Fumihiro Hasegawa

A Novel PAPR Reduction Scheme for SC-OFDM with Frequency Domain Multiplexed Pilots

In this letter, a novel data-pilot multiplexing scheme with reduced peak to average power ratio (PAPR) is introduced for single carrier (SC)-orthogonal frequency division multiplexing (OFDM) systems. In the proposed scheme, phases of SCOFDM symbols are rotated adaptively such that PAPR is reduced and circular shifts are introduced in the time domain (TD). To index the amount of phase rotation applied at the transmitter, a sequence of pilot symbols, which is unique for each phase rotation angle, is chosen from a predetermined set and multiplexed with the phase rotated SC-OFDM symbols in the frequency domain. Simulation results indicate that the proposed method can reduce the PAPR dramatically, and yield superior bit error rate (BER) performance compared to conventional methods.

Novel Dynamic and Static Methods for Out-of-Band Power Suppression in SC-OFDM

Novel dynamic and static out-of-band (OoB) suppression methods for single carrier (SC)-orthogonal frequency division multiplexing (OFDM) are proposed in this letter. In the dynamic approach, symbols at designated positions from the previous block are inserted at predetermined positions in the current block to maintain continuity between blocks. In the static method, a fixed sequence of symbols is inserted in an SC-OFDM block for OoB power suppression. In both approaches, OoB power can be suppressed significantly by controlling design parameters.

A Novel Cyclic Shift Interleaver Design for Linearly Precoded OFDM Systems

In this letter, a design metric of the interleaver is derived from the union bound of the bit error rate (BER) of linearly precoded orthogonal frequency division multiplexing (OFDM) systems, assuming that the power-delay profile of the channel is known at the transmitter. A new cyclic shift interleaving scheme is proposed to improve the BER performance of OFDM systems. The proposed interleaving scheme is parameterized, and it incorporates existing interleaving schemes. The simulation results indicate that the proposed interleavers outperform the existing interleavers by up to 1.5 dB in a practical scenario.

SC-OFDM, a Low-Complexity Technique for High Performance Satellite Communications

Single-Carrier Orthogonal Frequency Division Multiplexing (SC-OFDM) is a transmission technique particularly suitable for satellite transmission due to its low envelope variations and to the advantages brought by its natural compatibility with zero roll-off. Moreover, low complexity per-carrier equalization is possible in the frequency domain. This paper proves the high performance of SC-OFDM transmission over satellite in different use cases and compares this performance with state of the art techniques such as DVB-SX transmission.

Reduction of Out-of-Band Power in SC-OFDM Systems

A new out-of-band power suppression method for SC-OFDM is proposed in this paper. In the proposed method, phase continuity between SC-OFDM blocks is preserved by inserting one static “anchor symbol”. As a result, out-of-band power emissions are reduced without BER performance degradation. Both simulation and experimental results indicate that reduction of out-of-band emissions up to 13dB can be achieved by using the proposed method.

Hierarchical Modulations for Two-Level Transmission against Rain Fades in Satellite Broadcasting

A new family of 64ary hierarchical constellations for two level transmission is investigated in this paper. Constellation design is targeted to offer protection against rain fades for satellite broadcasting applications. This new family of constellations, derived from Amplitude Phase Shift Keying (APSK) designs, has low envelope fluctuations compared to other state of the art hierarchical constellations. It is also proven that it has superior performance compared to other types of two level transmissions such as time sharing.