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.