Low-Complexity Lattice Reduction Demapper for Massive Order One-Dimensional Non-Uniform Constellations

Barrueco, Jon; Montalbán, Jon; Angueira, Pablo; Nour, Charbel Abdel; Douillard, Catherine

doi:10.1109/bmsb.2018.8436872

Cited by 6 publications

(4 citation statements)

References 15 publications

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“…Therefore, LUT-based approaches have gained popularity in many modern wireless systems [12], [13], [26]. For storing constellation points, LUT-based transmission can be feasible up to 256-ary constellations in real-time applications [27].…”

Section: Ieee Transactions On Wireless Communicationsmentioning

confidence: 99%

Adaptive Irregular Constellations for Full-Duplex Relaying With Residual Self-Interference

Ilter

Wichman

Hämäläinen

2021

IEEE Trans. Wireless Commun.

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We propose the use of adaptive optimized irregular constellation to enhance the performance of full duplex (FD) wireless radio systems which suffer from residual self-interference (RSI). Specifically, an error performance expression which takes into account the RSI level and signal-to-noise ratio is first derived for a single FD relay link. During the search for optimal constellation for a given parameter set, there are no predefined assumptions on symbol point locations. The optimization framework yields adaptive irregular constellations depending on RSI levels and power budget values. It is shown that the proposed adaptive transmission along with optimized irregular constellations achieves better error performance than the conventional M -QAM constellations and other M -ary improper Gaussian signaling (IGS) constellations.

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Section: Ieee Transactions On Wireless Communicationsmentioning

confidence: 99%

Adaptive Irregular Constellations for Full-Duplex Relaying With Residual Self-Interference

Ilter

Wichman

Hämäläinen

2021

IEEE Trans. Wireless Commun.

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“…In this part, we extend the new demapping algorithm to the 1D-1KNUC in NGB-W. Similarly, with 2D-NUCs, the main restriction of massive order 1D-NUCs is the number of computations required in the demapping stage [12]. Hence, our algorithm is also appropriate for 1D-1KNUC.…”

Section: B Extension To 1d-1knucmentioning

confidence: 99%

“…However, for massive order constellations (beyond 256 constellation points) the latency and demapping complexity involved in 2D-NUCs make their use unfeasible in the practical application. In this case, 1D-NUCs are the most appropriate solution [12]. Taking advantage of the capacity gain provided by NUCs, 2D-NUCs and massive order 1D-NUCs are adopted in NGB-W. As shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

International Journal of Electronics and Telecommunications

Wang¹,

Wang²,

Li³

et al. 2019

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This paper presents a novel low-complexity soft demapping algorithm for two-dimensional non-uniform spaced constellations (2D-NUCs) and massive order one-dimensional NUCs (1D-NUCs). NUCs have been implemented in a wide range of new broadcasting systems to approach the Shannon limit further, such as DVB-NGH, ATSC 3.0 and NGB-W. However, the soft demapping complexity is extreme due to the substantial distance calculations. In the proposed scheme, the demapping process is classified into four cases based on different quadrants. To deal with the complexity problem, four groups of reduced subsets in terms of the quadrant for each bit are separately calculated and stored in advance. Analysis and simulation prove that the proposed demapper only introduces a small penalty under 0.02dB with respect to Max-Log-MAP demapper, whereas a significant complexity reduction ranging from 68.75% to 88.54% is obtained.

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“…[ 14 ] proposed an algorithm by taking full advantage of the symmetric characteristics of symbol mapping. For massive-order non-uniform constellations, low-complexity demapping algorithms were proposed in [ 15 , 16 ] for one- and two-dimension constellations, respectively, and [ 17 ] proposed a universal low-complexity demapper for non-uniform constellations. For index modulation, a low-complexity LLR calculation algorithm was proposed in [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

Improving Log-Likelihood Ratio Estimation with Bi-Gaussian Approximation under Multiuser Interference Scenarios

Yang

2021

Entropy

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Accurate estimation of channel log-likelihood ratio (LLR) is crucial to the decoding of modern channel codes like turbo, low-density parity-check (LDPC), and polar codes. Under an additive white Gaussian noise (AWGN) channel, the calculation of LLR is relatively straightforward since the closed-form expression for the channel likelihood function can be perfectly known to the receiver. However, it would be much more complicated for heterogeneous networks where the global noise (i.e., noise plus interference) may be dominated by non-Gaussian interference with an unknown distribution. Although the LLR can still be calculated by approximating the distribution of global noise as Gaussian, it will cause performance loss due to the non-Gaussian nature of global noise. To address this problem, we propose to use bi-Gaussian (BG) distribution to approximate the unknown distribution of global noise, for which the two parameters of BG distribution can easily be estimated from the second and fourth moments of the overall received signals without any knowledge of interfering channel state information (CSI) or signaling format information. Simulation results indicate that the proposed BG approximation can effectively improve the word error rate (WER) performance. The gain of BG approximation over Gaussian approximation depends heavily on the interference structure. For the scenario of a single BSPK interferer with a 5 dB interference-to-noise ratio (INR), we observed a gain of about 0.6 dB. The improved LLR estimation can also accelerate the convergence of iterative decoding, thus involving a lower overall decoding complexity. In general, the overall decoding complexity can be reduced by 25 to 50%.

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Low-Complexity Lattice Reduction Demapper for Massive Order One-Dimensional Non-Uniform Constellations

Cited by 6 publications

References 15 publications

Adaptive Irregular Constellations for Full-Duplex Relaying With Residual Self-Interference

Adaptive Irregular Constellations for Full-Duplex Relaying With Residual Self-Interference

International Journal of Electronics and Telecommunications

Improving Log-Likelihood Ratio Estimation with Bi-Gaussian Approximation under Multiuser Interference Scenarios

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