Transmit diversity from orthogonal design for fbmc/oqam

Abstract

The invention relates to how to apply an Alamouti like space-time coding (or transmit diversity) to a Filter Bank Multicarrier (FBMC) transmission using Offset QAM (OQAM). In FBMC, due to the orthogonality in the real domain only, an intrinsic interference results thereof for the imaginary component. Simply adapting the Alamouti scheme to FBMC OQAM is not obvious since the intrinsic interference terms are not equivalent at each antenna since it depends on the surrounding symbols. The application proposes to choose contiguous precoding symbols such that a virtual PAM Alamouti scheme is achieved. Code rates of 1 / 2 or 2 / 3 are achieved depending on the number of precoding symbols needed per antenna.

Description

technical field [0001] The present technology relates to methods and apparatus for transmitting a multi-carrier signal, wherein the signal is of the Offset Quadrature Amplitude Modulation (OQAM) type comprising symbols in time-frequency space, wherein the symbols comprise data and precoding symbols. Background technique [0002] Transmit diversity is considered important because it can be applied at the sender side to improve the reliability of the communication link even if channel state information is not available at the sender. This includes high speed mobile scenarios where the feedback information from the receiver to the transmitter becomes outdated quickly, and also broadcast scenarios. [0003] The Alamouti codes described in "A simple transmit diversity technique for wireless communications" by S.M. Alamouti, IEEE Journal on Select Areas in Communications, Vol. 16, No. 8, October 1998 are derived from an orthogonal design for two transmit antennas A common transm...

AI Technical Summary

Problems solved by technology

This explains the problem that transmit diversity from an orthogonal design according to the Alamouti coding scheme cannot be applied to FBC / OQAM in a straightforward manner

Zero symbols result in a rate loss

Furthermore, the applicability of this scheme may be limited since the channel must be constant over multiple blocks, which may not hold for many propagation scenarios (e.g. mobile scenarios)

[0043] All in all, there is not yet any scheme in the literature that achieves an orthogonal design without rate penalty

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