Method and system for jointly estimating frequency offset

Abstract

The invention provides a method and a system for jointly estimating frequency offset, in order to overcome the detect of an estimation error due to the fact that a range of frequency offset estimation by utilizing two rows of reference signals on a subframe of a PUSCH (Physical Uplink Shared Channel) in a high-speed mode is too small. The method comprises the steps that a frequency offset sign is estimated according to a Preamble detection result in PRACH (Physical Random Access Channel) detection; a relevant estimated frequency offset value within plus-minus 1KHz is calculated according to the two rows of reference signals on the PUSCH; the estimated frequency offset value on the PUSCH is corrected according to the estimated frequency offset sign during Preamble detection; and a final frequency offset value is obtained.

Description

technical field [0001] The present invention relates to the field of wireless communication, and more specifically, the present invention is directed to a method and system for frequency offset estimation in the fourth generation mobile communication system (hereinafter referred to as 4G). Background technique [0002] In the 4G system, since the key technology used in the physical layer is OFDM (Orthogonal Frequency Division Multiplexing) technology, OFDM technology is easily affected by frequency offset, so it is necessary to accurately estimate the system frequency at the receiving end. frequency offset. [0003] In the uplink receiving system of the 4G system, two columns of reference signals on a subframe of the physical uplink shared channel (PUSCH) are generally used for frequency offset estimation by correlation. The two columns of reference signals on a subframe of the physical uplink shared channel (PUSCH) are as follows: figure 1 As shown, one slot in the figure ...

AI Technical Summary

Problems solved by technology

For the 4G system, the frequency offset mainly includes the frequency offset caused by the Doppler frequency shift and the frequency offset caused by the crystal oscillator deviation of the base station system and the terminal system itself. For the uplink receiving system, the maximum frequency offset will reach twice the maximum Doppler frequency. The maximum Doppler frequency shift is 583Hz, so the maximum frequency deviation in the uplink receiving system is 1166Hz, and the crystal oscillator of the base station system and the terminal system have not been considered here. The frequency deviation caused by the deviation of

Therefore, in a high-speed environment, using two columns of reference signals on a subframe of PUSCH for frequency offset estimation will cause estimation errors due to the actual frequency offset value being too large

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