Efficient Polar Coded Selective Decode-and-Forward with Cooperative Decision Threshold in Cooperative Multi-Relay...

Area of Science:

• Satellite communications
• Wireless networking
• Information theory

Background:

• Satellite Internet of Things (IoT) devices face poor direct channel quality due to terrain shielding.
• Cooperative communication with multiple relays is necessary to overcome signal degradation.
• Existing decode-and-forward (DF) methods suffer from error propagation in such scenarios.

Purpose of the Study:

• To propose an efficient polar coded selective decode-and-forward (SDF) cooperation method.
• To mitigate error propagation in multi-relay cooperative satellite IoT systems.
• To enhance bit error rate (BER) and outage probability (OP) performance.

Main Methods:

• A novel decision threshold is derived from channel state information (CSI), exploiting the optimal relay-destination (R-D) link gain ratio.
• Cooperative SDF transmission is activated when relay link quality exceeds the threshold; otherwise, direct transmission or retransmission is used.
• A polar code is designed for fading channels and adaptively adjusted for optimal BER performance.

Main Results:

• The proposed polar coded SDF (PCSDF) scheme demonstrates significant performance gains.
• Achieved approximately 0.9 dB and 0.5 dB gains at a BER of 10-4 compared to non-cooperation and existing polar coded cooperation.
• Improved BER and outage probability (OP) in multi-relay cooperative systems with multi-path fading channels.

Conclusions:

• The PCSDF scheme effectively addresses error propagation in cooperative satellite IoT.
• It offers enhanced reliability and efficiency for sixth-generation (6G) communications in heterogeneous networks.
• The method is well-suited for satellite IoT applications requiring robust communication links.