Search

Polar codes, as the coding scheme for the control channel in fifth-generation mobile communication technology (5G), have attracted widespread attention since their proposal. As a mainstream decoding algorithm for polar codes, the successive cancellation list (SCL) decoder usually improves the error correction performance by increasing the list size, but this method suffers from the problems of high decoding complexity. To address this problem, this paper proposes a layered-search bit-flipping (LS-SCLF) decoding algorithm based on SCL decoding. Firstly, a new flip-bit metric is proposed, which derives a formula to approximate the probability of an error occurring in an information bit. This formula introduces a perturbation parameter to improve the calculation accuracy. Secondly, a compromise scheme for determining the perturbation parameter is proposed. The scheme uses Monte Carlo simulation to determine an optimized parameter for the precise positioning of the first erroneous decoded bit under different decoding conditions. Finally, a layered search strategy is adopted to sequentially search the erroneous decoded bits from the low order to high order, which can correct up to multiple bits at the same time. Simulation results show that the proposed algorithm achieves improved error correction performance with a slight increase in decoding complexity compared to the generalized SCL-Flip (GSCLF) decoding algorithm. This algorithm also achieves a good balance between the error correction performance and decoding complexity. [ABSTRACT FROM AUTHOR]

This algorithm considers the tap delay channel model in 5G protocol, and does not consider the influence of SNR on the log-likelihood ratio of the received sequence for the segmented cyclic redundancy bit adaptive (SCADSCL) polarization decoding algorithm. This paper proposes the post-processing (PSCAD-SCL) decoding algorithm for SCAD-SCL. The algorithm determines the number of constant and unreliable log-likelihood ratio used to improve the reliability setting through simulation, and flips and appropriately enlarges the unreliable log-likelihood ratio to improve the bit error rate performance. The simulation results show that the bit error rate of PSCAD-SCL is better than the original SCAD-SCL decoding algorithm in the signal-to-noise ratio of 1～3dB. When the bit error rate is 10-4, the performance of PSCAD-SCL algorithm is about 0.3dB higher than that of SCAD-SCL algorithm. The proposed algorithm can improve 5G transmission performance. [ABSTRACT FROM AUTHOR]

Non-orthogonal multiple access (NOMA) will play an imperative part in an advanced 5G radio arrangement, owing to its numerous benefits such as improved spectrum adeptness, fast data rate, truncated spectrum leakage, and, so on. So far, NOMA undergoes from peak to average power ratio (PAPR) problem, which shrinks the throughput of the scheme. In this article, we propose a hybrid method, centered on the combination of advanced Partial transmission sequence (PTS), Selective mapping (SLM), and bacteria foraging optimization (BFO), known as PTS-BFO and SLM-PTS. PTS and SLM are utilized at the sender side and divide the NOMA into several sub-blocks. An optimal phase factor is achieved by the BFA and combined with the NOMA sub-block, where a low peak power value is obtained. Further, we estimate the bit error rate (BER) and PAPR of BFA in the SLM and PTS technique. The simulation outputs reveal that the PTS-BFO outperforms the traditional peak power minimization approaches and moderates the complexity of the system. It is concluded that the proposed algorithm is not explored for the NOMA waveform. [ABSTRACT FROM AUTHOR]

Ultra-reliable and low-latency communications (URLLC) partakes a major role in 5 G networks for mission-critical applications. Sparse vector coding (SVC) appears as a strong candidate for future URLLC networks by enabling superior performance in terms of bit error rate (BER). SVC exploits the virtual digital domain (VDD) and compressed sensing (CS) algorithms to encode and decode its information through active symbol indices. In this paper, first, a clever encoding/decoding algorithm is proposed for the SVC scheme, which allows the use of all possible activation patterns (APs) resulting in increasing spectral efficiency. Second, a novel solution is proposed to convey additional information bits by further exploiting index modulation (IM) for the codebooks of the SVC scheme. Computer simulation results reveal that our low-complexity algorithm and novel IM solution provide not only a superior BER performance but also an increase in the number of bits conveyed by IM compared to the ordinary SVC approach. [ABSTRACT FROM AUTHOR]

This paper proposes an algorithm to design rate-adaptive irregular LDPC codes with improved Bit error rate (BER) performance. It focuses on achieving better BER results for higher order coding rates which are in high demand for 5G mobile communications. The algorithm generates a parity check matrix based on the message block size. The encoding complexity of the irregular LDPC code is comparatively reduced due to the proposed parity check matrix. Simulation results compare the BER performances of irregular LDPC codes for various code rates and modulation schemes with the Parity check matrix (PCM) generated by the proposed algorithm. The BER performance of improved irregular LDPC code is analyzed in a real-time scenario using Software Defined Radio platform as well. [ABSTRACT FROM AUTHOR]