3,697 research outputs found

    Fast-SSC-Flip Decoding of Polar Codes

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    Polar codes are widely considered as one of the most exciting recent discoveries in channel coding. For short to moderate block lengths, their error-correction performance under list decoding can outperform that of other modern error-correcting codes. However, high-speed list-based decoders with moderate complexity are challenging to implement. Successive-cancellation (SC)-flip decoding was shown to be capable of a competitive error-correction performance compared to that of list decoding with a small list size, at a fraction of the complexity, but suffers from a variable execution time and a higher worst-case latency. In this work, we show how to modify the state-of-the-art high-speed SC decoding algorithm to incorporate the SC-flip ideas. The algorithmic improvements are presented as well as average execution-time results tailored to a hardware implementation. The results show that the proposed fast-SSC-flip algorithm has a decoding speed close to an order of magnitude better than the previous works while retaining a comparable error-correction performance.Comment: 5 pages, 3 figures, appeared at IEEE Wireless Commun. and Netw. Conf. (WCNC) 201

    Ultra-Sparse Non-Binary LDPC Codes for Probabilistic Amplitude Shaping

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    This work shows how non-binary low-density parity-check codes over GF(2p2^p) can be combined with probabilistic amplitude shaping (PAS) (B\"ocherer, et al., 2015), which combines forward-error correction with non-uniform signaling for power-efficient communication. Ultra-sparse low-density parity-check codes over GF(64) and GF(256) gain 0.6 dB in power efficiency over state-of-the-art binary LDPC codes at a spectral efficiency of 1.5 bits per channel use and a blocklength of 576 bits. The simulation results are compared to finite length coding bounds and complemented by density evolution analysis.Comment: Accepted for Globecom 201

    A Novel Network NOMA Scheme for Downlink Coordinated Three-Point Systems

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    In this paper, we propose a network non-orthogonal multiple access (N-NOMA) technique for the downlink coordinated multipoint (CoMP) communication scenario of a cellular network, with randomly deployed users. In the considered N-NOMA scheme, superposition coding (SC) is employed to serve cell-edge users as well as users close to base stations (BSs) simultaneously, and distributed analog beamforming by the BSs to meet the cell-edge user's quality of service (QoS) requirements. The combination of SC and distributed analog beamforming significantly complicates the expressions for the signal-to-interference-plus-noise ratio (SINR) at the reveiver, which makes the performance analysis particularly challenging. However, by using rational approximations, insightful analytical results are obtained in order to characterize the outage performance of the considered N-NOMA scheme. Computer simulation results are provided to show the superior performance of the proposed scheme as well as to demonstrate the accuracy of the analytical results

    Polar Code: An Advanced Encoding And Decoding Architecture For Next Generation 5G Applications

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    Polar Codes become a new channel coding, which will be common to apply for next-generation wireless communication systems. Polar codes, introduced by Arikan, achieves the capacity of symmetric channels with “low encoding and decoding complexity” for a large class of underlying channels. Recently, polar code has become the most favorable error correcting code in the viewpoint of information theory due to its property of channel achieving capacity. Polar code achieves the capacity of the class of symmetric binary memory less channels. In this paper review of polar code, an advanced encoding and decoding architecture for next generation applications

    Indonesia 5G Channel Model Under Foliage Effect

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    Abstract The performance of communications is determined by the channel, therefore knowledge of channel model of a country is important. This paper proposes (i) the fifth telecommunication generation (5G) Indonesia channel model and (ii) a framework to derive the channel model of any locations in Indonesia. We consider operating frequency of 3.3 GHz with bandwidth of 40 MHz with real-field parameters of several cities in Indonesia. We also present a theoretical outage performance evaluated for the proposed Indonesia 5G channel model validated by block error rate (BLER) performances of cyclic-prefix orthogonal frequency division multiplexing (CP-OFDM) numerology zero with 5G complex binary phase shift keying (C-BPSK) and Polar coding scheme. Sub-optimal Polar codes are used in this research, where better performances are expected in the future. We found that the Indonesia 5G channel model has 17 paths for the case of without foliage effect and has less than 15 paths for the case of with foliage effect. The results show that foliage attenuation causes performance degradations indicated by smaller number of paths and worse theoretical outage performances. The obtained outage performances from the proposed Indonesia 5G channel model in this paper are expected to be a reference for 5G implementations in Indonesia. Abstrak Kinerja sistem komunikasi ditentukan oleh kanal, sehingga pengetahuan model kanal suatu negara menjadi penting. Makalah ini mengusulkan (i) model kanal telekomunikasi generasi ke-lima (5G) Indonesia dan (ii) kerangka kerja untuk menghitung model kanal di lokasi lain di Indonesia. Model kanal dalam makalah ini diciptakan untuk bandwidth 40 MHz pada frekuensi 3,3 GHz dengan parameter riil lapangan. Makalah ini juga menampilkan teori outage performance yang diperoleh dari model kanal 5G Indonesia, kemudian memvalidasi teori outage performance tersebut menggunakan block error rate (BLER) pada cyclic-prefix orthogonal frequency division multiplexing (CP-OFDM) numerology zero dengan complex binary phase shift keying (C-BPSK) standard 5G dan Polar coding. Semua hasil numerik diperoleh dari simulasi komputer menggunakan parameter riil lapangan untuk alam Indonesia. Makalah ini menemukan bahwa kanal 5G Indonesia dapat dimodelkan power delay profile (PDP) dengan 17 path untuk kanal tanpa efek dedaunan dan kurang dari 15 path untuk kanal dengan dedaunan. Hasil tersebut menunjukkan bahwa redaman daun menyebabkan penurunan kinerja, yang ditandai dengan penurunan jumlah path dan memburuknya outage performance. Kurva outage performance yang diperoleh dari model kanal 5G Indonesia diharapkan menjadi referensi untuk implementasi sistem 5G di Indonesia dalam pengembangan 5G di Indonesia secara optimal, terutama untuk lokasi yang memiliki dedaunan lebat

    Comparison between Different Channel Coding Techniques for IEEE 802.11be within Factory Automation Scenarios

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    This paper presents improvements in the physical layer reliability of the IEEE 802.11be standard. Most wireless system proposals do not fulfill the stringent requirements of Factory Automation use cases. The harsh propagation features of industrial environments usually require time retransmission techniques to guarantee link reliability. At the same time, retransmissions compromise latency. IEEE 802.11be, the upcoming WLAN standard, is being considered for Factory Automation (FA) communications. 802.11be addresses specifically latency and reliability difficulties, typical in the previous 802.11 standards. This paper evaluates different channel coding techniques potentially applicable in IEEE 802.11be. The methods suggested here are the following: WLAN LDPC, WLAN Convolutional Codes (CC), New Radio (NR) Polar, and Long Term Evolution (LTE)-based Turbo Codes. The tests consider an IEEE 802.11be prototype under the Additive White Gaussian Noise (AWGN) channel and industrial channel models. The results suggest that the best performing codes in factory automation cases are the WLAN LDPCs and New Radio Polar Codes.This work was supported in part by the Basque Government under Grant IT1234-19, in part by the PREDOC under Grant PRE2019_099407, and in part by the Spanish Government through project PHANTOM (MCIU/AEI/FEDER, UE) under Grant RTI2018-099162-B-I00
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