Noise-Tolerant Codebooks for Semi-Quantitative Group Testing: Application to Spatial Genomics
Kok Hao Chen, Duc Tu Dao, Han Mao Kiah, Van Long Phuoc Pham, Eitan Yaakobi
TL;DR
This work develops a formal framework for noise-tolerant codebooks in semi-quantitative group testing, motivated by spatial genomics. It introduces ${\lambda-{\sf ADD}}$-codes that interpolate ${\sf OR}$, ${\sf XOR}$, and ${\sf ADD}$ codes using the ${\boxplus}_{\boldsymbol{\lambda}}$ operation, and provides explicit constructions and bounds in two regimes: constant distance $d$ (where XOR-based constructions yield rates approaching $\tfrac{1}{2}$ for small defectives, e.g., $s=2$) and distance $d=\delta n$ (where computable Gilbert-Varshamov-type bounds apply). The XOR codes receive sharp asymptotic rate characterizations, while the ${\lambda-ADD}$ family enables GV-type lower bounds, with comparisons showing the GV bounds often outperform indirect constructions, and XOR-based methods excel at small $\delta$. Upper bounds for ADD-codes are established via ternary-code embeddings, indicating a fundamental gap between achievable and provable limits and guiding practical code design for spatial-genomics-like settings. Overall, the results yield practical, near-optimal codebooks for robust semi-quantitative testing with potential impact on efficient spatial genomics workflows.
Abstract
Motivated by applications in spatial genomics, we revisit group testing (Dorfman~1943) and propose the class of $λ$-{\sf ADD}-codes, studying such codes with certain distance $d$ and codelength $n$. When $d$ is constant, we provide explicit code constructions with rates close to $1/2$. When $d$ is proportional to $n$, we provide a GV-type lower bound whose rates are efficiently computable. Upper bounds for such codes are also studied.
