EP0896441A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
CDMA receiver with antenna array
Assignee: NEC Corp
•
Filing: 1998-08-05
•
Granted: —
•
Expires: 2018-08-05
Abstract
Abstract In a CDMA receiver, signals from a number of correlatively spaced apart antennas are respectively multiplied by weight coefficients and summed together to produce a weighted sum signal, which is separated into multipath components of a transmitted signal. The multipath components are despread with a chip sequence, producing despread signals at symbol intervals. Demodulators estimate channel responses of propagation paths from the despread signals and multiply the despread signals by the estimated channel responses to produce demodulated signals, which are summed and a threshold decision is made on the sum of the demodulated signals to produce a decision output. Error detection circuitry multiplies the decision output by the estimated channel responses to produce a number of multiplied decision outputs, and detects differences between the multiplied decision outputs and the despread signals to produce a number of error signals, which are combined together. Weight control circuitry is responsive to the combined error signals for updating the weight coefficients.
Inventors
- 👤 Yasushi Maruta
- 👤 Shousei Yoshida
- 👤 Akihisa Ushirokawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 22:56
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0837; H04B7/0842; H04B7/0848; H04B7/0851
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
154 words
A code division multiple access communication receiver
comprising: a plurality of antennas spaced a correlation distance apart from each
other; multiply-and-add circuitry for respectively weighting signals from
said antennas with weight coefficients and summing the weighted signals to
produce a weighted sum signal; separation circuitry for separating the weighted sum signal into
multipath components which respectively correspond to propagation paths
of a signal transmitted from a user station; a plurality of despreaders for respectively despreading the separated
multipath components with a chip sequence assigned to the user station to
produce a plurality of despread signals at symbol intervals; error detection circuitry for detecting a plurality of errors between a
symbol output and the despread signals and combining said plurality of
errors to produce a combined error signal; and weight control circuitry for producing said weight coefficients from
the signals detected by said antennas and updating the weight coefficients
according to the combined error signal.
Claim 2
Dependent Claim
127 words
A code division multiple access communication receiver as
claimed in claim 1, further comprising: a plurality of demodulators for estimating channel responses of said
propagation paths from the despread signals, and multiplying the despread
signals by the estimated channel responses to produce a plurality of
demodulated signals; an adder for summing said plurality of demodulated signals; and a decision circuit for making a threshold decision on the summed
demodulated signals to produce a decision output as said symbol output, wherein said error detection circuitry is arranged to: multiply the decision output by the estimated channel responses to
produce a plurality of multiplied decision outputs, and detect a plurality of differences between said plurality of multiplied
decision outputs and the despread signals to produce said plurality of errors.
Claim 3
Dependent Claim
29 words
A code division multiple access communication receiver as
claimed in claim 2, wherein said error detection circuitry is arranged to
multiply said plurality of differences by the chip sequence.
Claim 4
Dependent Claim
40 words
A code division multiple access communication receiver as
claimed in claim 1, wherein said error detection circuitry is arranged to
multiply said plurality of errors by the chip sequence and combine the
multiplied errors to produce said combined error signal.
Claim 5
Dependent Claim
22 words
A code division multiple access communication receiver as
claimed in any preceding claim, wherein said symbol output is a
known symbol value.
Claim 6
Dependent Claim
32 words
A code division multiple access communication receiver as
claimed in an preceding claim, wherein said weight control circuitry
is arranged to update said weight coeffecients according to minimum
mean square error algorithm.
Claim 7
Dependent Claim
174 words
A code division multiple access communication receiver
comprising: a plurality of antennas spaced a correlation distance apart from each
other; a plurality of despreaders for respectively despreading signals
detected by the antennas with a chip sequence assigned to a user station to
produce a plurality of despread signals at chip intervals; multiply-and-add circuitry for respectively weighting the despread
signals by weight coefficients, separating each of the weighted despread
signals into a plurality of multipath components which respectively
correspond to propagation paths of a signal transmitted from the user
station and summing the separated multipath components to produce a
plurality of weighted sum signals each representative of the sum of the
multipath components of same arrival time; error detection circuitry for detecting a plurality of errors between a
symbol output and said plurality of weighted sum signals, and combining
said plurality of errors to produce a combined error signal; and weight control circuitry for producing said weight coefficients from
said plurality of despread signals and updating the weight coefficients
according to the combined error signal.
Claim 8
Dependent Claim
130 words
A code division multiple access communication receiver as
claimed in claim 7, further comprising: a plurality of demodulators for estimating channel responses of said
propagation paths from said weighted sum signals, and respectively
multiplying the weighted sum signals by the estimated channel responses to
produce a plurality of demodulated signals; an adder for summing said plurality of demodulated signals; and a decision circuit for making a threshold decision on the summed
demodulated signals to produce a decision output as said symbol output,
wherein said error detection circuitry is arranged to: multiply the decision output by the estimated channel responses to
produce a plurality of multiplied decision outputs, and detect a plurality of differences between said plurality of multiplied
decision outputs and the despread signals to produce said plurality of errors.
Claim 9
Dependent Claim
23 words
A code division multiple access communication receiver as claimed in
Claim 7 or 8, wherein said symbol output is a known symbol value.
Claim 10
Dependent Claim
55 words
A code division multiple access communication receiver as claimed in
any of Claims 7 to 9, wherein said weight control circuitry is arranged to: detect correlations between the despread signals from said despreaders
and said combined error signal to produce correlation values; integrate the correlation values over a symbol interval to produce said
weight coefficients.
Claim 11
Dependent Claim
35 words
A code division multiple access communication receiver as claimed in
any of Claims 7 to 9, wherein said weight control circuitry is arranged to
update said weight coefficients according to minimum mean square error
algorithm.
Claim 12
Independent Claim
140 words
A method of processing a spread spectrum signal, comprising
the steps of: a) receiving signals from a plurality of antennas spaced a
correlation distance apart from each other, respectively weighting the
received signals with weight coefficients and combining the weighted signals
to produce a weighted sum signal; b) separating the weighted sum signal into multipath components
which respectively correspond to propagation paths of a signal transmitted
from a user station; c) respectively despreading the separated multipath components
with a chip sequence assigned to the user station to produce a plurality of
despread signals at symbol intervals; d) detecting a plurality of errors between a symbol output and the
despread signals and combining said plurality of errors to produce a
combined error signal; and e) detecting correlations between said received signals and the
combined error signal to produce said weight coefficients.
Claim 13
Independent Claim
115 words
A method as claimed in daim 12, further comprising the
steps of: estimating channel responses of said propagation paths from the
despread signals of the step (c); multiplying the despread signals by the estimated channel responses
to produce a plurality of demodulated signals; summing said plurality of demodulated signals; making a threshold decision on the summed demodulated signals
to produce a decision output as said symbol output, wherein the step (d)
comprises the steps of: multiplying the decision output by the estimated channel responses
to produce a plurality of multiplied decision outputs; and detecting a plurality of differences between said plurality of
multiplied decision outputs and the despread signals to produce said
plurality of errors.
Claim 14
Independent Claim
165 words
A method of processing a spread spectrum signal, comprising
the steps of: a) receiving signals from a plurality of antennas spaced a
correlation distance apart from each other, respectively despreading the
received signals with a chip sequence assigned to a user station to produce a
plurality of despread signals at chip intervals; b) respectively weighting the despread signals by weight
coefficients; c) separating each of the weighted despread signals into a plurality
of multipath components which respectively correspond to propagation
paths of a signal transmitted from the user station; d) summing the separated multipath components to produce a
plurality of weighted sum signals each representative of the sum of the
multipath components of same arrival time; e) detecting a plurality of errors between a symbol output and
said plurality of weighted sum signals and combining said plurality of errors
to produce a combined error signal; and f) detecting correlations between said plurality of despread signals
and said combined error signal to produce said weight coefficients.
Claim 15
Dependent Claim
119 words
A method as claimed in claim 14, further comprising the
steps of: estimating channel responses of said propagation paths from said
weighted sum signals of the step (d); respectively multiplying the weighted sum signals by the estimated
channel responses to produce a plurality of demodulated signals; summing said plurality of demodulated signals; and making a threshold decision on the summed demodulated signals
to produce a decision output as said symbol output, wherein the step (e)
comprises the steps of: multiplying the decision output by the estimated channel responses
to produce a plurality of multiplied decision outputs; and detecting a plurality of differences between said plurality of
multiplied decision outputs and the despread signals to produce said
plurality of errors.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.