Embedded Delay-Doppler Channel Estimation for Orthogonal Time Frequency Space Modulation

Orthogonal time frequency space (OTFS) modulation was shown to provide significant error performance advantages over orthogonal frequency division multiplexing (OFDM) over delay–Doppler channels. The channel impulse response is needed at the receiver to perform OTFS detection. In this work, we analyze OTFS-based channel estimation using a pilot symbol embedded in the data frame: the pilot symbol with a number of guard zero-symbols is suitably located on the delay–Doppler grid containing the information symbols. Different symbol arrangements are proposed depending on whether the channel has integer or fractional Doppler paths relative to an integer grid. The channel information is first estimated from a group of received symbols using a simple threshold method. The estimated information is then used for data detection within the same frame, via a message passing (MP) algorithm. Numerical results compare the error performance of the proposed schemes and the OTFS scheme with ideal channel estimation under similar spectral and energy efficiency. Moreover, our results show that OTFS with non-ideal channel estimation can still outperform OFDM with ideal channel estimation.

[1]  W. C. Jakes,et al.  Microwave Mobile Communications , 1974 .

[2]  R.哈达尼,et al.  OTFS methods of data channel characterization and uses thereof , 2015 .

[3]  David Tse,et al.  Fundamentals of Wireless Communication , 2005 .

[4]  Peng Li,et al.  A Simple Two-stage Equalizer With Simplified Orthogonal Time Frequency Space Modulation Over Rapidly Time-varying Channels , 2017, ArXiv.

[5]  Akbar M. Sayeed,et al.  Delay-Doppler channel estimation with almost linear complexity: To Solomon Golomb for the occasion of his 80 birthday mazel tov , 2012, 2012 IEEE International Symposium on Information Theory Proceedings.

[6]  Ananthanarayanan Chockalingam,et al.  MIMO-OTFS in High-Doppler Fading Channels: Signal Detection and Channel Estimation , 2018, 2018 IEEE Global Communications Conference (GLOBECOM).

[7]  M. Tsatsanis,et al.  OTFS-ORTHOGONAL TIME FREQUENCY SPACE A Novel Modulation Technique meeting 5 G High Mobility and Massive MIMO Challenges , 2016 .

[8]  Candice King,et al.  Fundamentals of wireless communications , 2013, 2013 IEEE Rural Electric Power Conference (REPC).

[9]  Emanuele Viterbo,et al.  Low Complexity Iterative Rake Detector for Orthogonal Time Frequency Space Modulation , 2018, 2020 IEEE Wireless Communications and Networking Conference (WCNC).

[10]  Ananthanarayanan Chockalingam,et al.  On OTFS Modulation for High-Doppler Fading Channels , 2018, 2018 Information Theory and Applications Workshop (ITA).

[11]  Yi Hong,et al.  Interference Cancellation and Iterative Detection for Orthogonal Time Frequency Space Modulation , 2018, IEEE Transactions on Wireless Communications.

[12]  Yi Hong,et al.  Low-complexity iterative detection for orthogonal time frequency space modulation , 2017, 2018 IEEE Wireless Communications and Networking Conference (WCNC).

[13]  A. Robert Calderbank,et al.  Orthogonal Time Frequency Space Modulation , 2017, 2017 IEEE Wireless Communications and Networking Conference (WCNC).