Multiplex communications – Generalized orthogonal or special mathematical techniques – Particular set of orthogonal functions
Patent
1994-12-19
1997-02-11
Hsu, Alpus H.
Multiplex communications
Generalized orthogonal or special mathematical techniques
Particular set of orthogonal functions
370335, 375209, 375261, 375340, 379 59, 455 331, 455 541, H04B 7216, H04J 1302, H04L 2728
Patent
active
056028334
ABSTRACT:
Method and apparatus for generating orthogonally encoded communication signals for communication system subscribers using multiple orthogonal functions for each orthogonal communication channel. Digital data symbols for signal recipients are M-ary modulated using at least two n-length orthogonal modulation symbols, which are generally Walsh functions normally used within the communication system. These symbols are provided by a modulation symbol selector (124) typically from one or more code generators (126, 128), and the modulation is such that M equals a product of a total number of orthogonal functions and the number used to generate individual modulation symbols. Each group of log M encoded data symbols from data processing elements (100, 102) are mapped into one modulation symbol using the modulation symbol selection element (124) according to their binary values. In some embodiments, a fast Hadamard transformer is used for symbol mapping. The resulting communication signals are demodulated by correlating them with the preselected number of orthogonal functions, in parallel, and demodulating the results into M energy values representing each orthogonal modulation symbol. The energy values are mapped into energy metric data using a dual maximum metric generation process. The correlation and demodulation can be accomplished using at least two sets of N correlators (142), N being the number of functions used, and applying correlated signals to one demodulator for each set of correlators (144). Each demodulator outputs M energy values representing each of the M mutually orthogonal modulation symbols, which are then combined into a single set of M energy values. In further configurations, coherent demodulators (172, 174) can be used to produce amplitude values for received signals which are then combined (178) with dual maximum metric results (170) to produce composite metric values for data symbols (178).
REFERENCES:
patent: 4866395 (1989-09-01), Hostetter
patent: 4888788 (1989-12-01), Teranishi et al.
patent: 4901307 (1990-02-01), Gilhousen et al.
patent: 5101501 (1992-03-01), Gilhousen et al.
patent: 5103459 (1992-04-01), Gilhousen et al.
patent: 5109390 (1992-04-01), Gilhousen et al.
patent: 5166951 (1992-11-01), Schilling
patent: 5204874 (1993-04-01), Falconer et al.
patent: 5228054 (1993-07-01), Rueth et al.
patent: 5228056 (1993-07-01), Schilling
patent: 5239560 (1993-08-01), Daniel
patent: 5267261 (1993-11-01), Blakeney et al.
patent: 5309474 (1994-05-01), Gilhousen et al.
patent: 5311176 (1994-05-01), Gurney
patent: 5414728 (1995-05-01), Zehavi
patent: 5416797 (1995-05-01), Gilhousen et al.
patent: 5442627 (1995-08-01), Viterbi et al.
patent: 5450453 (1995-09-01), Frank
Digital Communications with Space Applications, S. W. Golomb et al., Prentice Hall, Inc. 1964, pp. 45-64.
Gregory E. Bottomley, "Signature Sequence Selection in a CDMA System with Orthogonal Coding", IEEE Transactions on Vehicular Technology, vol. 42, No. 1, New York, Feb. 1993. pp. 62-68.
Tetsuo Kirimoto et al., "Orthogonal Periodic Sequences Derived from M-Sequences on GF (q)", IEEE Transactions on Information Theory, vol. 40, No. 2, New York, Mar. 1994, pp. 526-532.
Hsu Alpus H.
Miller Russell B.
Ogrod Gregory D.
Qualcomm Incorporated
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