Channel estimation in a pilot assisted OFDM system

摘要

An accurate channel frequency response is obtained by processing an extracted number of pilot tones provided at different locations within a received OFDM symbol. This includes filtering the extracted pilot tones with a first window function, converting the thus filtered pilot tones to a first channel impulse response signal that may include a main tap and a plurality of adjacent taps, removing taps whose absolute values or energy levels are below a predetermined level, processing the remaining taps having sufficient absolute values or energy levels into a second channel impulse response signal that is significantly free of noises, converting the second channel impulse response signal to a frequency-domain signal, and filtering the frequency-domain signal with a second window function having an inverse characteristic of that of the first window function to obtain an accurate channel frequency response.

主权项

1. A computer-implemented method of estimating a channel in a pilot assisted OFDM system, the computer-implemented method comprising:
receiving an RF signal; down-converting the RF signal to a baseband signal; converting the baseband signal to a digital baseband signal; converting the digital baseband signal to a frequency-domain signal, the frequency-domain signal including an OFDM symbol having a plurality of data carriers and a plurality of pilot tones; extracting at least a subset of the plurality of pilot tones; filtering the extracted pilot tones; obtaining a channel impulse response from the filtered pilot tones, the channel impulse response comprising a plurality of taps; selecting a number of taps from the plurality of taps; converting the selected number of taps into a channel frequency response; and filtering the channel frequency response.