de la PROfessional Mobile Radio large bande basée sur la modulation FILter Bank MultiCarrier Evolution of the Wideband Professional Mobile Radio Based on the Filter Bank MultiCarrier Modulation • ANR Project with Cassidian, CEA-Leti, TeamCast and CentraleSupélec • CentraleSupélec’s part: Blind equalization in FBMC for PMR Networks
for police, firefighters, ambulances … • Transmission of 2G-like data TV GSM WiFi Currently: frequency 380 - 395 MHz radio Standard TETRA -TETRAPOL TV GSM WiFi
the data stream (2/2) 2 steps: 1) The channel H is estimated on pilot tones 2) The signal is equalized with a one-tap per-carrier channel inversion F = 1/Ĥ Unknown channel
[4] (1/4) p 0 m n Simple implementation POP Pair of pilots (POP) [3] Simple implementation Good spectral efficiency (same as OFDM) Weak performance [c1] noise variance interference variance channel variance
[2], [3], [4] (2/4) m n AP Auxiliary pilot (AP) [4] Good spectral efficiency Cancellation of the interference (elegantly) High complexity at transmitter
in OFDM/OQAM [2], [3], [4] (4/4) m n IAM Reduction of the noise and interference energy p+ Interference approximation method (IAM) [2] Reduction of the noise and interference energy Simple implementation Loss of spectral efficiency Good performance [c1]
in LTE … … 1 RB in proposed scheme Application to PMR band: some changes in the LTE PHY parameters [c4] (2/3) … … 2τ0 … … … … … … … TOFDM 15 KHz 5 KHz added subcarrier a. LTE pilot distribution b. Proposed rectangular distribution
LTE PHY parameters [c4] (3/3) 1 RB Channel estimation along the whole band pilot time frequency frequency PMR signals BB BB PMR signal added carriers frequency More flexibility Good channel estimation over each sub-band
symbols, 3 MHz bandwidth - reference in OFDM in LTE: 4.8 Mbits.s-1 - Proposed scheme: Similar to LTE Enable high bit rate applications, as video streaming
Transmitted signal Received signal Recovered signal H F x y w z a + AFB Channel Blind equalizer - Goal: achieve H.F =1 - Constraint : limited knowledge of the signal feature H F + AFB
T PPN … … … … y0,n y1,n ym,n yM-1,n INPUT Equal. am,n Fm,n - Goal: Solve the optimization problem yM-1,n - How? Use the stochastic gradient with - µ is the step-size parameter - J a given cost function 2 degrees of freedom
are investigated: Can be reconsidered [c5] Can be adapted to OFDM/OQAM [c6], [c7] New blind receiver design AFB F F T PPN … … … … y0,n y1,n ym,n yM-1,n INPUT Equal. am,n Fm,n
Filter for Filter Bank Based Multicarrier Transmission,” in proc. Of ICASSP, vol. 4, Salt Lake City, UT, May 2001, pp. 2417 – 2420. [2] E. Kofidis, D. Katselis, A.Rontogiannis, and S. Theodoridis, “Preamble-based channel estimation in OFDM/OQAM systems: A review,” Signal Processing, Elsevier, vol. 93, pp. 2038 – 2054, January 2013. [3] C. Lélé, J.-P. Javaudin, R. Legouable, A. Skrzypczak, and P. Siohan, “Channel estimation methods for preamble-based OFDM/OQAM modulations,” European Transactions on Telecommunications, vol. 19, no. 7, pp. 741 –750, November 2008. Transactions on Telecommunications, vol. 19, no. 7, pp. 741 –750, November 2008. [4] J.-P. Javaudin, D. Lacroix, and A. Rouxel, “Pilot-Aided Channel Estimation for OFDM/OQAM,” in VTC’03 - Spring, vol. 3, Jeju, Korea, April 2003, pp. 1581 – 1585. [5] D. N. Godard, “Self-Recovering Equalization and Carrier Tracking in Two- Dimensional Data Communication Systems,” IEEE Transactions on Communications, vol. com-28, no. 11, pp. 1867 – 1875, November 1980. [6] B. Farhang-Boroujeny, “Multicarrier Modulation With Blind Detection Capability Using Cosine Modulated Filter Banks,” IEEE Transactions on Communications, vol. 51, no. 12, pp. 2057 – 2070, December 2003. [7] A. Goupil and J. Palicot, “New Algorithms for Blind Equalization: The Constant Norm Algorithm Family,” IEEE Transactions on Signal Processing, vol. 55, no. 4, pp. 1436 – 1444, April 2007.
Analysis and LMMSE Application for Preamble-Based Channel Estimation in OFDM/OQAM Systems,” [c2] V. Savaux, F. Bader, Y. Louët “A Joint MMSE Channel and Noise Variance Estimation for OFDM/OQAM Modulation,” [c3] L. Caro, V. Savaux, D. Boiteau, M. Djoko-Kouam, Y. Louët “Preamble-Based LMMSE Channel Estimation in OFDM/OQAM Modulation,” in proc of VTC’15 Spring, Glasgow, May 2015 Glasgow, May 2015 [c4] V. Savaux, F. Bader “Pilot Adaptation for Broadband LTE-Like FBMC System in PMR Band,” in proc of VTC’15 Spring, Glasgow, May 2015 [c5] V. Savaux, F. Bader, J. Palicot “Frequency Blind Equalization Using Constant Norm Algorithm for OFDM Systems,” [c6] V. Savaux, F. Bader “Sub-Optimal Initialization for Blind Equalization with Fast Convergence in OFDM/OQAM Modulation,” [c7] V. Savaux, F. Bader “Enhancing the Constant Modulus Algorithm for Blind Equalization in OFDM/OQAM Modulation,”