Energy-efficient relay aided ad hoc networks using iteratively detected irregular convolutional coded, unity-rate coded and Space-Time Trellis Coded transceivers

Abstract

Abstract-The nodes of ad hoc networks are typically batterypowered, hence requiring the employment of energy-efficient schemes. Near-capacity coding schemes allow a single link to communicate using the lowest possible transmit power, while achieving a low Frame Error Ratio (FER). With the same motivation of conserving battery energy, numerous power-aware routing algorithms have been proposed for improving the overall multiuser network's energy-efficiency instead of improving a single link. Taking both these design factors into consideration, we employ Multi-Antenna aided Relays (MA-Rs) in the context of ad hoc networks, which use a three-stage concatenated transceiver constituted by an Irregular Convolutional Code, Unity-Rate Code and Space-Time Trellis Code (IrCC-URC-STTC) equipped with two antennas. All other mobiles are single-antenna assisted nodes and refrain from relaying, hence they dispense with STTC schemes and use a two-stage concatenated IrCC-URC coding scheme. It is confirmed that as expected, in a high-node-density scenario the average energy consumption per information bit and per node becomes about a factor two lower than that in the equivalent Single-Antenna Relay (SA-R) aided networks. I. INTRODUCTIONEnergy-efficient wireless network design has recently attracted wide-spread research attention. Diverse error-resilient Forward Error Correction (FEC) schemes were proposed in [1] for achieving a low Bit Error Ratio (BER) at near-capacity Signal-to-Noise Ratio (SNR) values. Therefore, the effective transmission range can be improved, when the required received signal power is reduced. A novel Distributed Concatenated Irregular Convolutional Coded, Unity-Rate Coded and Space-Time Trellis Coded (DC-IrCC-URC-STTC) scheme has been proposed for cooperative communications in [2]. Several Single-Antenna Relays (SA-Rs) were activated between the source and the destination. The relays roaming closest to their optimal locations were activated based on a novel technique relying on Extrinsic Information Transfer (EXIT) charts in conjunction with near-capacity code design principles.Numerous power-aware routing protocols were proposed in [3] for improving the energy efficiency from a multiuser networking perspective. Moreover, cross-layer optimized power control has been widely exploited [4][5][6][7][8] for maintaining the required target-integrity at a low power in realistic propagation environments. A physical-layer-oriented routing protocol supported by sophisticated power control was proposed in [4] for a Line-Of-Sight (LOS) and shadow faded scenario, where the estimated end-to-end BER of a multi-hop path was used as the route selection metric. Furthermore, an adaptive relaying strategy switching between the Amplify-and-Forward (AF)

Cross-Layer Aided Energy-Efficient Routing Design for Ad Hoc Networks

“…Based on the discussions in the previous sections, the rest of the paper is organized as follows: First, we study the cross-layer aided routing design jointly considering both the PHY layer and the NET layer [72], as shown in Section II; Then in Section III we further investigate the cross-layer aided routing design concept by jointly considering the PHY layer, the DL layer and the NET layer [73,74]. We commence by considering Traditional Routing (TR) relying on a fixed transmit power in Subsection III-A, while TR combined with Power Allocation (PA) is discussed in Subsection III-B and Opportunistic Routing (OR) using PA is studied in Subsection III-C; Finally, Section IV concludes this treatise and offers some design guidelines.…”

“…However, the solution disseminated in [72] aims for minimizing the energy consumption by the joint design of both the PHY and NET layers with the assistance of Multiple-Antenna Aided Relay Nodes (MA-RN), as shown in the system model of Fig. 6.…”

“…In the NET layer, the more efficient DYMO routing protocol [34] is employed, because the DYMO routing protocol imposes a lower network control load and it is more flexible in a high-mobility environment. However, the scenario considered in [72] is a stationary scenario. The investigation of highmobility scenarios was set aside for its future study.…”

“…Specifically, the advantages of near-capacity coding schemes were quantified in terms of their energy saving. A near-capacity three-stage concatenated IrCC-URC-STTC relay-transceiver equipped with two transmit antennas was proposed in [72] for the ad hoc network considered, since it achieved a low FER at a low transmit power. The high effective transmission range of the IrCC-URC-STTC aided MA-RNs facilitated cross-layer design for activating beneficial routes having the lowest number of longer hops.…”

Cross-Layer Aided Energy-Efficient Opportunistic Routing in Ad Hoc Networks

“…We conducted simulations for characterizing the FER performance versus the Signalto-Noise-Ratio (SNR) and followed the approach of [12] for fitting a polynomial to the FER versus SNR curve. The Forward Error Correction (FEC) scheme employed in our paper is an Irregular Convolutional Coded, Unity-Rate Coded and Quadrature Phase-Shift Keying (IrCC-URC-QPSK) [23,24] scheme. The corresponding FER versus SNR curve was generated with the aid of bit-by-bit simulations.…”