Orthogonal frequency division multiplexing received frame synchronizing method for co-training sequence mutual-correlation information

Abstract

The invention discloses an orthogonal frequency division multiplexing (OFDM) received frame synchronizing method for co-training sequence mutual-correlation information and is applicable to all OFDM systems adding training sequences in front of data frames. The OFDM received frame synchronizing method specifically includes 1), designing a frame structure of transmitting end; 2), performing mutual-correlation calculation and energy calculation synchronously by means of delay mutual-correlation algorithm at a receiving end, and obtaining regular measuring results; and 3) selecting energy threshold value and regular measuring threshold value of an energy window, and judging synchronous time. By accumulating a plurality of segment correlation values and uniformizing, operation load is reduced. The problems about peak platform and a plurality of high and side peak values are solved, and synchronization accuracy is increased. Channel influence is eliminated by receiving segmental mutual correlation of the sequence, and high frequency offset can be resisted. Dynamic range of receiving data is enlarged after uniformization, and selection of regular judgment time threshold value and synchronous detection can be simply and accurately realized. Meanwhile, adaptability is improved, frame synchronization in various channels can be completed accurately.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, in particular to an orthogonal frequency division multiplexing receiving frame synchronization method of joint training sequence mutual correlation information. Background technique [0002] Orthogonal frequency division multiplexing technology has the advantages of high spectrum utilization rate, fast data transmission rate and strong anti-multipath fading ability. However, it is also sensitive to timing offset and carrier frequency offset. In order to ensure the orthogonality of the subcarriers, the receiving end has very high requirements for synchronization. Inter-symbol interference (ISI) introduced by timing errors and inter-carrier interference (ICI) caused by frequency offset will lead to a sharp decline in OFDM system performance, so the OFDM frame synchronization detection problem is related to the correctness and reliability of data transmission. Most of the current fr...

AI Technical Summary

Problems solved by technology

Although the timing measurement of the H.Minn algorithm can produce a sharp peak at the correct time, it is also easy to appear multiple large peaks at the wrong time, which brings difficulties to the selection of the decision threshold, especially when the number of subcarriers is small. In a sudden system, the peak value at the wrong time often exceeds the peak value at the correct time, resulting in an estimation error

[0005] In addition, most synchronization algorithms are sensitive to frequency offset. When the frequency offset increases, the timing is often wrong, and when calculating the timing measurement, more data is used for correlation calculation and energy calculation, which increases the amount of calculation and affects the real-time performance of the system. sex

Images