2 research outputs found
Efficient Ambient LoRa Backscatter with On-Off Keying Modulation
Backscatter communication holds potential for ubiquitous and low-cost
connectivity among low-power IoT devices. To avoid interference between the
carrier signal and the backscatter signal, recent works propose a
frequency-shifting technique to separate these two signals in the frequency
domain. Such proposals, however, have to occupy the precious wireless spectrum
that is already overcrowded, and increase the power, cost, and complexity of
the backscatter tag. In this paper, we revisit the classic ON-OFF Keying (OOK)
modulation and propose Aloba, a backscatter system that takes the ambient LoRa
transmissions as the excitation and piggybacks the in-band OOK modulated
signals over the LoRa transmissions. Our design enables the backsactter signal
to work in the same frequency band of the carrier signal, meanwhile achieving
flexible data rate at different transmission range. The key contributions of
Aloba include: (1) the design of a low-power backscatter tag that can pick up
the ambient LoRa signals from other signals. (2) a novel decoding algorithm to
demodulate both the carrier signal and the backscatter signal from their
superposition. We further adopt link coding mechanism and interleave operation
to enhance the reliability of backscatter signal decoding. We implement Aloba
and conduct head-to-head comparison with the state-of-the-art LoRa backscatter
system PLoRa in various settings. The experiment results show Aloba can achieve
199.4 Kbps data rate at various distances, 52.4 times higher than PLoRa
Poster Abstract: Taming Link-layer Heterogeneity in IoT through Interleaving Multiple Link-Layers over a Single Radio
We propose dynamic reconfiguration of the radio interface in IoT platforms to support multiple link layers simultaneously. This allows us to tackle the increasing link layer heterogeneity in IoT devices, thus bringing a multitude of benefits: extensible and vender agnostic multihop deployments, rapid integration of the new “things” into an existing network, as well as seamless integration of the IoT with the traditional wireless Internet