Fast SC decoding overcomes the latency caused by the serial nature of the SC decoding by identifying new nodes in the upper levels of the SC decoding tree and implementing their fast parallel decoders. In this work, we first present a novel sequence repetition node corresponding to a particular class of bit sequences. Most existing special node types are special cases of the proposed sequence repetition node. Then, a fast parallel decoder is proposed for this class of node. To further speed up the decoding process of general nodes outside this class, a threshold-based hard-decision-aided scheme is introduced. The threshold value that guarantees a given error-correction performance in the proposed scheme is derived theoretically. Analysis and hardware implementation results on a polar code of length 1024 with code rates 1/4, 1/2, and 3/4 show that our proposed algorithm reduces the required clock cycles by up to 8%, and leads to a 10% improvement in the maximum operating frequency compared to state-of-the-art decoders without tangibly altering the error-correction performance. In addition, using the proposed threshold-based hard-decision-aided scheme, the decoding latency can be further reduced by 57% at Eb/N0= 5.0 dB.

This paper focuses on fast successive-cancellation (SC) decoding of polar codes. A threshold-based hard-decision-aided scheme is proposed to speed up the decoding process, especially when the communications channel has low noise. In addition, to eliminate the error-correction performance degradation caused by hard decisions, a backtracking strategy is introduced. Simulation results on a polar code of code length 1024 and rate 1/2 show that, with the help of the proposed scheme, the average decoding latency of existing fast SC decoding algorithms can be reduced by 53% at an Eb/N0 = 5.0 dB with negligible error-correction performance degradation.

This study proposes an enhanced list‐aided successive cancellation stack (ELSCS) decoding algorithm with adjustable decoding complexity. Also, a logarithmic likelihood ratio‐threshold based path extension scheme is designed to further reduce the memory consumption of stack decoding. Numerical simulation results show that without affecting the error correction performance, the proposed ELSCS decoding algorithm provides a flexible trade‐off between time complexity and computational complexity, while reducing storage space up to 70%. Based on the fact that most mobile devices operate in environments with stringent energy budget to support diverse applications, the proposed scheme is a promising candidate for meeting requirements of different applications while maintaining a low computational complexity and computing resource utilisation.

Staircase codes (SCCs) are typically decoded using iterative bounded-distance decoding (BDD) and hard decisions. In this paper, a novel decoding algorithm is proposed, which partially uses soft information from the channel. The proposed algorithm is based on marking certain number of highly reliable and highly unreliable bits. These marked bits are used to improve the miscorrection-detection capability of the SCC decoder and the error-correcting capability of BDD. For SCCs with 2-error-correcting Bose-Chaudhuri-Hocquenghem component codes, our algorithm improves upon standard SCC decoding by up to 0.30 dB at a bit-error rate (BER) of 10-7. The proposed algorithm is shown to achieve almost half of the gain achievable by a genie decoder with this structure. The increased complexity caused by bit marking and additional calls to the component BDD decoder is discussed as well. Our algorithm is also extended (with minor modifications) to product codes. The simulation results show that in this case, the algorithm offers gains of up to 0.5 dB at a BER of 10-7.

Communication at mmWave frequencies has been the focus in the recent years. In this paper, we discuss standardization efforts in 60 GHz short range communication and the progress therein. We compare the available standards in terms of network architecture, medium access control mechanisms, physical layer techniques and several other features. Comparative analysis indicates that IEEE 802.11ad is likely to lead the short-range indoor communication at 60 GHz. We bring to the fore resolved and unresolved issues pertaining to robust WLAN connectivity at 60 GHz. Further, we discuss the role of mmWave bands in 5G communication scenarios and highlight the further efforts required in terms of research and standardization.

An energy efficient and transparent platform for optical wireless networks is proposed based on a novel reversely modulated optical single sideband scheme (RM-OSSB). This scheme is based on a parallel Mach-Zehnder modulator (P-MZM). The bandwidth limitation from electrical and optical components is overcome by down-conversion without electrical mixer, data format compatibility, and dispersion-free. It makes such scheme suitable for a universal platform. Moreover, the modulation power efficiency (MPE) of RM-OSSB can be improved. A theoretical model of RM-OSSB is built up for performance analysis. Both numerical simulations and experimental results match well with our theoretical model. Based on RM-OSSB scheme, a 58GHz full duplex RoF system is experimentally demonstrated. The 2.9Gb/s on-off keying (OOK) signals carried by 58GHz mm-wave is successfully delivered over 50km SMF with negligible power penalty.