doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 1 OQAM performances and complexity IEEE P Wireless RANs Date: Authors: Notice: This document has been prepared to assist IEEE It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chairhttp://standards.ieee.org/guides/bylaws/sb-bylaws.pdf Carl R. StevensonCarl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE Working Group. If you have questions, contact the IEEE Patent Committee Administrator at >

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 2 Simulation parameters –Constellation : 64 –Bandwidth : 7 MHZ –Channel: 641 MHz –Modulation Nb of sub-carriers: 2048 Nb of modulated sub-carriers: 1728 System frequency: 7.68 MHz Guard interval (case of OFDM): 1/16 –Convolutional encoder 64 states – rate ½ G1=171 oct, G2=133 oct

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 3 Profiles

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 4 OFDM with Convolutional FEC

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 5 OQAM with Convolutional FEC

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 6 Convolutional OQAM vs OFDM – Gaussian

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 7 Convolutional OQAM vs OFDM Profile A

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 8 Convolutional OQAM vs OFDM Profile B

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 9 Convolutional OQAM vs OFDM Profile C

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 10 OQAM/IOTA implementation

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 11 OQAM/IOTA extra complexity wrt OFDM Modulator IFFT speed is twice but doesn't require extra hardware. A memory and processing reduction may be envisaged since the IFFT operates real numbers. A 8-taps complex filter with fixed coefficient (16 bits) and 3 symbol delay line memories (6K words of 16 bits) are used to filter the pilots sub-carriers. A 4-taps real filter with fixed coefficient (16 bits) and 3 symbol delay line memories (6K words of 16 bits) are used to realize the IOTA wavform.

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 12 OQAM/IOTA extra complexity wrt OFDM Demodulator IFFT speed is twice but doesn't require extra hardware. A 8-taps complex filter with fixed coefficient (16 bits) and 3 symbol delay line memories (6K words of 16 bits) are used to filter the pilots sub-carriers. A 4-taps real filter with fixed coefficient (16 bits) and 3 symbol delay line memories (6K words of 16 bits) are used to remove the IOTA wavform. Channel estimation and equalisation are identical to OFDM.

doc.: IEEE /0018r0 Submission January 2006 Patrick Pirat, France TelecomSlide 13 OFDM/OQAM channel estimation and equalization Pilot symbols can be inserted in a preamble –Pilot sequence specific to OFDM/OQAM inserted at the beginning of the frame (see slide 29, preamble) Once the channel coefficients have been recovered at pilot position equalization is performed exactly the same way as for conventional OFDM –OFDM/OQAM is designed to limit interference With IOTA filter, quasi no ISI if max delay of the channel < 10~15% of OFDM symbol duration Quasi no Doppler in WRAN –Channel equalization performed with 1 coefficient per sub-carrier (same as OFDM). No additional complexity due to ISI. No need of modification of the matched "IOTA" filter.