OFDM automatic closed-loop transmitting scattered pilot insertion control method

Abstract

The invention relates to a method for utilizing a bit error ratio (BER) estimated by a receiving end of an OFDM system to dynamically and automatically closed-loop regulating an inserted interval of dispersed pilot frequency of a sending end. The method of the invention comprises the steps that: an increased command is given to inform the sending end to increase the amount of the inserted pilot frequency when the BER of the received data exceeds a constant value; a reduced command is given to inform the sending end to reduce the amount of the inserted pilot frequency when the BER of the received data is lower than the constant value; the frame format of each sent OFDM frame is indicated at the sending end, and the information of the frame format is inserted behind the first pilot frequency unit. By adopting the method of the invention, the amount of the inserted pilot frequency can be timely and dynamically regulated according to the condition of a signal path, therefore, the requirements of the system on the BER value are met, and the frequency spectrum efficiency is improved to the greatest extent.

Description

technical field [0001] The invention relates to the field of mobile communication, in particular to a method for automatic closed-loop transmission scattered pilot insertion control in an Orthogonal Frequency Division Multiplexing (OFDM) system of broadband mobile wireless communication. Background technique [0002] In recent years, in the new generation of broadband mobile wireless communication systems, Orthogonal Frequency Division Multiplexing (OFDM) technology has replaced single-carrier spread spectrum technology, such as CDMA, and has become the mainstream basic transmission technology. The early adoption of OFDM technology includes digital broadcasting DAB and digital TV DVB. Subsequently, broadband wireless access system standards IEEE 802.11g / a / n, 802.16d / e and 802.20 under formulation are also based on OFDM / OFDMA technology. In addition, the 3GPP LTE long-term evolution technology and 3GPP2AIE air interface evolution technology that are currently being standardi...

AI Technical Summary

Problems solved by technology

But there is no measurement method for the maximum delay spread and relative Doppler frequency shift. In fact, the maximum delay spread and relative Doppler frequency shift engineering measurement is difficult

making this method difficult to implement in engineering

[0012] Moreover, in the existing adaptive technology, only how to use the channel information estimated by the receiving end to adjust the power, modulation and other parameters of the transmitting end, or only choose an adaptive channel estimation scheme at the receiving end, and use the estimated channel information of the receiving end There is no practical method to adjust the pilot insertion interval of the sending end due to the difficulty of coherent time and coherent bandwidth estimation.

Images