comb pilot ofdm system receiver

Abstract

The invention discloses a comb-type pilot OFDM (Orthogonal Frequency Division Multiplexing) system receiver, comprising a setting module used for presetting an iteration cycle index threshold and a cycle index counting initial value; a synchronous module which employs a short preamble to realize coarse synchronization, and a long preamble to realize fine synchronization and frequency offset estimation; an estimation module which employs extracted pilot frequency in each data symbol to estimate the coefficient of a base expansion model, and then calculates the channel estimation value of a time domain corresponding data symbol; an equalization module utilizing a received frequency domain data symbol and a channel estimation result to perform frequency domain equalization; a demodulating, de-interleaving and channel decoding channel used for demodulating, de-interleaving and decoding equalized data; and a determination module used for determining whether an iteration cycle index reaches a preset iteration cycle index threshold; if not reaching the preset iteration cycle index threshold, performing a new cycle of channel estimation by utilizing decoded data, and if reaching the preset iteration cycle index threshold, further determining whether an iteration circulating forward-backward algorithm converges; if an iteration circulating forward-backward algorithm converges, completing a data receiving process, and otherwise, adjusting a synchronous position and performing channel estimation again. The Comb-type pilot OFDM system receiver is suitable for a high speed wireless communication system.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a comb pilot OFDM system receiver under high-speed mobile wireless channel. Background technique [0002] One of the core technologies of the intelligent transportation system is the short-range communication system applicable to the transportation field. In various transportation-specific short-range communication systems, the IEEE 802.11p standard is valued for its superior performance. [0003] The frame structure of the IEEE 802.11p protocol, the long and short preambles are the same as those of the IEEE 802.11a. figure 1 Schematic diagram of the frame structure adopted for IEEE802.11a / p, in which the first 10 symbols (symbol) are short preambles for coarse synchronization, while the last two symbols are long preambles for channel estimation and fine frequency offset estimation, GI2 is a guard time slot. The existing receiver structure of an IEEE 802.11a-based wireles...

AI Technical Summary

Problems solved by technology

However, in a high-speed mobile environment, the communication quality of the OFDM system is greatly reduced due to Doppler frequency shift and channel fast time-selective fading. The above receiver structure is not suitable for high-speed mobile dual-selection channels.

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