Enhanced Frequency Hopping for Deployments with Limited Spectrum

As the wireless industry migrates to 3G and beyond, service providers are faced with supporting multiple technologies in limited spectrum. Limited spectrum deployments have an impact on the performance of frequency hopped networks where users are more likely to hop to the same frequencies multiple times over a short interval. Hopping to the same frequency within the interleaving depth of a speech frame results in decreased fading diversity and increased error rates for users with low mobility or alternatively large coherence times. In this paper, a constrained frequency hopping algorithm is proposed to improve fading diversity. Simulations were conducted for tight reuse (i.e., 1/3, 1/1) GSM deployments and were shown to achieve considerable gains.