Method and apparatus for channel estimation
First Claim
1. A method for improving channel estimation over a fast fading channel, comprising the steps of:
- generating a coded OFDM signal including a main signal portion coded using a first signal code and a pilot signal portion coded using a second signal code;
transmitting the coded OFDM signal over a fading channel;
detecting a received main signal within the coded OFDM signal;
detecting a received pilot signal within the coded OFDM signal;
estimating a frequency response of the fading channel carrying the transmitted coded OFDM signal from the detected pilot signal; and
determining an estimated received signal from the detected received main signal and the estimated frequency response of the fading channel.
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Abstract
A method for channel response estimation over a fast fading channel and signal estimation using a coded pilot is disclosed. A coded orthogonal frequency division modulated (OFDM) signal is generated including a main signal portion and a coded pilot signal portion. The coded OFDM signal is transmitted over a fading channel to a receiving unit wherein the received portion of the main signal is detected and an estimation is made of the frequency response of the fading channel using the coded pilot signal portion of the transmitted signal. The detected received main signal and the estimated channel frequency response are then used to estimate the signal. This determination may be based upon a channel inversion of the frequency response or new channel estimation combined with maximum likelihood sub-sequence estimation.
90 Citations
17 Claims
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1. A method for improving channel estimation over a fast fading channel, comprising the steps of:
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generating a coded OFDM signal including a main signal portion coded using a first signal code and a pilot signal portion coded using a second signal code; transmitting the coded OFDM signal over a fading channel; detecting a received main signal within the coded OFDM signal; detecting a received pilot signal within the coded OFDM signal; estimating a frequency response of the fading channel carrying the transmitted coded OFDM signal from the detected pilot signal; and determining an estimated received signal from the detected received main signal and the estimated frequency response of the fading channel. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for signal estimation over a fast, fading channel, comprising the steps of:
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generating a coded OFDM signal including a coded main signal portion and a coded pilot signal portion; transmitting the coded OFDM signal over a fading channel; detecting a received main signal within the coded OFDM signal; detecting the pilot signal within the coded OFDM signal; estimating a frequency response of the fading channel carrying the coded OFDM signal from the detected pilot signal; inverting the estimated frequency response of the fading channel; and generating an estimated channel signal from the inverse of the estimated frequency response and the detected received main signal. - View Dependent Claims (9, 10, 11, 12)
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13. A method for improving channel signal estimation over a fast, deep fading channel, comprising the steps of:
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generating a coded OFDM signal including a main signal portion coded using a first signal code and a pilot signal portion coded using a second signal code; transmitting the coded OFDM signal over a fading channel; detecting a received main signal from the coded OFDM signal; detecting a received pilot signal within the coded OFDM signal; estimating a frequency response of the fading channel carrying the transmitted coded OFDM signal from the detected pilot signal;
generating a matrix representing all possible faded subsequences from the estimated frequency response and a list of all possible transmitted sequences;creating a metric enabling selection of an estimated subsequence using the matrix and the received main signal; and selecting an estimated signal subsequence using the metric, the list of possible transmitted subsequences, and the estimated signal subsequences representing the estimated received signal. - View Dependent Claims (14, 15, 16, 17)
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Specification