System and method for maximizing video RF wireless transmission performance
View Patent ↗A system and method that will improve QoS (Quality of Service) of wireless video transmission systems. This is done by “in-fly” monitoring of BER by periodically transmitting “test images”, which images are known to the RF-receiver (Rx). BER can be automatically computed, within a related BIT (Built-in-Test) procedure that is also the subject of this invention. This allows predictions of a proper increasing, or decreasing of bandwidth OVH-level, in order to compensate for a BER-change. BER computation is facilitated by distinguishing video frames based on whether they depict new spatial events or related temporal events. Another subject of this invention is a motion-based pre-ATR method that is an introduction to common ATR, or pattern recognition methods. Yet another subject of this invention is a process of implanting error correcting bits into a payload, in the form of imperceptible watermarks. Still other aspects hereof, relate to such networks as: MAN, WAN, Tactical Internet, and others, to provide extra protection of headers, by implanting them into payloads, with a high level of Bit-Selective-Error Correction. Also included herein is a novel compression concept for still images which applies the spatial or meaningful frame technique to still imagery in a wavelet compression format.
1. In a wireless communication channel for transmitting compressed digital video data from transmitter to a receiver, a method of hardening a transmitted video data stream to avoid image interruptions despite changing channel conditions; the method comprising the steps of:
a) organizing streaming video frames into scenes defined by a single M-frame and a number of corresponding D-frames where M is meaningful and D is daughter and D-frames not significantly changed from their corresponding M-frame;
b) calculating the mean square error (MSE) of a video stream that is compressed, transmitted through said channel and reconstructed at the receiver, said calculation being carried out by highly parallel processors to compare pixel intensity variation between the M-frame and corresponding daughter frames of respective scenes;
c) deriving peak-signal-to-noise-ratio from the measured MSE to indicate quality of communication;
d) periodically transmitting known data through said communication channel to establish a statistical relation between peak-signal-to-noise-ratio and bit error rate for changing channel conditions; and
e) depending upon the outcome of steps c) and d), providing at least one of forward bit error correction and compression ratio modification to change hit error rate to avoid image interruptions.
2. The method recited in claim 1 wherein step e) comprises the step of increasing compression ratio to reduce bit error rate.
3. The method recited in claim 1 wherein step e) comprises the step of providing forward bit error correction as data embedded into the video data stream as an imperceptible watermark.
4. The method recited in claim 1 wherein step e) comprises the step of modifying the compression ratio until a maximum peak-signal-to-noise-ratio is obtained.
5. The method recited in claim 1 further comprising the step of compressing M-frame data differently from D-frame data.
6. The method recited in claim 1 further comprising the step of storing said video data prior to transmitting said data, and wherein said M-frame data is stored in a first format and said D-frame data is stored in a second format.
7. The method recited in claim 1 wherein said video data comprises payload data and overhead data and wherein step e) is carried out to provide greater hardening for said overhead data than for said payload data.