Feasibility study and simulation of a wireless video graphics array system

This thesis investigates the feasibility of a wireless computer-video system which would be capable of transmitting Video Graphics Array (VGA) standard video signals over a distance of 20m (a large room's long dimension). Such a system should be designed to have practically equivalent video performance to a wired computer monitor (in most situations), while meeting practical design constraints such as limited bandwidth and power usage and low-cost.;In this thesis, video compression techniques are studied and a compression scheme is designed in order to achieve high compression ratios while maintaining the video's fidelity. High video quality is very important in most computing situations where the average user spends most of their time viewing text or other static screen displays that require true-color lossless video. When reading black text on a white screen, it would be very irritating to have frequent color errors either in the text or the page. For this reason, it is important to implement a lossless compression scheme during static frame sequences. During motion-video frame sequences, video color quality and crispness can be sacrificed in order to increase the video compression ratio, as lossless frame-differencing alone creates too high of a data payload.;An OFDM system is simulated in Matlab's Simulink at the base-band level. The model template was made by Martin Clark of Mathworks and submitted to Matlab Central's File Exchange. The model is based on the 802.11 a WLAN standard, and so it was modified to accommodate the needs of the wireless video graphics array system (WVGA).;Results show that during static frame sequences, the system's output video quality matches that of the input video (original VGA signal). Special care is taken in order to reduce errors in the most significant color bits during this type of video situation. However, during full screen motion-video frame sequences, lossy compression techniques are used to reduce the bit rate to an acceptable level while maintaining acceptable video quality for the amount of video motion.;The VGA standard includes a wide range of resolutions and refresh rates [1]. However, due to limited unlicensed bandwidth and the typical operating environment of such a device, the range of resolutions and refresh rates possible in a wireless VGA system will be limited no matter what type of video compression is used. A system is designed that can support full screen motion-video at the 1024x768 resolution. The compression scheme will be able to maintain video fidelity during static-screen sequences while decreasing the video quality during motion video sequences. The motion of the video decreases the distracting effect of the errors.