Source: https://patents.google.com/patent/US5999800
Timestamp: 2018-04-26 00:22:56
Document Index: 334986186

Matched Legal Cases: ['art 547', 'art 946', 'art 947', 'art 949', 'art 944', 'art 945', 'art 271', 'art 265', 'art 266', 'art 268', 'art 270', 'art 1709']

US5999800A - Design technique of an array antenna, and telecommunication system and method utilizing the array antenna - Google Patents
Design technique of an array antenna, and telecommunication system and method utilizing the array antenna Download PDF
US5999800A
US5999800A US08844364 US84436497A US5999800A US 5999800 A US5999800 A US 5999800A US 08844364 US08844364 US 08844364 US 84436497 A US84436497 A US 84436497A US 5999800 A US5999800 A US 5999800A
US08844364
R.sub.x (J+1)=f·R.sub.x (J)+x((J+1)T.sub.s)x.sup.H ((J+1)T.sub.s)(4)
a(θi)=[1e.sup.jπ sin θ.sbsp.i . . . e.sup.j(N-1)π sin θ.sbsp.i ].                                         (6)
w(k+1)=w(k)+σ(k)v(k)                                 (10)
R.sub.x (J)≈x(J)x.sup.H (J).                       (19)
λ(k)=|y(kT.sub.s)|.sup.2,
b(k)=v.sup.H (k)x(kT.sub.s)|.sup.2.               (20)
The terms in the procedure of the proposed technique that increase the complexity of the system are related to the matrix operations, i.e., Rx(k)·w(k) and R.sub.γ (k)·V(k).
γ(0)=x(0)·xH (0)·w(0)=x(0)·v*(0),
The adaptive gain computing part 547 generates the adaptive gain (σ) in accordance with the equation given below: ##EQU14## where F=C·D-B·E, G=C-y(t)2 E,
r=|y(t)|.sup.2 w-x(t)y*(t)               (26)
The procedure for obtaining the residue vector, as shown in FIG. 16 and equation (26), is the result of approximating the autocorrelation matrix with the instantaneous signal vector as: R=x(t)·xH (t).
As for the adaptive gain, letting A denote the output of the adding part 946, which is the result of the inner product of the signal vector and the search direction vector, letting B denote the output of the multiplying part 947, which is the result of the multiplication of the A and the final array output, letting C denote the output of the multiplying part 949, which is the square of the A, letting D denote the output of the adding part 944, which is the result of the inner product of the gain vector and the search direction vector, and letting E denote the output of the adding part 945, which is the result of the inner product of the search direction vector and itself, the adaptive gain (σ) is computed in accordance with the equation given below: ##EQU15## where F=C·Re[D]-B·Re[E], G=C-|y(t)|2 E,
H=Re [B]-|y(t)|2 ·Re [D],
and Re [·] denotes the real part of the complex-valued number "·"
B=y*·xH ·v,
w(J+1)=w(J)+σ(J)υ(J).
υ(J+1)=r(J+1)+βυ(J)
The adaptive gain computing part 271 generates the adaptive gain (σ) at each snapshot, in accordance with the equation given below: ##EQU18## where E, F and G are defined as: E=B·Re [C]-D·Re [A],
G=Re [D]-λ·Re [C],
with A, B, C and D being the output of the adding part 265, the output of the adding part 266, the output of the adding part 268, and the output of the adding part 270 respectively, and λ is the maximum eigenvalue, and Re [·] denotes the real part of the complex quantity "·".
The adaptive gain computing part 1709 described above generates the adaptive gain (σ) in accordance with the equation given below: ##EQU19## where E, F and G are defined as: E=B·Re [C]-D·Re [A],
and λ is the maximum eigenvalue and Re [·] denotes the real part of the complex quantity "·".
1. A method for designing a receiving array antenna consisting of plural antenna elements of predetermined arrangement and spacing between said antenna elements, wherein a final array output of said array antenna is obtained by a gain vector (w(k)), which is determined from an eigenvector corresponding to a maximum eigenvalue of an autocorrelation matrix of received signals, in accordance with an equation:
R(k)w(k)=λ.sub.MAX w(k),
where R(k) denotes the autocorrelation matrix of the received signals at k-- th snapshot with λMAX being the maximum eigenvalue of R(k).
2. A method according to claim 1, wherein said final array output is obtained by first multiplying each element of said gain vector to each signal induced at the corresponding antenna element and adding up the results of multiplications.
4. A method according to claim 1, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below: (in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at said present snapshot)
5. A method according to claim 1, wherein the eigenvector corresponding to the maximum eigenvalue is computed by the procedures of:
(a) determining the gain vector to synchronize a phase of each signal induced at every antenna element to a phase of a signal induced at a reference antenna element, during a first snapshot; and
(b) updating the gain vector of a last previous snapshot, in such a way that a Rayleigh quotient defined by the autocorrelation matrix and the gain vector is maximized at each snapshot, and a gain value to be multiplied to a signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during a second snapshot and on.
6. A method according to claim 5, wherein said reference antenna element is determined by an antenna element of which the phase of said signal is the latest of all said antenna elements in said array antenna at the present snapshot.
8. A method for designing a transmitting array antenna consisting of plural antenna elements of predetermined arrangement and spacing between said antenna elements, wherein a signal to be transmitted is phase delayed by multiplying the signal to be transmitted by each element of a gain vector (w(k)), which is determined from each element of an eigenvector corresponding to a maximum eigenvalue of an autocorrelation matrix of received signals, in accordance with an equation:
9. A method according to claim 8, wherein the signal to be transmitted is multiplied by a complex conjugate of each element of the gain vector (w(k)).
10. A method according to claim 8, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below: (in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at said present snapshot)
R.sub.x (J+1)=f·R.sub.x (J)+x((J+1)T.sub.s) x.sup.H ((J+1)T.sub.s)
11. A method according to claim 8, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:
(b) updating said gain vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix and said gain vector is maximized at each snapshot, and a gain value to be multiplied to signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during a second snapshot and on.
12. A method according to claim 11, wherein said reference antenna element is determined by an antenna element of which the phase of said signal is the fastest of all said antenna elements in said array antenna at the present snapshot.
14. A telecommunication system having an array antenna, comprising;
said array antenna composed of plural antenna elements, each of which is arranged by a predetermined geometry, that supplies signals induced at each antenna element to a corresponding port of a signal receiving means;
said signal receiving means that generates signal vector (x(t)) from the signals induced at each antenna element of said antenna array;
an inner product computing means for generating a final array output (y(t)) by computing an Euclidean inner product between two complex-valued vectors (y(t)=wH x(t)), wherein the signal vector (x(t)) produced from said signal receiving means and a gain vector (w) provided from a signal processing means: and
said signal processing means that computes the gain vector (w) from an eigenvector corresponding to a maximum eigenvalue of an autocorrelation matrix of received signals, in accordance with an equation:
Rw=λ.sub.MAX w,
where R denotes the autocorrelation matrix of the received signals with λMAX being the maximum eigenvalue of R for generating the final array output (y(t)) at said inner product computing means.
15. A telecommunication system having an array antenna according to claim 14, wherein said signal receiving means comprises:
a first group of multiplying means for multiplying the cosine terms ( cos(2 πfc t)) to each signal induced at every antenna element;
a second group of multiplying means for multiplying the sine terms ( sin(2 πfc t)) to each signal induced at every antenna element; and
a first and a second group of low pass filtering means which are connected to said first and second group of multiplying means.
16. A telecommunication system having an array antenna according to claim 14, wherein said signal receiving means comprises:
a second group of multiplying means for multiplying the sine terms ( sin(2 πfc t)) to each signal induced at every antenna element;
a first and a second group of low pass filtering means which are connected to said first and second group of multiplying means; and
a first and a second group of chip correlating means for performing cross-correlation of the outputs of said low pass filtering means with chip codes of in-phase (qj I (t)) and quadrature (qj Q (t)) components, respectively, where the subscript j is the index denoting the target subscriber.
17. A telecommunication system having an array antenna according to claim 16, wherein said signal receiving further comprises:
a plurality of IF (intermediate frequency) converting means for converting frequency bands of the signals induced at the antenna elements to intermediate frequency bands; and
a plurality of demodulating means which generates cosine and sine components of said IF signals.
18. A telecommunication system having an array antenna according to claim 14, wherein said signal receiving means comprises:
a plurality of IF (intermediate frequency) converting means for converting the frequency bands of the signals induced at the antenna elements to intermediate frequency bands;
a plurality of demodulating means which generates the cosine and sine components of said IF signals;
a first and a second group of chip correlating means for performing cross-correlation of the outputs of said demodulating means with the chip codes of in-phase (qj I (t)) and quadrature (qj Q (t)) components, respectively, where the subscript j is the index denoting the target subscriber.
19. A telecommunication system having an array antenna according to claim 14, wherein said signal processing means comprises:
a means for producing an adaptive gain (σ), by using said signal vector (x(t)), said search direction vector (υ), said final array output signal (y) of said telecommunication system at the last previous snapshot and the value of said gain vector (w) of the present snapshot; and
a means for updating said gain vector (w), by using said search direction vector (υ) and said adaptive gain (σ) at the present snapshot.
20. A telecommunication system having an array antenna according to claim 19, wherein said means for computing said residue vector comprises:
21. A telecommunication system having an array antenna according to claim 19, wherein said adaptive gain synthesizing means comprises:
22. A telecommunication system having an array antenna according to claim 21, wherein said adaptive gain computing means generates said adaptive gain (σ) in accordance with the equation given below: ##EQU20## where, F=C·Re[D]-B·Re[E], G=C-|y(t)|2 ·E,
H=Re [B]-|y(t)|2 ·Re [D], and
Re [·] denotes the real part of the complex valued number "·"
23. A telecommunication system having an array antenna according to claim 19, wherein said gain vector updating means comprises:
24. A telecommunication system having an array antenna according to claim 19, wherein said gain vector updating means further comprises a plurality of dividing means for dividing each output of said plurality of said adding means with the square root of N multiplied with the value of the output of said adding means connected to said reference antenna element, where N denotes the number of antenna elements in said array antenna.
25. A telecommunication system having an array antenna according to claim 19, wherein said scalar synthesizing means comprises:
26. A telecommunication system having an array antenna according to claim 19, wherein said search direction vector synthesizing means comprises:
27. A telecommunication system having an array antenna according to claim 14, wherein said signal processing means comprises:
28. A telecommunication system having an array antenna according to claim 27, wherein said residue vector synthesizing means comprises:
29. A telecommunication system having an array antenna according to claim 27, wherein said maximum eigenvalue synthesizing means for producing said maximum eigenvalue, by utilizing said autocorrelation matrix generated from said autocorrelation matrix generating means at each snapshot and said gain vector at the present snapshot, comprises:
30. A telecommunication system having an array antenna according to claim 27, wherein said adaptive gain synthesizing means comprises:
31. A telecommunication system having an array antenna according to claim 30, wherein said adaptive gain computing means generates said adaptive gain (σ) in accordance with the equation given below: ##EQU21## where E, F and G are defined as E=B·Re [C]-D·Re [A],
with A, B, C and D being the output of said second adding means, said third adding means, said fourth adding means and said fifth adding means, respectively,
and λ is said maximum eigenvalue, and Re [·] denotes the real part of the complex quantity "·".
32. A telecommunication system having an array antenna according to claim 14, wherein said signal processing means comprises:
a means for generating an adaptive gain (σ) at each snapshot, by utilizing said zeta vector (ζ), said search direction vector, said maximum eigenvalue and said gain vector at the present snapshot; and
33. A telecommunication system having an array antenna according to claim 32, wherein said residue vector synthesizing means comprises:
34. A telecommunication system having an array antenna according to claim 32, wherein said matrix operation approximation means comprises:
a plurality of fourth multiplying means for multiplying the outputs of said third multiplying means by said adaptive gain (σ) generated from said adaptive gain synthesizing means;
35. A telecommunication system having an array antenna according to claim 32, wherein said maximum eigenvalue synthesizing means comprises:
36. A telecommunication system having an array antenna according to claim 32, wherein said adaptive gain synthesizing means comprises:
37. A telecommunication system having an array antenna according to claim 36, wherein said adaptive gain synthesizing means generates said adaptive gain (σ) in accordance with the equation given below: ##EQU22## where E, F and G are defined as E=B·Re [C]-D·Re [A],
with A, B, C and D being the output of said first adding means, said second adding means, said third adding means and said fourth adding means, respectively,
and λ is the maximum eigenvalue, and Re [·] denotes the real part of the complex quantity "·".
38. A signal processing method for a telecommunication system having an array antenna generating a beam pattern with a complex-valued gain vector having its maximum gain along a direction of wanted signal keeping a gain along the other directions in relatively lower level, comprising the steps of:
(a) setting an initial gain vector;
(b) receiving signals with the gain vector at a present snapshot, or transmitting a target signal with the gain vector computed during a receiving mode or both;
(c) updating a snapshot index to continue next snapshot and receiving new signals for a new snapshot;
(d) determining whether an autocorrelation matrix is computed with an instantaneous signal vector only;
(e) setting a forgetting factor with 0, if so, otherwise, setting up the forgetting factor properly in between 0 and 1;
(f) updating the autocorrelation matrix by an equation (R(k)=fR(k-1)+x(k) xH (k), where f is the forgetting factor, k denotes a snapshot index, and a superscript H is a Hermitian operator);
(g) computing the gain vector in such a way that each element of the gain vector be as close as possible to corresponding element of an eigenvector corresponding to a maximum eigenvalue of an updated autocorrelation matrix; and
(h) going back to step (b) to repeat.
39. A signal processing method for a telecommunication system according to claim 38, further comprising the step of:
(i) performing a cross-correlation of received signals with a predetermined chip code of wanted signal after receiving new signals is comprised for applying a proposed method in a signal environment of spread spectrum.
40. A signal processing method for a telecommunication system according to claim 38, wherein the gain vector is determined by a vector that maximizes a power of a final array output at each snapshot.
42. A telecommunication system comprising:
an array antenna consisting of plural antenna elements of predetermined arrangement and spacing between said antenna elements;
a signal receiving apparatus wherein a reception of signals is performed by a weighted sum of a received signal vector (x(k)) with a complex gain vector (w(k)) maximizing a magnitude of a final array output, in accordance with an equation:
y(k)=wH (k) x(k) with a constraint of |w(k)|=1 at each snapshot; and
a signal transmitting apparatus wherein the gain vector is used during a transmitting mode.
43. A telecommunication system according to claim 42, wherein a constraint on the magnitude of the gain vector is an arbitrary positive real constant (i.e., |w(k)|=C, where C is a preset positive and real constant).
44. A signal processing method for an array antenna, comprising the steps of:
(a) setting up an initial gain vector (w(0)) based on signals received initially;
(b) receiving signals with the gain vector at a present snapshot, or transmitting a target signal with the gain vector computed during a receiving mode, or both;
(c) confirming whether the present snapshot is the last snapshot, if so, ending off all procedures;
(d) otherwise, setting a next snapshot, updating an autocorrelation matrix based on new signal vector received, and updating the gain vector with a value which approximates to an eigenvector corresponding to a maximum eigenvalue of autocorrelation matrix of received signals, in accordance with an equation:
where R denotes the autocorrelation matrix of received signals with λMAX being the maximum eigenvalue of R; and
(e) going back to said step (b) to repeat the procedures at each snapshot.
US08844364 1996-01-17 1997-04-18 Design technique of an array antenna, and telecommunication system and method utilizing the array antenna Expired - Lifetime US5999800A (en)
KR19960012172A KR100241503B1 (en) 1996-01-17 1996-04-18 Tranceiving signal processing method and apparatus for moile communication system using array antenna system
KR96-12172 1996-04-18
US5999800A true US5999800A (en) 1999-12-07
ID=19456292
US08844364 Expired - Lifetime US5999800A (en) 1996-01-17 1997-04-18 Design technique of an array antenna, and telecommunication system and method utilizing the array antenna
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