A synchronization method in orthogonal frequency division multiplexing system

A technology of orthogonal frequency division and sub-synchronization, applied in transmission systems, synchronizing devices, digital transmission systems, etc., can solve the problems of not getting a closed-form solution of frequency offset and being sensitive to frequency offset.

Inactive Publication Date: 2007-11-28
ZTE CORP
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] Compared with single-carrier systems, OFDM has the above advantages, but also has its own disadvantages: it is very sensitive to frequency offset
This method avoids the use of too many symbols for synchronization and i

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  • A synchronization method in orthogonal frequency division multiplexing system
  • A synchronization method in orthogonal frequency division multiplexing system
  • A synchronization method in orthogonal frequency division multiplexing system

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Embodiment Construction

[0039] Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0040] Referring to Fig. 1, it is a schematic flow diagram of a method for realizing synchronization in the OFDM wireless system described in the embodiment of the present invention, and the specific process is as follows:

[0041] Step 110: Construct a preamble / synchronization sequence at the sending end and frame it for sending.

[0042] The sending end constructs a preamble / synchronization sequence when framing, and its preferred scheme includes a cyclic prefix and a PN sequence. The preamble sequence may include at least one preamble symbol, and its time domain characteristic is that the length is N I The PN sequence repeats I times, where I=N / N I, N is the number of subcarriers of OFDM. The OFDM data symbols to be sent are sent by the sending antenna after being framed.

[0043] Step 120: Perform primary time synchronization in combina...

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Abstract

The invention discloses a synchronous realizing method in the orthogonal frequency-division multiplying system, which comprises the following steps: constructing front/synchronous sequence at the transmitting end to frame and transmit; combining the CP information to do one-time synchronization; utilizing front symbol to estimate the integral times and decimal time-domain frequency deviation; compensating the frequency deviation; using front symbol to do secondary time synchronization; proceeding disposal after synchronizing. The invention improves the synchronous precision to modify the system property as well as the received signal-to-noise ratio, which reduces the calculating quantity without adding the burden of system.

Description

technical field [0001] The invention relates to an Orthogonal Frequency Division Multiplexing (OFDM) system, in particular to a method for realizing synchronization in an OFDM wireless receiving system, belonging to the field of wireless or wired communication. Background technique [0002] With the development of digital signal processing technology and high-speed devices, Orthogonal Frequency Division Multiplexing (OFDM) has been successfully applied in DVB, DSL and WLAN systems. OFDM divides the spectrum into several orthogonal sub-channels in the frequency domain, and the carriers of each sub-channel overlap each other, which improves the spectrum utilization. Since the bandwidth of each sub-channel is relatively narrow, the frequency-selective channel has flat fading for each sub-channel signal for the entire transmission bandwidth signal, and the equalization can be performed separately for each sub-carrier, which greatly simplifies the receiver structure. Because OFD...

Claims

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Application Information

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IPC IPC(8): H04L7/027
Inventor 刘巧艳余秋星王衍文李峰
Owner ZTE CORP
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