Selection of channel coding for low-power wireless systems

Abstract

The wireless communications world is moving towards the so-called 4 6 picture, by integrating many different subsystems. Some of them have t o provide short-range connectivity at very low power, in order t o enable hatteryopdrated sensors or devices. This low-power requirement can be achieved by selecting channel codes of high coding gain, However, the power consumption of encoding and decoding operations also has t o be taken into account. This paper analyzes this trade-off between coding gain and digital power consumption, considering different wireless scenarios. It shows that turbo codes can be used even for relatively low-power applications. For very low-power systems, simple Hamming codes provide a good trade-off, as well as convolutional codes. The Golay code is another strong candidate, thanks to a very efflcient implementation. Considering current CMOS technology, the different codes are in competition for systems sending bits with an energy between 0.1 and 10 nJ. Systems working at lower values do not gain anything in coding, while systems working above will always advantageously use turbo-codes.

A Pulsed Coding Technique Based on Optical UWB Modulation for High Data Rate Low Power Wireless Implantable Biotelemetry

“…In addition, it is important to consider that in the proposed architecture, the coding system in the transmitter block does not include any error-correction process that further would improve the BER. In this sense, for example, Hamming and Golay error-correction codes could be considered as suitable solutions to be implemented by an additional low power circuitry enhancing the BER of few orders of magnitude with an additional energy consumption of only 3-4 pJ/bit [19,20]. Figure 5 reports a picture of the overall implemented system together with the related block scheme of the experimental set-up showing its main components.…”

“…In particular, the proposed approach, already investigated in IR-UWB systems [13], implements an optical synchronised-OOK modulation allowing for the clock recovery and a proper synchronisation between the transmitter and the receiver. In general, optical UWB communication systems using modulated/pulsed signals have the advantages of low power spectral density, null RF interference, immunity to multipath fading and high power efficiency, so suitable for short-range wireless links [17][18][19][20]. Based also on these characteristics, the proposed approach allows us to strongly reduce the system overall power consumption and the laser response time reaching data rates up to 128 Mbps with 800 ps laser pulses, a bit period of 7.8 ns and a power efficiency of 35.9 pJ/bit.…”

ARM-FPGA-based platform for reconfigurable wireless communication systems using partial reconfiguration

“…Adaptive channel encoding and code rate is another adaptive technique that has been proposed to select the best encoder or the code rate according to the channel status, as presented in [5][6][7].…”

Error control coding in wireless sensor networks

“…However, in order to generalize the results obtained in this work we adopted the general complexity metric defined in (5). Assuming an average number of 3 instructions/cycles to process a symbol, the required energy consumption to decode a bit, E bit dec , is then given by Figure 5 shows a comparison between the theoretical decoding complexity metric (symbols/bit) given by (5) and the practical decoding complexity (instructions cycles/bit) given by (6). It was assumed, without loss of generality, that the decoding of one symbol requires one instruction Fig.…”

“…Wireless Sensor Networks (WSN) [1] have received increasing attention in the last years, resulting in numerous published works that aim at providing solutions for problems as medium access control (MAC), network topology, routing protocols and error control strategies [2][3][4][5][6]. In general, WSN nodes are made of battery-supplied small devices with reduced processing capability and a radio frequency transceiver unity, both operating in a collaborative way [1].…”