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US5832044A
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Transmitter antenna diversity and fading-resistant modulation for wireless communication systems
Assignee: Individual
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Filing: 1996-09-27
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Granted: 1998-11-03
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Expires: 2016-09-27
Abstract
Abstract The present invention provides a bandwidth-efficient fading-resistant transmission scheme where a base station implements transmitter diversity using L antennas or L carrier frequencies or L time slots, regardless of the use of frame oriented power control. When the antennas or carriers are spaced sufficiently far apart, or when a different power is used for each power control frame, the transmission from each antenna or carrier or time frame undergoes independent fading. These transmissions are coordinated to mitigate the effects of Rayleigh fading and the mobile receiver can recover the entire L-dimensional transmitted vector as long as the signal energy of at least one coordinate is large enough. L-dimensional fading-resistant signal constellations are generated by maximizing a figure of merit for the Rayleigh fading channel. This scheme offers a significant performance improvement over a conventional single-antenna or single-carrier narrowband BPSK scheme when coding is ineffective due to slow fading. When there is background white Gaussian noise, the fading-resistant scheme has a significant energy savings advantage over an uncoded BPSK scheme, for a given bit error rate. In the forward link of a cellular network, where cochannel interference is the dominant source of noise, the fading-resistant scheme results in a significant capacity increase over uncoded BPSK, for a given bit error rate. Both coherent and differentially coherent systems are disclosed.
Inventors
- 👤 Elvino S. Sousa
- 👤 Victor M. DaSilva
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:36
CPC Classifications
H; H04; H04W; H04W52/00; H04W52/04; H04W52/38; H04W52/42; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/06; H04L; H04L1/00; H04L1/02; H04L1/06; H04L1/0618; H04L27/00; H04L27/18; H04L27/22; H04L27/227; H04L27/233; H04L27/2331; H04L27/32; H04L27/34; H04L27/3405
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
101 words
A method of fading-resistant modulation for wireless communication systems using transmitter antenna diversity, comprising: a) selectively constructing an L-dimensional signaling constellation comprising Q points, wherein each of said Q points represents a vector in an L-dimensional vector space, the vector space comprising L orthogonal coordinate axes and each vector having L vector components, and wherein any two of said vectors differ in a plurality of corresponding vector components; and b) transmitting each of said L components of a given constellation point of said signalling constellation over one of either L different antennas, L different carrier frequencies and L different time slots.
Claim 2
Independent Claim
101 words
A method of fading-resistant modulation for wireless communication systems using transmitter antenna diversity, comprising: a) selectively constructing an L-dimensional signaling constellation comprising Q points, wherein each of said Q points represents a vector in an L-dimensional vector space, the vector space comprising L orthogonal coordinate axes and each vector having L vector components, and wherein any two of said vectors differ in a plurality of corresponding vector components; and b) transmitting each of said L components of a given constellation point of said signalling constellation over one of either L different antennas, L different carrier frequencies and L different time slots.
Claim 3
Dependent Claim
38 words
The method according to claim 1 wherein the signaling constellation is constructed by applying a transformation to an L-dimensional hypercube, and wherein said transformation is effective to preserve the Euclidean distances between the points of the signaling constellation.
Claim 4
Dependent Claim
32 words
The method according to claim 1 wherein in the signaling constellation substantially none of the points of the constellation are superimposed by collapsing said constellation parallel to any of said coordinate axes.
Claim 5
Dependent Claim
119 words
The method according to claim 1 wherein said signaling constellation is the Kerpez constellation comprising Q=M L constellation points (m 1 ,m 2 , . . . ,m L ) wherein M is an integer substantially equal to the number of bits transmitted per dimension, wherein specification of i 1 ε{1,2, . . . ,M L } uniquely defines an L-dimensional alphabet symbol, and wherein said L-dimensional alphabet symbol has j th coordinate given by m j =-2i j +M L +1, i j ε{1,2, . . . ,M L } where i j , 2≦j≦L, is related to i 1 by i l !i j = (i 1 -1)M L-j+1 !modM L-j+1 +1 i 1 /m j-1 !.
Claim 6
Dependent Claim
29 words
The method according to claim 1 wherein the signals corresponding to the components of the signaling constellation transmitted in each antenna, carrier frequency or time slot are differentially encoded.
Claim 7
Dependent Claim
29 words
The method according to claim 4 wherein the signals corresponding to the components of the signaling constellation transmitted in each antenna, carrier frequency or time slot are differentially encoded.
Claim 8
Dependent Claim
40 words
The method according to claim 1 wherein said signals are transmitted over L carrier frequencies using at least one antenna, said carrier frequencies having an effective frequency spacing so that fading is substantially independent over said L different carrier frequencies.
Claim 9
Dependent Claim
32 words
The method according to claim 1 wherein said signals are transmitted over L different time slots wherein a coordinate of a point of said signaling constellation is transmitted during each time slot.
Claim 10
Dependent Claim
42 words
The method according to claim 8 wherein the time slots correspond to different power control groups, and wherein the transmitted power is adjusted once per power control group, and wherein independent fading in the different time slots correspond to power control errors.
Claim 11
Dependent Claim
25 words
The method according to claim 1 wherein said signaling constellation is used to provide symbols for a trellis code or convolutional code, or block code.
Claim 12
Dependent Claim
26 words
The method according to claim 1 wherein a sequence of transmitted components in each antenna, frequency, or time slot, constitutes a PAM, BPSK, or QPSK signal.
Claim 13
Dependent Claim
26 words
The method according to claim 1 wherein a sequence of transmitted components in each antenna, frequency, or time slot, constitute a spread spectrum or CDMA signal.
Claim 14
Dependent Claim
21 words
The method according to claim 1 wherein the L-components transmitted over the L-different antennas represent a set of L orthogonal waveforms.
Claim 15
Dependent Claim
19 words
The method according to claim 1 wherein any two of said vectors differ in substantially all corresponding vector components.
Claim 16
Dependent Claim
23 words
The method according to claim 9 wherein the wireless communication system is a cellular communication system including at least forward and reverse links.
Claim 17
Independent Claim
95 words
A method of fading-resistant modulation for wireless communication systems, comprising: a) selectively constructing an L-dimensional signaling constellation comprising 2 L constellation points wherein each of said 2 L constellation points represents an L-component vector in an L-dimensional vector space, said L-dimensional vector space including L orthogonal coordinate axis, and wherein any two of said vectors differ in a plurality of their components; and b) transmitting each of said L components of a given constellation point of said signalling constellation over one of either L different antennas, L different carrier frequencies and L different time slots.
Claim 18
Independent Claim
95 words
A method of fading-resistant modulation for wireless communication systems, comprising: a) selectively constructing an L-dimensional signaling constellation comprising 2 L constellation points wherein each of said 2 L constellation points represents an L-component vector in an L-dimensional vector space, said L-dimensional vector space including L orthogonal coordinate axis, and wherein any two of said vectors differ in a plurality of their components; and b) transmitting each of said L components of a given constellation point of said signalling constellation over one of either L different antennas, L different carrier frequencies and L different time slots.
Claim 19
Dependent Claim
37 words
The method according to claim 16 wherein the signaling constellation is constructed by applying an orthogonal transformation to an L-dimensional hypercube to form a transformed hypercube with said constellation points being the vertices of said transformed hypercube.
Claim 20
Dependent Claim
44 words
The method according to claim 17 wherein the orthogonal transformation of the hypercube comprises representing said hypercube constellation as a matrix with rows of said matrix being equal to the vertices of the hypercube, and multiplying said matrix by an effective L×L orthogonal matrix.
Claim 21
Dependent Claim
36 words
The method according to claim 16 wherein said wireless communication system is a cellular system having a base station and mobile terminals, forward and reverse links, and wherein said signals are transmitted from said base station.
Claim 22
Dependent Claim
19 words
The method according to claim 17 wherein L=2 and said orthogonal transformation is a rotation of about 31.7 degrees.
Claim 23
Dependent Claim
30 words
The method according to claim 16 wherein the signals corresponding to the components of the signaling constellation transmitted over each carrier frequency, each antenna or time slot are differentially encoded.
Claim 24
Dependent Claim
26 words
The method according to claim 16 wherein a sequence of transmitted components in each antenna, frequency, or time slot, constitutes a PAM, BPSK, or QPSK signal.
Claim 25
Dependent Claim
26 words
The method according to claim 16 wherein a sequence of transmitted components in each antenna, frequency, or time slot, constitute a spread spectrum or CDMA signal.
Claim 26
Dependent Claim
21 words
The method according to claim 16 wherein the L-components transmitted over the L-different antennas represent a set of L orthogonal waveforms.
Claim 27
Dependent Claim
19 words
The method according to claim 16 wherein any two of said vectors differ in substantially all corresponding vector components.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-11-02 | 2002-05-04 | 2002-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-02 | 2006-05-04 | 2006-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-02 | 2010-05-04 | 2010-11-03 | $7700.00 | Window Closed / Lapsed |