Use of orthonormal transformation for improving performance of digital transmission under heavily faded channels with doppler effects
The proposed invention teaches basic principles of “orthonormal transform” to be used to convert a set of discrete samples into a set of coefficient real samples that is contained in a finite field. The number of real values in each coefficient samples is finite and coded for transmission using digital modulation. It also teaches that handling of multi-path fading of Doppler effects implies that the Bit Error Rate (BER) performance as a function of Bit Energy/Noise (E b /N 0 ) is close to the performance of Additive White Gaussian Noise (AWGN) channel. The effect of impairments is minimized and only the effect of thermal noise (AWGN) is maintained. The inventive apparatus is simple and maintains constant end-to-end response time, sustainable effective data rate and bounded error performance which is conducive to specify a Quality of Service (QoS) which is useful for service provisioning.
1. An error correction method for use in a digital communications system comprising:
grouping incoming message bits from a message source into a plurality of groups, each group containing N bits, wherein said N bits range from 2-5;
creating discrete analog samples from each group of N bits;
transforming each of the analog samples into coefficient samples with a real 4-square ortho-normal matrix to create ortho-normal real value samples;
generating additional coefficient samples using d 1 =C 1 −C 2 +C 3 −C 4 and d 2 =C 1 +C 2 −C 3 −C 4 and transmitting the ortho-normal real value samples and the additional coefficient samples over the digital communications system;
receiving the ortho-normal samples and the additional coefficient samples at the receiver;
applying the additional coefficient samples with a set of error policies on said ortho-normal real value samples to correct an error in any of the ortho-normal real value samples;
processing the corrected ortho-normal real value samples by an invertible ortho-normal transform producing estimated discrete samples by transforming the corrected ortho-normal samples; and
decoding the estimated discrete samples to provide received message bits which match the incoming message bits.
2. An error correction method for use in a wireless network, comprising:
converting incoming information into N discrete samples, wherein said N range from 2-5;
transforming each of the discrete samples into N coefficient samples having finite set of real values in coefficient samples using
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interleaving the N coefficient samples;
encoding each said finite set of real value as a discrete constellation and transmitting the encoded information over the wireless network;
receiving the encoded information at the receiver;
providing phase and amplitude compensation, demodulation and de-interleaving for the encoded information at a receive side of the wireless network;
decoding the encoded information and error correcting the decoded information; and
mapping the decoded information to provide output information that matches the incoming information.
3. An error correction method for use in a digital communications system comprising:
grouping incoming message bits from a message source into a plurality of groups;
creating discrete analog samples from each group;
transforming each of the analog samples into coefficient samples with a real 4-square ortho-normal matrix to create ortho-normal samples;
generating additional coefficient samples using d 1 =C 1 −C 2 +C 3 −C 4 and d 2 =C 1 +C 2 −C 3 −C 4 and transmitting the ortho-normal samples and the additional coefficient samples over the digital communications system;
receiving the ortho-normal samples and the additional coefficient samples at the receiver;
applying the ortho-normal samples and the additional coefficient samples to an invertible ortho-normal transform to correct an error in any of the ortho-normal samples;
producing estimated discrete samples by transforming the corrected ortho-normal samples; and
decoding the estimated discrete samples to provide received message bits which match the incoming message bits.