Method for transmitting an offset modulated biorthogonal multicarrier signal (BFDM/OM)
AssigneesFrance Telecom, Tdf
InventorsPierre Siohan, Cyrille Siclet
Life of this patent
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Abstract
The invention concerns a method for transmitting a biorthogonal multicarrier signal BFDM/OM, using a transmultiplexer structure providing: a modulating step, using a synthesis filter bank (11), having two 2M parallel branches, M≧2, each supplied by source data, and comprising an expander of order M and filtering means; a demodulating step, using an analysis filter bank (12), having two 2M parallel branches, each comprising a decimation unit of order M and filtering means, and delivering received data representing said source data; said filtering means being derived from a predetermined prototype modulating function.
Claims16
A method for modulating a biorthogonal frequency division multiplex/offset modulation (BFDM/OM) biorthogonal multicarrier signal, wherein a bank of synthesis filters are implemented, having 2M parallel branches, wherein M is an integer parameter and M≧2, each branch of synthesis filters being fed by source data and each comprising an expander of order M and a synthesis filter, which is derived from a predetermined prototype modulation function,
- said method performing the following steps:
- a multiplication by
- ⅇ
- j
-
- π
- 2
-
- n
- of each of said source data, providing multiplied source data;
- applying a predetermined phase shift to each source data of a set of 2M multiplied source data, wherein said predetermined phase shift is D=αM−β, with α an integer representing a reconstruction delay and β an integer between 0 and M−1, implementing a reverse Fourier transform fed by the set of 2M source data having undergone the predetermined phase shift,
- feeding 2M synthesis filters with outputs of said reverse Fourier transform,
- expansion of order M of outputs of said synthesis filters, providing synthesis filter outputs,
- grouping said synthesis filter outputs, and
- transmitting the grouped synthesis filter outputs.
A method comprising demodulating a biorthogonal frequency division multiplex/offset modulation (BFDM/OM) biorthogonal multicarrier signal wherein a bank of analysis filters are implemented having 2M parallel branches, wherein M is an integer parameter and M≧2, each branch of analysis filters comprising a decimator of order M and an analysis filter, and delivering representative data received from source data, said analysis filter being derived from a predetermined prototype modulation function, and performing the following steps:
- receiving of a transmitted signal made of inputs,
- grouping said inputs,
- decimation of order M of said inputs,
- feeding 2M analysis filters with an output of decimation of order M,
- feeding 2M phase shift multipliers with outputs of the 2M analysis filters, delivering phase-shifted outputs corresponding to a multiplication of said outputs of the 2M analysis filters by
- ⅇ
- -
- j
-
- 2
-
- π
- 2
-
- M
-
- l
-
- D
- +
- M
- 2
- ,
- wherein D is a predetermined phase shift such as D=2.s.M+d, wherein s is an integer and d is an integer between 0 and 2M−1,
- implementing a reverse Fourier transform fed by 2M branches, themselves fed by said phase-shifted outputs, delivering an estimation of the source data.
Apparatus comprising:
- a modulating device for modulating a biorthogonal frequency division multiplex/offset modulation (BFDM/OM) biorthogonal multicarrier signal, comprising a bank of synthesis filters having 2M parallel branches, wherein M is an integer parameter and M≧2, each branch of synthesis filters being fed by source data and each comprising an expander of order M and a synthesis filter, which is derived from a predetermined prototype modulation function,
- and performing:
- a multiplication by
- ⅇ
- j
-
- π
- 2
-
- n
- of each of said source data, providing multiplied source data;
- applying a predetermined phase shift to each source data of a set of 2M multiplied source data, wherein said predetermined phase shift is D=αM−β, with α an integer representing a reconstruction delay and β an integer between 0 and M−1,
- reverse Fourier transform fed by the set of 2M source data having undergone the predetermined phase shift,
- feeding 2M synthesis filters with the outputs of said reverse Fourier transform,
- expansion of order M of the outputs of said synthesis filters, providing outputs,
- grouping said outputs, and
- transmitting the grouped outputs.
A demodulation device for demodulation a biorthogonal frequency division multiplex/offset modulation (BFDM/OM) biorthogonal multicarrier signal comprising:
- a bank of analysis filters having 2M parallel branches, each branch of the bank of analysis filters comprising a decimator of order M and an analysis filter, and delivering representative data received from source data, said analysis filter being derived from a predetermined prototype modulation function,
- and performing:
- receiving of a transmitted signal made of inputs,
- grouping said inputs,
- decimation of order M of said inputs,
- feeding 2M analysis filters with the output of decimation of order M,
- feeding 2M phase shift multipliers with the outputs of the 2M analysis filters, delivering phase-shifted outputs corresponding to a multiplication of said outputs of the 2M analysis filters by
- ⅇ
- -
- j
-
- 2
-
-
- π
- 2
-
- M
-
- l
-
- D
- +
- M
- 2
- ,
- wherein D is a predetermined phase shift such as D=2.s.M+d, wherein s is an integer and d is an integer between 0 and 2M−1,
- reverse Fourier transform fed by 2M branches, themselves fed by said phase-shifted outputs, delivering an estimation of the source data.
Dependencies are inferred from the claim text.