Transmitter, receiver and a method for digital multiple sub-band processing

Patent metadata

Field	Value
Publication number	US-10700897-B2
Application number	US-201615358164-A
Country	US
Kind code	B2
Filing date	Nov 22, 2016
Priority date	Jun 10, 2011
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

Highly efficient digital domain sub-band based receivers and transmitters.

First claim

We claim:

1. A receiver that comprises:
a first serial to parallel converter arranged to receive first digital signals that represent optical signals of a first polarity, and to output the first digital signals via multiple outputs;
a first polyphase finite impulse response (FIR) filter array coupled between the first serial to parallel converter and to a first inverse fast Fourier transform (IFFT) module;
a second serial to parallel converter arranged to receive second digital signals that represent optical signals of a second polarity, and to output the second digital signals via multiple outputs;
a second polyphase finite impulse response (FIR) filter array coupled between the second serial to parallel converter and to a second (IFFT) module;
multiple sub-band processor modules; wherein each sub-band processor module is coupled to inputs of a same order of the first and second IFFT modules;
wherein the sub-band processor modules are Orthogonal Frequency Division Multiplex (OFDM) sub-band receiver modules; and
wherein the receiver comprises a de-mapper and a data multiplexor that follows the multiple OFDM sub-band receiving modules.

2. A receiver that comprises:
a first serial to parallel converter arranged to receive first digital signals that represent optical signals of a first polarity, and to output the first digital signals via multiple outputs;
a first polyphase finite impulse response (FIR) filter array coupled between the first serial to parallel converter and to a first inverse fast Fourier transform (IFFT) module;
a second serial to parallel converter arranged to receive second digital signals that represent optical signals of a second polarity, and to output the second digital signals via multiple outputs;
a second polyphase finite impulse response (FIR) filter array coupled between the second serial to parallel converter and to a second (IFFT) module;
multiple sub-band processor modules; wherein each sub-band processor module is coupled to inputs of a same order of the first and second IFFT modules; and
a coherent optical front end and two pairs of analog to digital converters (ADCs);
wherein the coherent optical front end is arranged to:
receive the optical signals of the first and second polarity;
provide analog signals representative of the optical signals of the first polarization to a first pair of ADCs, and
provide analog signals representative of the optical signals of the second polarization to a second pair of ADCs;

wherein the first pair of ADCs is coupled to the first serial to parallel converter; and
wherein the second pair of ADCs is coupled to the second serial to parallel converter.

3. The receiver according to claim 1 , wherein each OFDM sub-band receiving module comprises: two sequentially coupled sets of components, each sequentially coupled set of components comprises a sub-band impairment compensator, a serial to parallel conversion and cyclic prefix drop module, a 2N-points fast Fourier transform (FFT) module and a half band decimator; a pair of parallel to parallel converters; a plurality of dual input dual output (2×2 MIMO) equalization modules, wherein different pairs of outputs of the half band decimators for the two polarizations are coupled to pairs of inputs of different 2×2 MIMO equalization modules; wherein each 2×2 MIMO equalization module comprises a pair of outputs that are coupled to inputs of a same order of the pair of parallel to parallel converters; and a pair of carrier recovery and decision modules, each carrier recovery and decision module is coupled to a parallel to parallel converter of the pair of parallel to parallel converters.

4. The receiver according to claim 1 wherein the sub-band processors comprise two sequentially coupled sets of components, each sequentially coupled set of components comprises a sub-band impairment compensator, a serial to parallel conversion and cyclic prefix drop module, a 2N-points Fast Fourier transform (FFT) module and a half band decimator; a pair of parallel to parallel converters; a plurality of dual input dual output (2×2 MIMO) equalization modules, wherein different pairs of outputs of a same order of the half band decimators for the two polarizations are coupled to pairs of inputs of different 2×2 MIMO equalization modules; wherein each 2×2 MIMO equalization module comprises a pair of outputs that are coupled to inputs of a same order of the pair of parallel to parallel converters.

5. The receiver according to claim 4 wherein the carrier recovery and decision modules are multiple-symbol differential detection (MSDD) decoders.

6. The receiver according to claim 4 wherein each sub-band impairment compensator comprises the cascade of an in-phase quadrature imbalance (IQI) compensator, a mixer and a delay unit.

7. The receiver according to claim 4 wherein each sub-band impairment compensator comprises a cascade of an in-phase quadrature imbalance (IΩI) compensator, a mixer and a delay unit.

8. The receiver according to claim 4 wherein the half-band decimator is filterless, and is arranged to route an N-points input either into a high or a low half-band of N points out of 2N inputs, dropping the remaining N points.

9. The receiver according to claim 7 wherein the half-band decimator is filterless, and is arranged to route a N points input either into a high or a low half-band of N points out of its 2N inputs, dropping the remaining N points.

10. The receiver according to claim 4 wherein the half-band decimator is arranged to perform a cyclic shift for odd numbered sub-band indexes module.

11. The receiver according to claim 7 wherein the half-band decimator is arranged to perform a cyclic shift for odd numbered sub-band indexes module.

12. The receiver according to claim 4 wherein the sub-band processors are arranged to feed an array of 2Nssc IFFT modules wherein Nssc IFFT modules form a sub-array corresponding to X polarization of signals and Nssc IFFT modules form a sub-array correspond to Y polarization of signals; the number Nssc divides the number P of sub-band processors; The sub-band processors are partitioned into P/Nssc groups; the X-outputs of the sub-band processors in the g-th group are uniformly spread onto the inputs of the g-th IFFT in the X sub-array via serial to parallel converters; the Y-outputs of the sub-band processors in the g-th group are uniformly spread onto the g-th IFFT in the Y sub-array via serial to parallel converters; the number of output ports of the serial to parallel converters used to perform the spreadings is given by the IFFT size divided by the number of sub-band processors.

13. The receiver according to claim 12 wherein each sub-band processor module comprises: two sequentially coupled sets of components, each sequentially coupled set of components comprises a sub-band impairment compensator, a serial to parallel conversion and cyclic prefix drop module, a 2N-points fast Fourier transform (FFT) module and a half band decimator; a pair of parallel to parallel converters; a plurality of dual input dual output (2×2 MIMO) equalization modules, wherein different pairs of outputs of the half band decimators for the two polarizations are coupled to pairs of inputs of different 2×2 MIMO equalization modules; wherein each 2×2 MIMO equalization module comprises a pair of outputs that are coupled to inputs of a same order of the pair of parallel to parallel converters.

14. The receiver according to claim 4 , further comprising a joint IQI, Carrier Frequency Offset (CFO), Coarse Timing Offset (CTO), Sampling Frequency Offset (SFO) estimation module that is coupled to the mixer and to the delay unit

Assignees

• Nazarathy Moshe
• Tolmachev Alex
• Technion Res & Development Found Ltd

Inventors

• Nazarathy Moshe
• Tolmachev Alex

Classifications

• H04L27/26546

  with oversampling · CPC title

• H04L27/26538

  Filtering per subband or per resource block, e.g. universal filtered multicarrier [UFMC] or generalized frequency division multiplexing [GFDM] · CPC title

• H04L27/26526

  with inverse FFT [IFFT] or inverse DFT [IDFT] demodulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] receiver or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM] · CPC title

• H04B7/0452

  Multi-user MIMO systems · CPC title

• H03H17/0266

  Filter banks · CPC title