EP0892504A2
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EP
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Method of and apparatus for digital radio signal reception
Assignee: TIM SpA
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Filing: 1998-05-15
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Granted: —
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Expires: 2018-05-15
Abstract
Abstract A receiver is described, for instance for GSM systems, wherein a plurality of digital signals each comprising a training sequence (x p (t)) usable to generate an estimation of the transmission channel are received in diversity (A.1 ... A.N) in the form of a plurality of replicas (10.1 ... 10.N) each comprising a respective replica of the training sequence. The received digital signal is subjected to a delaying action thereby obtaining a plurality of versions of such signal, each comprising a respective set of signal replicas. Each version is subjected to a respective filtering action (23.1 ... 23.N) independently from the other versions, by employing a respective first set of filtering coefficients (w* 11 ... w* N1 ... w* Nj ) obtained starting from a respective initial set of filtering coefficients. This respective initial set is obtained by performing, for each replica of the received signal, a filtering action exploiting a respective second set of filtering coefficients identified as a signal (u (t)) able to generate, by convolution (u (t) * x p (t)) with the training sequence, a unitary function δ (t) on a given time window, preferably on one bit. The filtering coefficients of the first set are derived starting from said initial set of filtering coefficients through an MMSE adaptation, preferably with a initial rapid convergence phase of the RLS type followed by an optimisation phase of the LMS type.
Inventors
- 👤 Andrew Peter Ansbro
- 👤 Spase Drakul
- 👤 Antonio Fanigliulo
- 👤 Gianluca Fontana
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 04:35
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0837; H04B7/0842; H04B7/0848; H04B7/0851; H04B7/0845; H04B7/0891
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
253 words
Method of receiving digital signals comprising a training sequence x p (t) usable to
generate an estimate of the transmission channel, wherein the digital signal is
received in diversity as a plurality of signal replicas (10.1 ... 10.N) each comprising
a respective replica x p (t) * a (t) of said training sequence, the method being
characterised in that it comprises the following operations: generating a plurality of versions of the received digital signal separated by
a given delay interval (T), each version comprising a respective set of signal
replicas; subjecting each of said versions of the received digital signal to a respective
filtering action (23.1 ... 23.j) independently of the other versions; said respective
filtering action being performed on each of said versions by applying to the
respective set of signal replicas a respective first set of filtering coefficients
(w* 11 ...w* N1; ... ; w* 1j ... w* Nj ) obtained starting from a respective initial set of
filtering coefficients; obtaining said respective initial set of filtering coefficients by subjecting the
respective version of the received digital signal to a respective second filtering
action (27.1 ... 27.j), performed independently of the respective second filtering
actions effected on the other versions of the received digital signal; each of
said respective second filtering actions being performed with a respective
second set of filtering coefficients identified as a signal (u (t)) able to generate,
by convolution (u (t) * x p (t)) with said training sequence, a unitary function on
a given time slot.
Claim 2
Dependent Claim
44 words
Method as claimed in claim 1, characterised in that said respective second set of
filtering coefficients (u (t)) are identified a a signal able to generate by convolution
(u (t)) * x p (t)) with said training sequence a unitary function on one bit.
Claim 3
Dependent Claim
39 words
Method as claimed in claim 1 or 2, characterised in that said respective first set of
filtering coefficients is generated starting from said respective initial set of filtering
coefficients by means of a Minimum Mean Square Error (MMSE) adaptation.
Claim 4
Dependent Claim
32 words
Method as claimed in claim 3, characterised in that said adaptation is chosen in the
group constituted by a Recursive Least Square (RLS) adaptation and by a Least
Mean Square (LMS) adaptation.
Claim 5
Dependent Claim
39 words
Method as claimed in claim 4, characterised in that said minimum mean square error
adaptation comprises an initial rapid convergence phase of the recursive least
square (RLS) type followed by a phase of the least minimum square (LMS) type.
Claim 6
Dependent Claim
146 words
Method of receiving digital radio signals including a training sequence x p (t) usable
to generate an estimate of the transmission channel, wherein the digital signal is
received in diversity as a plurality of signal replicas (10.1 ... 10.N) each comprising
a respective replica x p (t) * a (t) of said training sequence, the method being
characterised in that it comprises the operation of performing an initial estimate of
the transmission channel by subjecting each replica of the training sequence to a
respective filtering action (27.1 ... 27.N), performed independently of filtering actions
effected on the other replicas of the training sequence; each of said filtering actions
being performed with a respective set of filtering coefficients identified as a signal
(u (t)) able to generate, by convolution (u (t) * x p (t)) with said training sequence,
a unitary function on a given time slot.
Claim 7
Dependent Claim
281 words
Apparatus for the reception of digital signals comprising a training sequence (x p (t))
usable to generate an estimate of the transmission channel, the apparatus
comprising a plurality of antenna operating in diversity, so that the digital signal is
received in the form of a plurality of signal replicas (10.1, .., 10.N) comprising each
a respective replica (x p (t) * a (t)) of said training sequence, the apparatus being
characterised in that it further comprises delay means for generating a plurality of versions of the received digital signal
separated by a given delay interval (T), each version comprising a respective
set of signal replicas, first filtering means (23.1, 23.2 ... 23.j) for subjecting each of said versions of
the digital signal received to a respective filtering action independently from
the other versions; said respective second filtering action being performed on
each of said versions by applying to the respective set of signal replicas a
respective second set of filtering coefficients (w* 11 ... w* N1 ...w* 11 , w* 1j ... w* Nj )
obtained starting from a respective initial set of filtering coefficients determined, second filtering means (27.1, 27,2 .... 27.N) for obtaining said respective initial
set of filtering coefficients by subjecting the respective replica of said training
sequence to a respective second filtering action performed independently from
the respective second filtering actions performed on the other respective
replica of said training sequence; each of these respective second filtering
actions being performed with a respective second set of filtering coefficient
identified as a signal (u (t)) able to generate by convolution (u (t) * x p (t)) with
said training sequence a unitary function on a given time slot.
Claim 8
Dependent Claim
46 words
Apparatus as claimed in claim 7, characterised in that said respective set (second
set) of filtering coefficients (u (t)) is identified as a signal able to generate by
convolution (u (t) * x p (t)) with said training sequence a unitary function over a preset
interval.
Claim 9
Dependent Claim
45 words
Apparatus as claimed in claim 8, characterised in that it comprises an adaptation
module (24) which calculates said respective first set of filtering coefficients starting
from said respective initial set of filtering coefficients by means of an adaptation of
the minimum mean square error type.
Claim 10
Dependent Claim
32 words
Apparatus as claimed in claim 9, characterised in that said adaptation module (24)
operates according to an algorithm chosen in the group comprising recursive least
square adaptation and least mean square adaptation.
Claim 11
Dependent Claim
36 words
Apparatus as claimed in claim 10, characterised in that said adaptation module (24)
operates with an initial rapid convergence phase of the recursive least square type
followed by a phase of the least mean square type.
Claim 12
Dependent Claim
59 words
Apparatus as claimed in any of claims 9 to 11, characterised in that said adaptation
module (24) is arranged to generate a respective first set of filtering coefficients for
each of a plurality of users within of a same cell of a digital radio communication
system in which said users use the same physical channel (time - frequency
channel).
Claim 13
Dependent Claim
162 words
Apparatus for the reception of digital signals comprising a training sequence (x p (t))
usable to generate an estimate of the transmission channel, the apparatus
comprising a plurality of antenna operating in diversity, so that the digital signal is
received in the form of a plurality of signal replicas (10.1, .., 10.N) comprising each
a respective replica (x p (t) * a (t)) of said training sequence, the apparatus being
characterised in that it further comprises filtering means (27.1, 27,2 ... 27.N) for
performing an initial estimate of the transmission channel by subjecting a respective
replica of said training sequence to a filtering action performed independently from
the filtering actions performed on the other replicas of said training sequence; each
of these filtering actions being performed with a respective set of filtering coefficients
identified a a signal (u (t)) able to generate by convolution (u (t) * x p (t)) with said
training sequence a unitary function on a given time slot.
References Cited (Backward Citations)
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