Computationally Efficient Residual Symbol Timing Offset (STO) Estimation Scheme for OFDM-based DRM plus Systems

One of the main limitations of orthogonal frequency division multiplexing (OFDM) is its sensitivity to symbol timing offset (STO) because it is difficult to obtain an accurate interpolation between the pilot subcarriers in the presence of a residual STO. This paper proposes a low complexity STO estimation scheme in OFDM based digital radio mondiale plus (DRM+) system. To this end, the pilot symbols used for STO estimation in the DRM+ system are partitioned into a number of pilot subsets, and pilots in each subset are phase-rotated to have a unique phase so that the estimator is made computationally efficient. Via computer simulation, such a design achieves not only a low computational load but also comparable performance, when compared to the conventional STO estimation scheme.