Pilot frequency design method and transmitting/receiving device for idem frequency interference suppression of OFDM system

Abstract

The invention provides a pilot design method and a trans-receiving device for preventing the co-frequency interference suppression of an OFDM (orthogonal frequency division multiplexing) system. The different subdistricts adopt pilot sequences generated by different basic orthogonal sequences, and different sectors respectively adopt the pilot sequences obtained by the same basic orthogonal sequence by different phase shifts in the same subdistrict; an emission end sequentially inserts the generated pilot sequences into pilot positions which are distributed bi-dimensionally and discretely with time frequency according to serial numbers of sub-carrier frequency domains to transmit; a receiving terminal firstly carries out relative treatment of the received frequency domain pilot signals and the local orthogonal pilot sequences and then eliminates the co-frequency interferences at time domains by making use of the shift orthogonal performance between the pilots after going through the IDFT (Inverse Discrete Fourier Transform). The device can effectively prevent the affects of pilots on the co-frequency interferences and can improve the channel estimation performance.

Description

technical field [0001] The invention relates to communication technology, in particular to orthogonal frequency division multiplexing technology. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) technology is a multi-carrier modulation technology. It was developed from Multi-Carrier Modulation (MCM). In an OFDM system, data is allocated to multiple sub-carriers with small bandwidth and orthogonal to be transmitted in parallel at the same time. The amount of data transmitted on each sub-carrier is very small, and different modulation methods can be used on each sub-carrier. By changing the bit rate on each subcarrier and increasing the symbol period on each subcarrier, the intersymbol interference caused by channel time dispersion can be effectively reduced. Since the bandwidth of each subcarrier is very small, much smaller than the coherent bandwidth of the channel, the frequency response on each subcarrier is flat, thus greatly reducing the ...

AI Technical Summary

Problems solved by technology

[0004] The pilot mode adopted by the IEEE802.16e standard is under the same-frequency networking and full-frequency multiplexing conditions. Since the pilot signals transmitted by the adjacent sector base stations completely collide on the subcarriers, the channel estimation performance of the terminal at the edge of the sector seriously deteriorated

[0005] Although the pilot scheme to be adopted in the 3GPP-LTE standard can effectively suppress the co-channel interference of adjacent sectors, it cannot make full use of the discrete pilots inserted in the time-frequency two-dimensional direction because the pilot sequences are arranged along the one-dimensional direction of the frequency. Frequency correlation to improve time-frequency two-dimensional interpolation channel estimation performance

Images