Tight bounds on communication complexity of symmetric XOR functions in one-way and SMP models

  • Authors:
  • Ming Lam Leung;Yang Li;Shengyu Zhang

  • Affiliations:
  • Department of Computer Science Engineering, The Institute of Theoretical Computer Science and Communications, The Chinese University of Hong Kong;Department of Computer Science Engineering, The Institute of Theoretical ComputerScience and Communications, The Chinese University of Hong Kong;Department of Computer Science Engineering, The Institute of Theoretical ComputerScience and Communications, The Chinese University of Hong Kong

  • Venue:
  • TAMC'11 Proceedings of the 8th annual conference on Theory and applications of models of computation
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

We study the communication complexity of symmetric XOR functions, namely functions f : {0, 1}n × {0, 1}n → {0, 1} that can be formulated as f(x, y) = D(|x ⊕ y|) for some predicate D : {0, 1, ..., n} → {0, 1}, where |x ⊕ y| is the Hamming weight of the bitwise XOR of x and y. We give a public-coin randomized protocol in the Simultaneous Message Passing (SMP) model, with the communication cost matching the known lower bound for the quantum and two-way model up to a logarithm factor. As a corollary, this closes a quadratic gap between the previous quantum lower bound and the randomized upper bound in the one-way model. This answers an open question raised in Shi and Zhang [SZ09], and disqualifies the problem from being a candidate to separate randomized and quantum one-way communication complexities.