Time frequency synchronization method of short distance wireless network

A short-range wireless, time-frequency synchronization technology, applied in the direction of shaping network, multi-frequency code system, electrical components, etc. in transmitter/receiver, can solve problems such as large amount of calculation

Inactive Publication Date: 2009-07-29
BEIJING TRANSPACIFIC IP TECH DEV
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Problems solved by technology

However, because the phase estimation interval is -π~π, this method can only estimate -1 / 2T s ~1 / 2T s frequency offset between, here T s is the period of the spreading sequence
For frequency offsets beyond this range, the traditional GPS uses a time-frequency two-dimensional search method to perform sliding correlation in the time domain and frequency domain, and estimate the synchronization point of time and frequency according to the peak value of all correlation values. This method is relatively accurate to achieve time-frequency synchronization, but the amount of calculation is too large

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  • Time frequency synchronization method of short distance wireless network
  • Time frequency synchronization method of short distance wireless network
  • Time frequency synchronization method of short distance wireless network

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[0030] In the short-range wireless network that the present invention proposes, the time-frequency synchronization method of two correlations, its flow chart is as follows figure 1As shown, first receive the radio frequency signal sent by the transmitter in the short-range wireless network, perform down-conversion to obtain the baseband received signal, and use T for the baseband received signal C Sampling for the time interval, obtain baseband 2 times sampling received signal; Then start from any sampling point of above-mentioned received signal, read the received signal of three chip cycle lengths, this received signal sequence is denoted as r=[r 1 , r 2 ,...,r N , r N+1 , r N+2 ,...,r 2N ,,r 2N+1 r 2N+2 ,...,r 3N ], where N represents the number of sampling signals in one symbol cycle time; the first 2N sampling signals in the above-mentioned received signals are sequentially conjugated to obtain a conjugate sampling signal sequence r ...

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Abstract

The invention relates to a time-frequency synchronizing method with twice correlation in a short-distance wireless network and belongs to the technical field of wireless communication. Firstly, cross-correlation of a received digital signal is implemented by utilizing the periodic repeating characteristic and the well correlation characteristic of training sequences, thus obtaining a group of new receiving related value sequences; the same cross-correlation operation of local spread spectrum modulating sequences is implemented, thus obtaining a group of new local related value sequences; sliding correlation of the receiving related value sequences and the local related value sequences is implemented, thus obtaining a group of sliding related value sequences; and an estimated value of frequency deviation and a synchronizing position of time are determined according to the maximum value of all related values, thus realizing combined time-frequency synchronization. The time-frequency synchronizing method of the invention reduces the calculation amount of time-frequency synchronization and estimation, improves the performance of time synchronization and frequency deviation estimation under the influence of frequency deviation, and leads a receiver to have lower energy consumption and better receiving performance in the situation of larger frequency deviation.

Description

technical field [0001] The invention relates to a time-frequency synchronization method in a short-range wireless network, in particular to a time synchronization and frequency synchronization method in a short-range wireless network, and belongs to the technical field of wireless communication. Background technique [0002] Modern wireless network communication adopts the packet transmission mechanism, and the transceivers communicate by transmitting data packets. Time and frequency synchronization must be performed between transceivers before each data transmission begins to ensure that the receiver can accurately resume sending information. [0003] In a spread spectrum based system, time synchronization should find the boundaries of the spread spectrum sequence and the best sampling moment of the pulse corresponding to each element in the sequence. The frequency synchronization is to keep the carrier frequencies of the receiving end and the transmitting end consistent, ...

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Application Information

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IPC IPC(8): H04L27/26H04L25/03H04B1/707
Inventor 张良赵振丰
Owner BEIJING TRANSPACIFIC IP TECH DEV
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