Incremental Decode-and-forward Research Articles

Energy Consumption Analysis of Beamforming and Cooperative Schemes for Aircraft Wireless Sensor Networks

In this paper, the eight schemes for aircraft wireless sensor networks are investigated, which are single-hop array beamforming schemes (including analog beamforming (ABF), and digital beamforming (DBF)), non-cooperative schemes (including single-hop and multi-hop schemes), cooperative schemes (including amplify and forward (AF), decode and forward (DF)), and incremental cooperative schemes (incremental decode and forward (IDF), and incremental amplify and forward (IAF)). To set up the aircraft wireless communication environment, we design the aircraft channel model by referring to the experimental parameters of the ITU (International Telecommunication Union)-R M.2283, which is composed of path loss, shadowing fading, and multi-path fading channel responses. To evaluate the performance, the conditions energy consumption and throughput analysis are performed. Through simulation results, the incremental cooperative scheme outperformed by 66.8% better at spectral efficiency 2 than the DBF scheme in terms of the energy consumption metric. Whereas, in terms of throughput metric, overall SNR (signal-to-noise ratio) ranged from −20 to 30 dB the beamforming scheme had the best performance in which the beamforming scheme at SNR 0 dB achieved 85.4% better than the multi-hop scheme. Finally, in terms of normalized throughput metric in low SNR range between −20 and 1 dB the ABF scheme had the best performance over the others in which the ABF at SNR 0 dB achieved 75.4% better than the multi-hop scheme. Whereas, in high SNR range between 2 and 30 dB the IDF scheme had the best performance in which the IDF at SNR 10 dB achieved 62.2% better than the multi-hop scheme.

Incremental Relaying for Power Line Communications: Performance Analysis and Power Allocation

In this paper, incremental decode-and-forward (IDF) and incremental selective decode-and-forward (ISDF) relaying are proposed to improve the spectral efficiency of power line communication. Contrary to the traditional decode-and-forward (DF) relaying, IDF and ISDF strategies utilize the relay only if the direct link ceases to attain a certain information rate, thereby improving the spectral efficiency. The path gain through the power line is assumed to be log-normally distributed with high distance-dependent attenuation and the additive noise is from a Bernoulli-Gaussian process. Closed-form expressions for the outage probability, and approximate closed-form expressions for the end-to-end average channel capacity and the average bit error rate for binary phase-shift keying are derived. Furthermore, a closed-form expression for the fraction of times the relay in use is derived as a measure of the spectral efficiency. Comparative analysis of IDF and ISDF with traditional DF relaying is presented. It is shown that the IDF is a specific case of ISDF and can obtain optimal spectral efficiency without compromising the outage performance. By employing power allocation to minimize the outage probability, it is realized that the power should be allocated in accordance with the inter-node distances and channel parameters.

Energy-per-bit performance analysis of relay-based visible-light communication systems

Relaying systems, such as amplify-and-forward (AF), decode-and-forward (DF), selective DF (SDF) and incremental DF (IDF) relaying are usually used to ensure high performance and reliability for communication systems. A comprehensive energy efficiency performance study for different half-duplex relaying protocols, namely DF, SDF and IDF over visible light communication (VLC) channels is provided in this paper. Accurate analytical expressions for both outage probability and the minimum energy-per-bit performance of the aforementioned relaying systems are derived. For the sake of comparison and to justify the use of relays in the proposed system, the performance of a single-hop scenario is analyzed and compared to the relay-based links. The accuracy of the analysis is verified by Monte Carlo simulations. The results reveal that the single-hop VLC system offers the poorest performance compared to that offered by VLC relay-based systems particularly for relatively high end-to-end distances. However, the best performance is offered by SDF and IDF schemes as they have a lower outage probability than other systems under consideration. This work also shows that the performance of the systems under consideration is affected by some parameters, such as the vertical distance to user plane and the maximum cell radius of the LED.

On the Performance of Cooperative Transmission Schemes in Industrial Wireless Sensor Networks

This paper studies the performance of six transmission schemes, namely single-hop, multihop, selective decode-and-forward, amplify-and-forward, incremental decode-and-forward (IDF), and incremental amplify-and-forward (IAF) schemes. For a fair comparison, these schemes are constrained in terms of maximum outage probability and end-to-end throughput. In this paper, we investigate the impact of propagation channel conditions including both line-of-sight and non-line-of-sight environments by exploiting Nakagami-m fading channel. Our simulation results show that, by utilizing a return channel, the IDF and IAF cooperative schemes achieve better performance than the other schemes in most cases.

Energy-Per-Bit Performance Analysis of Relay-Assisted Power Line Communication Systems

This paper provides a comprehensive analysis of the energy efficiency performance for different relaying schemes over the non-Gaussian power line communication (PLC) channel. Specifically, amplify-and-forward (AF), decode-and-forward (DF), selective DF (SDF) and incremental DF (IDF) relaying systems are investigated. For a more realistic scenario, the power consumption profile of the PLC modems is assumed to consist of both dynamic and static power. For each system, we derive accurate analytical expressions for the outage probability and the minimum energy-per-bit performance. For the sake of comparison and completeness as well as to quantify the achievable gains, we also analyze the performance of a single-hop PLC system. Monte Carlo simulations are provided throughout this paper to validate the theoretical analysis. Results reveal that AF relaying over the non-Gaussian PLC channel does not always enhance the performance and that the IDF PLC system offers the best performance compared to all other schemes considered. It is also shown that increasing the channel variance, which is related to the PLC network branching, and impulsive noise probability can considerably deteriorate the system performance. Furthermore, when the end-to-end distance is relatively small, it is found that the single-hop PLC approach can perform better than AF relaying.

Outage performance of cognitive DF relaying networks employing SWIPT

In this paper, the outage performance of a cognitive relaying network over Nakagami-m fading channels, employing simultaneous wireless information and power transfer (SWIPT) technology is analyzed and evaluated. The operation of this network is considered in conjunction with the conventional decode-and-forward (DF) and incremental DF (IDF) protocols. For the conventional DF protocol, it is assumed that there is no direct link between the secondary transmitter (S) and the secondary destination (D), while (for both protocols) after harvesting energy, the relay node (R) always helps to forward the resulting signal to D. However, for the IDF protocol, R assists in relaying S’s information to D only when the direct communication between S and D has failed. Furthermore, for both DF and IDF protocols, we assume there is no power supply for R, and R harvests energy from the transmitted signal of S. We derive exact analytical expressions for the outage probability at D in DF and IDF protocols, respectively, in terms of the bivariate Meijer’s G-function. Performance evaluation results obtained by means of Monte-Carlo simulations are also provided and have validated the correctness of the proposed analysis.

Performance Analysis of Wireless Powered Incremental Relaying Networks With an Adaptive Harvest-Store-Use Strategy

In this paper, we consider a wireless powered cooperative network, in which a source with constant power supply communicates with a destination under the assistance of an energy harvesting (EH) relay. From signals of the source, the relay can perform EH and information decoding simultaneously by using the power splitting (PS) technique. To increase the spectrum efficiency of the system and save energy consumption at the relay, an incremental decode-and-forward (IDF) relaying protocol is adopted to forward information. Inspired by the features of the IDF protocol, we propose a new energy harvesting and use strategy, named adaptive harvest-store-use (AHSU). In this proposed strategy, the relay adaptively sets its PS ratio according to a one-bit feedback from the destination, the channel estimation result for the source-to-relay link, and the relay’s energy status. A finite-state Markov chain (MC) is employed to model the charging/discharging behavior of the relay’s battery. The steady-state distribution of the MC is first derived, and then used to calculate the exact outage probability. In order to gain further insights, we investigate the outage performance of the system when the transmit signal-to-noise ratio of the source is high. Based on the asymptotic outage probability expression, the diversity order and coding gain are characterized, which demonstrates that a full diversity order is achieved by our proposed AHSU strategy in the considered network.

Outage Performance for IDF Relaying Mobile Cooperative Networks

Cooperative communication has emerged as a key technique in fifth generation (5G) mobile wireless networks. In this paper, with incremental decode-and-forward (IDF) relaying and transmit antenna selection (TAS), we investigate the outage probability (OP) performance of mobile cooperative networks. Exact closed-form expressions for OP with optimal TAS are derived. These expressions are used to evaluate the impact of power allocation on OP performance. Then we verify the mathematical derivations using Monte Carlo simulations. The OP performance is influenced by power-allocation parameter.

Performance evaluation of multi-hop relaying over non-gaussian PLC channels

Relaying over power line communication (PLC) channels can considerably enhance the performance and reliability of PLC systems. This paper is dedicated to study and analyze the energy efficiency of multi-hop cooperative relaying PLC systems. Incremental decode-and-forward (IDF) relying is exploited to reduce the transmit power consumption. The PLC channel is assumed to experience log-normal fading with impulsive noise. The performances of single-hop and conventional DF relaying systems are also analyzed in terms of outage probability and energy efficiency for which analytical expressions are derived. Results show that using more relays can improve the outage probability performance; however, this is achieved at the expense of increased power consumption due to the increased static power of the relays, especially when the total source-to-destination distance is relatively small. Results also demonstrate that the IDF PLC system has better energy efficiency performance compared to the other schemes.

Incremental relaying cooperative networks with dual transmit diversity

This paper studies the performance of cooperative wireless networks using incremental-relaying and dual transmit diversity with the simple orthogonal space time block coding (OSTBC) scheme. The proposed model is studied by utilizing different relaying schemes including decode and forward (DF), amplify and forward (AF), and adaptive incremental-relaying (i.e., best relay selection) with DF relaying. In particular, upper-bounded expressions are derived for the averagebit error rate (BER), signal to noise ratio (SNR) outage probability, average achievable rate, and normalized throughput. Detailed results show that the dual transmit diversity approach outperforms the regular incremental relaying cooperative diversity scheme in terms of transmission power and channel efficiency for the same transmit power. Moreover, best relay selection with multiple relaying nodes outperforms fixed incremental DF relaying, especially for lower transmitted SNR values.

Characterization of IDF and SDF Relaying Protocols in SSK Modulation Systems

In this paper, the performance of space shift keying (SSK) modulation is investigated in a cooperative communication system, using incremental decode-and-forward (IDF) and selective decode-and-forward (SDF) relays. The IDF and SDF relays use instantaneous signal-to-noise ratio (SNR) to verify the quality of received signal, which is not applicable to SSK modulation. In addition to instantaneous SNR, channel coefficients play the main role in the performance of SSK modulation. Moreover, in this modulation scheme, the active channel coefficient is unknown. In this paper, instead of instantaneous SNR, a new reliable criterion is introduced to be used in the IDF or SDF protocols for SSK modulation. This criterion is based on the Euclidean distances between active channel coefficient and other inactive channel coefficients. The analytical expressions are derived to calculate the average bit error rate (ABER) and the power consumptions in a cooperative system, over Rayleigh fading channels, for both IDF and SDF relaying protocols. There is good agreement between the Monte Carlo simulated and analytical results. These results show that this Euclidean distance-based criterion, in IDF or SDF relaying protocols, improves cooperative diversity gain and the ABER performance significantly.

Performance Analysis of IDF Relaying M2M Cooperative Networks over N-Nakagami Fading Channels

Exact average bit error probability (BEP) expressions for mobile-relay-based mobile-to-mobile (M2M) cooperative networks with incremental decode-and-forward (IDF) relaying over N-Nakagami fading channels are derived in this paper. The average BEP performance under different conditions is evaluated numerically to confirm the accuracy of the analysis. Results are presented which show that the fading coefficient, the number of cascaded components, the relative geometrical gain, and the power allocation parameter have a significant influence on the average BEP performance.

Performance Analysis of SNR-Based Incremental Hybrid Decode-Amplify-Forward Cooperative Relaying Protocol

In this paper, we propose and analyze a new relaying scheme for the three-node cooperative relaying system, named as incremental hybrid decode-amplify-forward relaying (IHDAF), where the relay may choose to keep silent or transmit message in decode-and-forward (DF) or amplify-and-forward (AF) mode based on the qualities of the channels among the source, relay, and destination. Closed-form expressions of the outage probability and bit error rate (BER) of the proposed IHDAF protocol are derived. The optimal relationship of the two important signal-to-noise ratio (SNR) thresholds at the relay and destination to decide whether cooperation is necessary and the cooperative mode has been achieved. Moreover, the effects of the power allocation schemes, SNR thresholds, and relay locations on the outage probability and BER of the IHDAF protocol are studied. Theoretical analysis and simulation results show that the IHDAF relaying scheme outperforms the incremental-selective DF (ISDF), incremental DF (IDF), and cooperative STBC schemes, especially when the relay is close to the destination.

Efficient Cooperative Protocols for Full-Duplex Relaying Over Nakagami- <inline-formula> <tex-math notation="TeX">$m$</tex-math></inline-formula> Fading Channels

In this work, efficient protocols are studied for full-duplex relaying (FDR) with loopback interference over Nakagami-m block fading channels. Recently, a selective decode-and-forward (DF) protocol was proposed for FDR, and was shown to outperform existing protocols in terms of outage over Rayleigh-fading channels. In this work, we propose an incremental selective DF protocol that offers additional power savings, yet yields the same outage performance. We evaluate their outage performance over independent non-identically distributed Nakagami-m fading links, and study their relative performance in terms of the signal-to-noise ratio cumulative distribution function via closed-form expressions. The offered diversity gain is also derived. In addition, we study their performance relative to their half-duplex counterparts, as well as known non-selective FDR protocols. We corroborate our theoretical results with simulation, and confirm that selective cooperation protocols outperform the known non-selective protocols in terms of outage. Finally, we show that depending on the loopback interference level, the proposed protocols can outperform their half-duplex counterparts when high spectral efficiencies are targeted.

Secrecy Analysis of Transmit Antenna Selection Cooperative Schemes With No Channel State Information at the Transmitter

In this paper we investigate the physical layer security in a cooperative scenario where the source and the eavesdropper are equipped with multiple antennas, while the relay and the destination are single-antenna devices. We consider that no channel state information (CSI) is available at the transmitter, besides the index of the selected transmit antenna. Closed-form expressions for the secrecy outage probability of the selective decode-and-forward (SDF) and incremental decode-and-forward (IDF) schemes are derived. In addition, we also conduct an asymptotic analysis to get further insights on the performance of each scheme, which predicts a performance floor inherent to the scenario without CSI at the transmitter. Moreover, we also analyze the schemes in terms of the secrecy throughput, which shows that the performance floor that appear in the outage analysis only affects the secrecy throughput if the floor is too high, as is the case of the non-cooperative transmission. Our analysis show that IDF can considerably outperform the SDF and the non-cooperative transmission both in terms of secrecy outage probability and secrecy throughput.

Multiuser incremental decode‐and‐forward relaying under outdated channel estimates

An exact closed-form expression is derived for the outage probability of a recently proposed multiuser, incremental, decode-and-forward (DF) relaying scheme, when affected by outdated channel estimates. In this scheme, one source communicates with the best destination under the assistance of an incremental DF relay, with the direct- and relaying-link signals being merged via maximal-ratio combining. A simple asymptotic expression is also derived for the outage probability, revealing that the outdated channel estimates reduce the system diversity order to two, regardless of the amount of destinations available.

Efficiency Analysis of Different Cooperative Communication Schemes in Wireless Sensor Networks

We compare the energy efficiency of different cooperative communication schemes in wireless sensor networks. By taking into account the energy consumption of the RF circuitry, we show that the incremental decode and forward (IDF) protocol may be considerably more energy efficient than others because a feedback channel is available. We also find that using cooperative transmission too much is not necessarily to improve system performance.

Outage Probability and DMT Performance of Underlay Cognitive Networks with Incremental DF and AF Relaying over Nakagami-m Fading Channels

This letter studies the outage performance of cognitive radio systems with incremental decode-and-forward (DF) and amplify-and-forward (AF) relaying in a Nakagami-m fading environment. The outage behavior and diversity-multiplexing tradeoff (DMT) are investigated. These results indicate that the DMT is irrelevant to the primary user and the secondary system can achieve the full diversity order. Simulation results substantiate the accuracy of our analysis. The presented method/steps for performance evaluation are applicable to other fading channels.

Outage Analysis of Underlay Cognitive Multiple Relays Networks with a Direct Link

In this letter, exact outage probability of decode-and-forward (DF) and incremental DF (IDF) relaying are respectively derived over underlay cognitive relay networks. Particularly, we consider both the direct link and the primary user's (PU's) interference with multiple available relays. Moreover, to reveal additional insights into the performance of DF and IDF relaying, the outage gap between the two schemes is theoretically evaluated. Finally, simulation results validate our analytical studies.

Spectrally Efficient Diversity Exploitation Schemes for Downlink Cooperative Cellular Networks

In this correspondence, we advocate the exploitation of direct links for downlink cooperative cellular networks, where one base station (source) communicates with one out of N mobile users (destinations) by using a half-duplex decode-and-forward (DF) relay. Motivated by the potential spectrum-efficiency enhancement, we propose two spectrally efficient schemes for the diversity exploitation of the considered systems in a homogeneous network topology. By scheduling the user with the best direct link to access the channel, an incremental DF relaying scheme is first presented, and its outage behavior is analyzed, revealing that this scheme can achieve full diversity order (N + 1). To further enhance transmission robustness against fading (in terms of outage probability), an improved scheme is also proposed, which substantially utilizes the opportunistic scheduling mechanism when the direct transmission fails. Outage analysis for this scheme shows that, aside from achieving full diversity order, it can further improve the transmission reliability to fading, compared with the preceding one. In addition, it is indicated that the expected spectral efficiency of the proposed schemes approaches that of direct transmission in the high-signal-to-noise-ratio (SNR) regime. Finally, adjustment of the proposed schemes for heterogeneous network topology is presented, and the corresponding outage behavior is characterized as well.