abstract

The invention discloses a time domain combined estimate method for time coarse synchronization and frequency precise synchronization in the orthogonal frequency division multiplexing (OFDM) system, which comprises the steps of: concurrently performing autocorrelation operation of small points length and autocorrelation operation of large points length on the base-band data sequence of a receiving end, concurrently determining the time coarse synchronization position through small points autocorrelation peak value and large points autocorrelation peak value at real time, and at the confirmation point of the time coarse synchronization position, determining the frequency detection result according to small points autocorrelation peak value and large points autocorrelation peak value. The invention improves the detection precision, solves the problem that the traditional time domain synchronization information can not detect the integral-multiple frequency offset so as to influence the precision of the subsequent time fine synchronization and the inaccurate integral-multiple frequency offset estimate and the symbol fine synchronization of the time frequency combined estimate method influence mutually, and solves the problem of long time-frequency synchronization time-delay and high operation cost.

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 joint estimation suitable for time coarse synchronization and frequency fine synchronization of a broadband data packet burst transmission Orthogonal Frequency Division Multiplexing (OFDM) system 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, wireless local area network standards WiFi (802.11a / g / n), WiMax (802.16d / e), LTE downlink, digital broadcasting systems DVB, CMMB, etc. all use OFDM technology. [0003] One of the main disadvantages of OFDM technology is that it is sensitive to time and frequency offsets. Time offsets will cause inter-symbol interfere...

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Problems solved by technology

[0008] In view of this, the main purpose of the present invention is to provide a time-domain joint estimation method with time-coarse synchronization and frequency-fine synchronization, so as to solve the problem of complex hardware design of the system measurement function due to the strict requirements of the timing measurement platform in the traditional time-frequency joint estimation method , Integer multiple frequency offset estimation and symbol fine synchronization are inaccurate and affect each other. Time-frequency synchronization estimates the fractional multiple frequency offset and integer multiple frequency offset respectively. Contradictions that lead to increased latency

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