IEEE 802.11 FHSS Receiver Design for Multihop Sensor Application

Published

May 1, 2002

Author(s)

K Ban, Hamid Gharavi

Abstract

This paper presents a receiver design for IEEE 802.11 FHSS (Frequency-Hopping Spread-Spectrum) wireless local area network systems. 802.11 FHSS systems support two basic data rates. 1 Mbps and 2 Mbps systems employ 2GFSK (Gaussian Frequency Shift Keying) and 4GFSK modulation, respectively. Noncoherent receivers are generally preferred for the 802.11 FHSS system. This is due to their practical advantages over coherent receivers such as implementation cost and inherent robustness against frequency and carrier phase offset. In this paper we first discuss popular receiver design techniques such as the limiter-discriminator integrator detector (LDD) and differential detector (DD). These techniques are normally considered for GMSK (Gaussian Minimum Shift Keying) receivers. Since GFSK modulations suffer from inter-symbol interference (ISI), even in the absence of channel distortions, designing a simple and yet efficient equalizer is expected to improve the receiver performance considerably. Thus, we have designed equalizers that are based on the Viterbi Algorithm (VA). We will show that such equalizers are very effective in improving the receiver performance, particularly in the case of 4GFSK modulation which is more sensitive to the inter-symbol interference due to its four level signaling.

Proceedings Title

2002 International Conference on Broadband Wireless Access Systems Conference Proceedings

Conference Dates

May 31, 2002

Conference Location

San Francisco, 1

Pub Type

Conferences

Citation

Ban, K. and Gharavi, H. (2002), IEEE 802.11 FHSS Receiver Design for Multihop Sensor Application, 2002 International Conference on Broadband Wireless Access Systems Conference Proceedings, San Francisco, 1 (Accessed May 8, 2024)