Rateless coding transmission over multi-state dying erasure channel for SATCOM
Gu et al. EURASIP Journal on Wireless Communications and
Networking
Rateless coding transmission over multi-state dying erasure channel for SATCOM
Shushi Gu 0
Jian Jiao 0
Qinyu Zhang 0
Xuemai Gu 1
0 Communication Engineering Research Center, Harbin Institute of Technology-Shenzhen, The Xili University Town , Nanshan District, Shenzhen 518055 , China
1 School of Electronics and Information Engineering, Harbin Institute of Technology , 92 West Dazhi Street, Nan Gang District, Harbin 150001 , China
Satellite communication (SATCOM) systems have attracted great attention from academic and industrial communities in recent years, and huge amount of data delivery over satellite downlinks is considered as a promising service in emerging 5G networks, such as multimedia broadcasting. Nevertheless, due to intermittent connections from LEO or MEO satellite to earth station, and high dynamic channel conditions over downlinks, satellites may not be able to transmit the large data files to the ground station on time. In this paper, we propose a new rateless coding transmission for multi-state dying erasure channels (MDEC) with random channel life span and time-varying packet error rates, to improve the transmitting capability over SATCOM downlinks. Firstly, a heuristic approach for suboptimal degree distributions based on AND-OR tree technique is presented to achieve higher intermediate performance and lower symbol error rate of our proposed rateless codes. Furthermore, the appropriate code length of the connective window is derived and analyzed for enhanced average throughput on MDEC that is also optimized by maximum problem solving. Simulations have been conducted to evaluate the effectiveness of our rateless coding transmission for large file delivery on dynamic channel conditions. The results demonstrate that our proposed transmission scheme outperforms existing conventional rateless codes with significantly better intermediate performance and throughput performance over unreliable SATCOM downlinks, under time-varying packet error rates and unpredictable occurrences of exhausted energy or cosmic ray attacks.
Satellite communication; Multi-state dying erasure channel; Rateless codes; Degree distribution; Optimal code length
1 Introduction
Satellite communication (SATCOM) systems have
attracted great attention from academic and industrial
communities in recent years, which have been widely
used for many military and civil services, e.g., weather
forecast, environment monitoring, multimedia service,
positioning system, and emergency rescue [1–4]. In
comparison to terrestrial communication, SATCOM systems
have the advantages of larger bandwidth and wider
coverage, for providing the huge amount of data services in the
emerging fifth generation (5G) networks, such as hybrid
satellite-terrestrial communication systems [5, 6].
Nevertheless, satellite systems have significantly
different link characteristics than terrestrial links [7]. Firstly,
since low earth orbit (LEO) or medium earth orbit (MEO)
satellites (SA) fly along their own orbits and have very
limited contact time with earth stations (ES), there is no
sufficient contact time between SA and ES to download
all data information [8]. Besides, the satellite downlink
channel conditions are indeed time-varying due to
atmospheric precipitation impacting high-frequency bands, so
the time invariance assumption no longer holds [9].
Furthermore, the telecommunication systems on satellite may
be subjected to serious effects, including the lack of
battery energy and the attack of solar winds or cosmic rays,
so that the communication links between SAs and ESs
would randomly break down unpredictably. The above
situations make great difficulties for the large amount of data
transmitted back to the ground on the downlink
channels. Therefore, it is necessary to give a theoretical channel
model to describe the extremely dynamic characteristics
on SATCOM channel, as well as to design an efficient
and reliable transmission technique for large satellite data
service downloading.
In [10], the authors firstly investigate a special type of
channel with a finite and random channel length, termed
dying channel. This type of channel may suddenly
terminate due to communication links subjected to random
fatal impacts, e.g., the sensor node may run out of power
or be destroyed by fire attacks of military equipments
in hostile environment, and the communication systems
embedded in biological cells that may disappear
unpredictably, due to excretion and digestion. It is critical to
quantify how fast and reliably the information can be
collected over this attacked channels with finite channel life
span. Dying channels are modeled as the finite-state
semiMarkov channels in [11]. It proves that lower Shannon
limit which is very close to zero is almost reached on
discrete memoryless channel that dies, so that arbitrarily
small probability of error is not achievable. The authors
optimize the seque (...truncated)