Transmitter diversity technique for wireless communications

Claim 2

The arrangement according to claim 1 where said first means replicates and negates an incoming symbol, wherein replicating and negating of an incoming signal may comprise forming a negative of an incoming symbol, forming a complex conjugate of an incoming symbol or forming a negative complex conjugate of an incoming symbol.

Claim 3

The arrangement according to claim 1 or 2 where said at least two distinct channels direct information to a single receiver antenna.

Claim 4

The arrangement according to one of claims 1 to 3 where each of said at least two distinct channels transmits a channel symbol for each incoming symbol encoded by said first means.

Claim 5

The arrangement according to one of claims 1 to 4 where said first means encodes incoming symbols in blocks of n symbols.

Claim 6

The arrangement according to claim 5 where, when n=2, the first means encodes the incoming block of symbols s 0 and s 1 into a sequence of symbols s 0 and - s 1 *, and into a sequence of symbols s 1 and s 0 *, where s 1 * is the complex conjugate of s i .

Claim 7

The arrangement according to one of claims 1 to 6 where said second means comprises a first antenna (11,31) and a second antenna (12,32), and where in response to a sequence { s 0 , s 1 , s 2 , s 3 , s 4 , s 5 ...} of incoming symbols said first means develops a sequence { s 0 , - s 1 *, s 2 , -s 3 *, s 4 , - s 5 *...} that is applied to said first antenna by said second means, and a sequence { s 1 , s 0 *, s 3 , s 2 *, s 5 , s 4 *...} that is applied to said second antenna by said second means where s i * is the complex conjugate of s i .

Claim 8

The arrangement according to claim 5 where said first means develops n · m channel symbols for each block of n incoming symbols, where m is the number of distinct channels.

Claim 9

The arrangement according to claim 8 where said n · m channel symbols are distributed to said m distinct channels.

Claim 10

The arrangement according to claim 9 where said transmitter employs K transmitter antennas to effect K distinct channels, and where said n · m channel symbols are distributed to said K antennas over L time intervals, where K=m and L=n, or K=n and L=m.

Claim 11

The arrangement according to claim 3 where said transmitter employs K transmitter antennas to effect K distinct channels and where said n · m channel symbols are distributed to K antennas over L frequencies, where K=m and L=n, or K=n and L=m.

Claim 12

The arrangement according to one of claims 1 to 11 further comprising a receiver having a single antenna that is adapted to receive and decode signals transmitted by said output stage.

Claim 13

The arrangement according to one of claims 1 to 11 further comprising a receiver having two receive antennas that is adapted to receive and decode signals transmitted by said output stage.

Claim 14

A transmitter comprising: first means for transmitting channel symbols over two different and distinct transmitter channel types, thereby providing transmitter-created diversity, where one of the channel types is space diversity, and the other of the transmitter channel types is frequency diversity or time diversity; for encoding incoming symbols in blocks of n symbols to form n · m channel symbols; and third means for distributing m groups of n channel symbols each to said first means.

Claim 15

The transmitter according to claim 14 where each on of said groups is applied to a first of said distinct transmitter channels.

Claim 16

The transmitter according to claim 14 or 15 where one of said distinct transmitter channels is effected with a plurality of transmitter antennas (11,12,31,32), providing space diversity, and another of said distinct transmitter channels is effected with a plurality of time intervals.

Claim 17

The transmitter according to claim 16 where the number of said transmitter antennas (11,12,31,32) is m and said m groups of channel symbols are distributed to said m transmitter antennas (11,12,31,32).

Claim 18

The transmitter according to one of claims 14 to 17 where n=2.

Claim 20

The method according to claim 19 where said encoding involves forming a complex conjugate of incoming symbols.

Claim 21

The method according to claim 19 or 20 where said encoding consists of replicating an incoming symbol, forming a complex conjugate of an incoming symbol, forming a negative of an incoming symbol or forming a negative complex conjugate of an incoming symbol.

Claim 23

The method according to claim 22 further comprising the step of developing said channel estimates responsive to said signals received by said antenna.

Claim 24

The method according to claim 23 wherein developing said channel estimates includes developing said channel estimates when said signals received by said antenna contain a known sequence.

Claim 26

The method according to claim 25 wherein said step of developing includes settling on symbols = s x , if d 2 ( , s x )≤ d 2 ( , s k ), where d 2 ( ,s x ) corresponds to ( s i -s x )( s i *- s x *).

Claim 27

The method according to claim 22 further comprising the step of estimating said channel estimates responsive to said sets of information symbols.

Claim 28

The method according to claim 22 further comprising the step of estimating and developing said channel estimates responsive to output signals from said step of developing.

Claim 29

The method according to claim 28 wherein said estimating and developing includes developing channel estimates h 0 and h 1 by evaluating the expressions where symbols s 0 and s i are output symbols of said step of developing maximum likelihood decisions, r 0 is a signal received at said antenna at a given time interval, r 1 is a signal received at said antenna at a next time interval, s i * is the complex conjugate of s i , and | s i | 2 is the magnitude, squared, of symbol s i .

Claim 30

A receiver comprising: a combiner (23, 26) responsive to non-noise signals received by an antenna (21) from space-diverse paths and to detected information symbols, for developing sets of information symbol estimates, where said combiner (23,26) develops said sets of information symbol estimates by combining said non-noise signals received by said antenna (21) with said detected information symbols with operations that involve multiplications, negations and conjugations; and a detector (24, 27, 42) responsive to said sets of information symbol estimates that employ maximum likelihood decisions regarding information symbols encoded into channel symbols and embedded in said non-noise signals received by said antenna (27), to develop thereby said detected information symbols, the receiver employing space diversity and either time or frequency diversity.

Claim 31

The receiver according to claim 30 where said signal received by said antenna (21) at a given time interval corresponds to r ( t ) = r 0 = h 0 s 0 + h 1 s 1 + n 0 , and at subsequent time intervals corresponds to r ( t + T ) = r 1 = - h 0 s 1 * + h 1 s 0 * + n 1 , r ( t +2 T ) = r 2 = h 0 s 2 + h 1 s 3 + n 2 , and r ( t +3 T ) = r 3 = - h 0 s 3 * + h 1 s 2 * + n 3 , where h 0 is a transfer function of a channel over which symbol s 0 is transmitted at said given time interval, h 1 is a transfer function of a channel over which a symbol s 1 is transmitted at said given time interval, the n terms are noise signals, and * appended to a signal designation represents the complex conjugate of the signal; and where said combiner (23,26) forms a set of information symbol estimates comprising symbols and by forming the signals where A = r 0 r 3 * - r 2 r 1 *.

Claim 32

The receiver according to claim 30 or 31 where said combiner (23, 26) develops a set of n information symbols from n · m received channel symbols, where m is the number of concurrent paths for which said channel estimator develops channel estimates.

Claim 33

A receiver comprising: a first channel estimator (53) responsive to a first antenna (51), for developing two space-diverse channel estimates; a second channel estimator (54) responsive to a second antenna (52), for developing two space-diverse channel estimates; a combiner (55) responsive to non-noise signals received by the first antenna (53) and the second antenna (52) and to channel estimates developed by said first and second channel estimators (53,54), for developing sets of information symbol estimates, where said combiner (55) develops said sets of information symbol estimates by combining said non-noise signals received by said antennas (51,52) with said channel estimates obtained from said first and said second channel estimators (53,54), with operations that involve multiplications, negations and conjugations; and a detector (56) responsive to said sets of information symbol estimates that develops maximum likelihood decisions regarding information symbols encoded into channel symbols and embedded in said non-noise signals received by said first and second antennas, the receiver employing space diversity and either time or frequency diversity.

Claim 34

A transmitted data signal for use by a wireless telecommunications system, wherein the signal comprises: blocks of symbols encoded using negation and complex conjugation of selected symbols within the blocks of signals; and wherein the encoded blocks of symbols are transmitted as at least two transmitted signals along at least two spatially diverse paths, and wherein the at least two transmitted signals include time diversity or frequency diversity.

Claim 35

The transmitted data signal according to claim 34 wherein the blocks of symbols include blocks of n symbols, and the encoded n blocks of symbols are transmitted as n transmitted signals along n spatially diverse paths.

Claim 36

The transmitted data signal according to claim 33 or 34 wherein the transmitted symbols have equal energy.

Claim 37

The transmitted data signal according to one of claims 33 to 35 wherein an incoming block of symbols s 0 and s 1 are encoded into a sequence of symbols so and - s 1 *, and into a sequence of symbols s 1 and s o *, where s i * is the complex conjugate of s i .