  In this paper, we study backscatter communication (BC) for power-limited
devices that are connected to a network for the Internet of Things (IoT), where
joint estimation and detection is carried out at a receiver to detect signals
from a backscatter device (BD) with ambient orthogonal frequency division
multiplexing (OFDM) carrier. In conventional BC, in order to avoid the
difficulty of the carrier estimation, the energy detector is usually considered
at a receiver at the cost of poor performance. To improve the performance, in
this paper, we consider a novel approach that allows the carrier estimation at
the receiver via joint estimation and detection. In particular, in the proposed
approach, the matched-filtering at the BD (for the transmitter filter) is
employed to impose a certain property that allows efficient and reliable
carrier estimation via joint estimation and detection. Through the performance
analysis and simulation results, we show that the matched-filtering at the BD
in the proposed approach can improve the performance.
