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Auteurs principaux: Liu, Shuiyin, Sakzad, Amin
Format: Preprint
Publié: 2025
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Accès en ligne:https://arxiv.org/abs/2501.13380
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author Liu, Shuiyin
Sakzad, Amin
author_facet Liu, Shuiyin
Sakzad, Amin
contents This work addresses the joint optimization of power and bit allocation in precoded large-scale n x n MIMO systems with discrete input alphabets, specifically QAM constellations. We propose an adaptive QAM scheme that maintains a fixed gap to the Gaussian-input capacity for a given n. A key finding is that, under the proposed scheme, the mercury/waterfilling (MWF) solution reduces analytically to the classical water-filling (WF) policy. Furthermore, the adaptive QAM configuration can be precomputed under the large-system assumption, enabling the replacement of full SVD with truncated SVD and yielding substantial computational savings. To support practical deployment, we develop a bit-allocation algorithm that meets a target transmission data rate while minimizing the overall decoding error rate and preserving computational complexity at O(n log n). Simulation results confirm that the proposed truncated SVD precoding, paired with the joint power and bit allocation, achieves superior decoding performance relative to conventional approaches, while operating at significantly lower complexity.
format Preprint
id arxiv_https___arxiv_org_abs_2501_13380
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Joint Power and Bit Allocation for Precoded Massive MIMO Channels
Liu, Shuiyin
Sakzad, Amin
Information Theory
This work addresses the joint optimization of power and bit allocation in precoded large-scale n x n MIMO systems with discrete input alphabets, specifically QAM constellations. We propose an adaptive QAM scheme that maintains a fixed gap to the Gaussian-input capacity for a given n. A key finding is that, under the proposed scheme, the mercury/waterfilling (MWF) solution reduces analytically to the classical water-filling (WF) policy. Furthermore, the adaptive QAM configuration can be precomputed under the large-system assumption, enabling the replacement of full SVD with truncated SVD and yielding substantial computational savings. To support practical deployment, we develop a bit-allocation algorithm that meets a target transmission data rate while minimizing the overall decoding error rate and preserving computational complexity at O(n log n). Simulation results confirm that the proposed truncated SVD precoding, paired with the joint power and bit allocation, achieves superior decoding performance relative to conventional approaches, while operating at significantly lower complexity.
title Joint Power and Bit Allocation for Precoded Massive MIMO Channels
topic Information Theory
url https://arxiv.org/abs/2501.13380