TY - JOUR
T1 - Error correction for low power sensors in asynchronous communication
AU - Yi, Chen
AU - Kliewer, Jörg
N1 - Funding Information:
This paper was presented in part at the 9th International Symposium on Turbo Codes and Iterative Information Processing [1] . This work was supported in part by U.S. National Science Foundation grant ECCS-1407910 .
Funding Information:
This paper was presented in part at the 9th International Symposium on Turbo Codes and Iterative Information Processing [1]. This work was supported in part by U.S. National Science Foundation grant ECCS-1407910.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/5
Y1 - 2021/5
N2 - We propose a forward error correction scheme for asynchronous sampling via level crossing (LC) sampling and time encoding, where the dominant errors consist of pulse deletions and insertions, and where encoding is required to take place in an instantaneous fashion. For LC sampling the presented scheme consists of a combination of an outer systematic convolutional code, an embedded inner marker code, and power-efficient frequency-shift keying modulation at the sensor node. Decoding is first obtained via a maximum a-posteriori (MAP) decoder for the inner marker code, which achieves synchronization for the insertion and deletion channel, followed by MAP decoding for the outer convolutional code. Besides investigating the rate trade-off between marker and convolutional codes, we also show that residual redundancy in the asynchronously sampled source signal can be successfully exploited in combination with redundancy only from a marker code. This provides a low complexity alternative for deletion and insertion error correction compared to using explicit redundancy. For time encoding, only the pulse timing is of relevance at the receiver, and the outer channel code is replaced by a quantizer to represent the relative position of the pulse timing. Numerical simulations show that LC sampling outperforms time encoding in the low to moderate signal-to-noise ratio regime by a large margin.
AB - We propose a forward error correction scheme for asynchronous sampling via level crossing (LC) sampling and time encoding, where the dominant errors consist of pulse deletions and insertions, and where encoding is required to take place in an instantaneous fashion. For LC sampling the presented scheme consists of a combination of an outer systematic convolutional code, an embedded inner marker code, and power-efficient frequency-shift keying modulation at the sensor node. Decoding is first obtained via a maximum a-posteriori (MAP) decoder for the inner marker code, which achieves synchronization for the insertion and deletion channel, followed by MAP decoding for the outer convolutional code. Besides investigating the rate trade-off between marker and convolutional codes, we also show that residual redundancy in the asynchronously sampled source signal can be successfully exploited in combination with redundancy only from a marker code. This provides a low complexity alternative for deletion and insertion error correction compared to using explicit redundancy. For time encoding, only the pulse timing is of relevance at the receiver, and the outer channel code is replaced by a quantizer to represent the relative position of the pulse timing. Numerical simulations show that LC sampling outperforms time encoding in the low to moderate signal-to-noise ratio regime by a large margin.
KW - Asynchronous sampling
KW - Deletion channels
KW - Error correcting codes
KW - Insertion channels
KW - Joint source-channel coding
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U2 - 10.1016/j.sigpro.2020.107946
DO - 10.1016/j.sigpro.2020.107946
M3 - Article
AN - SCOPUS:85098567981
VL - 182
JO - Signal Processing
JF - Signal Processing
SN - 0165-1684
M1 - 107946
ER -