[ii] Patent Number: 5,757,767  Date of Patent: May 26, 1998
Ohira.Takao et al., "Picture Quality of HadamardTransform ... "Appl. of Walsh Functions. 1973 Proa. Naval Res. Lab. pp. 127-129.
Digital Communications with Space Applications, S.W. Golomb et al.. Prentice Hall, Inc. 1964. pp. 45-64.
Primary Examiner—Douglas W. Olms
Assistant Examiner—Matthew C. Phillips
Attorney, Agent, or Firm—Russell B. Miller; Gregory D.
A more efficient and less complex structure and method for combining multiple user channels onto a single carrier frequency in spread spectrum communication systems. A single transformation element, such as a fast Hadamard Transformation processor, is used to orthogonally encode and combine a series of subscriber digital data signals in parallel. Portions of the orthogonally encoded and combined data signals are then selected over preselected time intervals to generate a single encoded data signal which is subsequently PN spread, subjected to analog signal processing, and transmitted to system subscribers. This is typically effected by summing digital values in an array of data signal combiners. An exemplary data transformation device uses at least one of a preselected set of orthogonal functions as a controlling pattern for interconnection of the combining elements. Each of the combining elements receives at least two input signals, either data or previously combined data, and produces a combined encoded signal output. The order of combination maps the input data signals into an orthogonal combined signal. Portions of the combined data signals are then selected and transferred in order as a serialized data stream for subsequent spreading and transmission as a communication signal.
19 Claims, 9 Drawing Sheets