	US 11,722,348 B2
	Hybrid reference signal with low PAPR for DFT-S-OFDM
Arnaud Bouttier, Rennes (FR)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 17/639,520
Filed by MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
PCT Filed Oct. 20, 2020, PCT No. PCT/JP2020/040026 § 371(c)(1), (2) Date Mar. 1, 2022, PCT Pub. No. WO2021/090716, PCT Pub. Date May 14, 2021.
Claims priority of application No. 19306433 (EP), filed on Nov. 5, 2019.
Prior Publication US 2022/0294680 A1, Sep. 15, 2022
Int. Cl. H04L 27/26 (2006.01); H04J 13/00 (2011.01)

CPC H04L 27/2636 (2013.01) [H04J 13/0062 (2013.01); H04L 27/2607 (2013.01); H04L 27/2613 (2013.01)]

18 Claims

1. A method for transmitting at least a group of Kd data samples in a radio signal to be transmitted over a communication system, said radio signal being intended to be emitted by an emitter comprising at least one transmission module configured for transmitting on at least a number of K different sub-carriers, K and Kd being strictly positive integers, Kd being strictly smaller than K, said radio signal being provided by:

determining a first position J1 and a second position J2 in a block of K samples (A₀; . . . ; A_K−1), such that the block of K samples comprises:

Kd data samples to be transmitted;

and K0 consecutive samples (A_J1; . . . ; A_J2);

with J2−J1+1=K0 and Kd+K0=K;

applying a DFT-spread-OFDM-type scheme to the block of K samples A=(A₀; . . . ; A_K−1), and obtaining an output signal representing a symbol comprising N complex samples S_nin the radio signal, with n=0 to N−1;

determining, in the output signal, a first position T1 and a second position T2 based on J1, J2, K and N such that:

T2−T1=R, with R being a strictly positive integer;

setting, in the output signal, the values of the R complex samples (S_T1; . . . ; S_T2) between the first position T1 and the second position T2 to zero to obtain an updated output signal;

the method being characterized by:

inserting, between the first position T1 and the second position T2 of the updated output signal, S reference samples, S being a strictly positive integer and R=S+L, with L being a positive or null integer, to obtain a subsequent signal representing a hybrid symbol comprising:

for each of n=[0; T1−1]∪[T2+1; N−1], a complex sample S_nin the radio signal, the complex samples forming a data section of the hybrid symbol;

for each of n=[T1+L; T2], a reference sample RS_nin the radio signal, the reference samples forming a reference section of the hybrid symbol;

appending, to the hybrid symbol, G samples forming a cyclic prefix of at least part of the hybrid symbol to obtain a signal representing the hybrid symbol appended with the cyclic prefix; in view of transmitting the radio signal corresponding to the signal representing the hybrid symbol appended with the cyclic prefix.