Inter-Relay Interference Mitigation for Chirp-Based Two-Path Successive Relaying Protocol

Abstract

Since the chirp spread spectrum (CSS) system is considered as a communication technology for the Internet of things (IoT), long-range communication and a high data rate are required. In wireless communications, in order to increase spectral efficiency and to extend transmission coverage, a two-path successive relaying (TPSR) protocol has been proposed. Thus, in order to improve transmission performance of the CSS system, in this paper we apply the TPSR protocol to the CSS system. However, since the TPSR protocol is successively relaying data, the spectral efficiency may be limited due to inter-relay interference (IRI). Hence, we propose a multiple linear chirp-based IRI mitigation method for the CSS-based TPSR protocol. In the proposed scheme, the cross-correlation coefficient (CCC) has been derived mathematically according to a separating bandwidth in a given total bandwidth. Then, one separating bandwidth that guarantees the transmission performance is allocated to the primary relay by considering a single relay CCC (SR-CCC) and another separating bandwidth that guarantees the orthogonality from the primary relay is allocated to the secondary relay by considering the inter-relay CCC (IR-CCC). Since the IR-CCC means a degree of similarity between these two relays, it is possible to mitigate the IRI effect within the same bandwidth by allocating orthogonal separating bandwidths to each relay. Simulation results show that the proposed scheme can improve the transmission performance by mitigating the IRI effect even in high IRI environments. Consequently, we expect that the proposed scheme can extend the transmission coverage and increase the data rate of the CSS system.

Interference Management in 5G and Beyond Network: Requirements, Challenges and Future Directions

“…As a consequence, the simulation results achieved accurate expression for the system OP and evaluated the influence of RSI and hardware impairment on system performance to overcome inadequacies of earlier related works. In [131], the authors examine the IRI issue in the CSS TPSR protocol. It focuses on MLC signals for IRI mitigation, whereas simulation results validate the suggested method's BER performance.…”

Emerging Technologies for Future Sensor Networks—Selected Papers from ICGHIT 2019

“…In addition, the two-path successive relaying (TPSR) protocol has been proposed in order to increase spectral efficiency and to extend IoT devices’ transmission coverages. The CSS-based TPSR protocol for IoT system is proposed in a paper, titled: “Inter-Relay Interference Mitigation for Chirp-Based Two-Path Successive Relaying Protocol” [1]. In the paper, the cross-correlation coefficient (CCC) has been derived mathematically according to a separating bandwidth in a given total bandwidth.…”

Agricultural monitoring system using images through a LPWAN network

“…It is possible to find optical communication systems such as [163][164][165][166], and deep learning techniques in order to do more efficient a communications networks [167,168]. Moreover, there are documents that refer to spectral efficiency [169], multiple in multiple output MIMO [170], modulation scheme systems [171], Orthogonal Frequency-Division Multiple Access-OFDM systems [172], Wireless sensor network WSN [173], Narrow Band IoT [174] and mechanisms to improve a high data rate [169,175]. All of the above aim to enhance or increase the data rate in wireless systems, particularly some of them in applications with LPWAN communications systems such as LoRa technology.…”