| PhD Seminar

Name of the Speaker: Ms. Kavi Priya M (EE19D024)
Guide: Prof. Giridhar K
Venue: ESB-244 (Seminar Hall)
Online meeting link: https://meet.google.com/bxj-koxo-wid
Date/Time: 24th February 2025 (Monday), 3:00 PM
Title: Collision-Free Balanced Frequency Hopping Sequences for FHMA Applications

Abstract :

When multiple Frequency Hopping (FH) systems co-habit in the same geographical area and hop into the same frequency spot, it can result in multiple access interference (MAI): Collision-Free Frequency Hopping Sequences (FHS) are essential to maintain the throughput of co-habiting FH multiple access (FHMA) communication systems. Orthogonal frequency hopping sequences (O-FHS) can be used to avoid such collisions. We propose a new Collision-Free Balanced Frequency Hopping Sequence (CFB-FHS) set, where O-FHS based on maximum length sequences(m-sequences) are employed for a synchronous FHMA system with multiple subsystems. Every sequence from the CFB-FHS set is orthogonal to each other, and each subsystem utilizes a different sequence from the set. The proposed algorithm: (a) generates significantly longer O-FHS, (b) ensures full-band hopping, (c) ensures uniform usage of all the available frequency spots, even while maintaining the pseudo-random nature of the hopping sequences. The Hamming correlation and related properties of the proposed sequence set are also analyzed. The length of this CFB-FHS can be chosen based on the application requirements, and once a length is selected, it remains fixed regardless of the number of users in the FHMA system.