Xiaxin Li

2papers

2 Papers

0.0ITApr 12
Support Recovery in One-bit Compressed Sensing with Near-Optimal Measurements and Sublinear Time

Xiaxin Li, Arya Mazumdar

One-bit compressed sensing (1bCS) addresses the recovery of sparse signals from highly quantized measurements, retaining only the sign of each linear measurement. In the support recovery setting, the goal is to identify $\text{supp}(x)$, the nonzero coordinates of an unknown signal $x \in \mathbb{R}^n$ from $y = \text{sign}(Ax)$, where $A \in \mathbb{R}^{m \times n}$ and $|\text{supp}(x)| \le k \ll n$. Existing methods minimize the number of measurements but often incur $Ω(n)$ decoding complexity, limiting large-scale applicability. We propose new 1bCS schemes that achieve sublinear decoding complexity while maintaining near-optimal measurement bounds. For universal support recovery, our framework provides: (i) exact recovery with $m = O(k^2 \log(n/k) \log n)$ measurements and decoding complexity $D=O(km)$, and (ii) $ε$-approximate recovery with $m = O(k ε^{-1} \log(n/k) \log n)$ and $D=O(ε^{-1} m)$. For probabilistic exact recovery, we design a scheme with $m = O\big(k \frac{\log k}{\log\log k} \log n\big)$ and $D=O(m)$, achieving vanishing error probability. Our approach leverages ideas from group testing to bridge classical sparse recovery techniques with modern algorithmic efficiency considerations, highlighting a new trade-off between compression efficiency and computational complexity.

1.1ITApr 20
The Noisy Quantitative Group Testing Problem

Tenghao Li, Neha Sangwan, Xiaxin Li et al.

In this paper, we study the problem of quantitative group testing (QGT) and analyze the performance of three models: the noiseless model, the additive Gaussian noise model, and the noisy Z-channel model. For each model, we analyze two algorithmic approaches: a linear estimator based on correlation scores, and a least squares estimator (LSE). We derive upper bounds on the number of tests required for exact recovery with vanishing error probability, and complement these results with information-theoretic lower bounds. In the additive Gaussian noise setting, our lower and upper bounds match in order.