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EP0892504A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

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
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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 06:38
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.

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