IEEE 802.11 FHSS receiver design for cluster‐based multihop video communications

Abstract

AbstractRecently, we proposed an ad hoc, cluster‐based, multihop network architecture for video communications using IEEE 802.11 FHSS (Frequency Hopping Spread Spectrum) wireless LAN (WLAN) technology with 2GFSK (2‐level Gaussian Frequency Shift Keying) modulation capable of 1 Mb s−1 transmission. To increase the transmission rate to 2 Mb s−1 for higher‐quality video communications, we evaluated the performance of the IEEE 802.11 FHSS system when a 4GFSK modulation option is selected. Since the 2 Mb s−1 system utilizing 4GFSK modulation is not very efficient in terms of Radio Frequency (RF) range, to improve its performance for multihop applications a combination of diversity and noncoherent Viterbi equalizer are considered. For video transmission, we employed a bitstream‐splitting technique together with a packet‐based error‐protection strategy to combat packet drops under multipath fading conditions. The real‐time transport protocol (RTP), user datagram protocol (UDP), and Internet protocol (IP) are used for video streaming. This includes an RTP packetization scheme to control the packet size and to improve the error‐resilient decoding of the partitioned video signal. The paper includes the simulation results showing the effects of the receiver design and diversity on the quality of the received video signals. Copyright © 2002 John Wiley & Sons, Ltd.