Signal separation in an orthogonal time frequency space communication system using MIMO antenna arrays

• US 10,020,854 B2
• Filed: 12/09/2016
• Issued: 07/10/2018
• Est. Priority Date: 06/25/2012
• Status: Active Grant

• Current Assignee: Cohere Technologies Inc
• Original Assignee: Cohere Technologies Inc
• Inventors: Hadani, Ronny, Rakib, Shlomo Selim
• Primary Examiner(s): Puente, Eva
• Application Number:
  US15/374,995
• Publication Number:
  US 20170222700A1
• Time in Patent Office: 578 Days
• Field of Search: 375267, 370328, 370474, 370329
• CPC Class Codes: H04B 1/02 Transmitters
• CPC Class Codes: H04B 1/12 Neutralising, balancing, or compensation arrangements
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04J 11/0026 of multi-user interference
• CPC Class Codes: H04J 2011/0016 with FDM/FDMA and TDM/TDMA
• CPC Class Codes: H04L 23/02 adapted for orthogonal signalling
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2636 with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
• CPC Class Codes: H04L 27/26362 Subcarrier weighting equivalent to time domain filtering, e.g. weighting per subcarrier multiplication arrangements for removing intersymbol interference at the transmitter end H04L25/03343
• CPC Class Codes: H04L 27/2639 Modulators using other transforms, e.g. discrete cosine transforms, Orthogonal Time Frequency and Space [OTFS] or hermetic transforms
• CPC Class Codes: H04L 27/26524 Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
• CPC Class Codes: H04L 27/2654 Filtering per subcarrier, e.g. filterbank multicarrier [FBMC]
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques
• CPC Class Codes: H04L 5/0005 Time-frequency
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 : Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 4/70 : Services for machine-to-machine communication [M2M] or machine type communication [MTC]

Abstract

A device and method for signal separation in an orthogonal time frequency space communication system using MIMO antenna arrays. The communication device includes an antenna arrangement and a receiver. The receiver is configured to receive, from the antenna arrangement, a plurality of pilot signals associated with respective locations in a time-frequency plane wherein the plurality of pilot signals were transmitted from a corresponding plurality of transmit antenna elements. The receiver is further configured to receive signal energy transmitted by the plurality of transmit antenna elements and to measure, based upon the plurality of pilot signals, a plurality of two-dimensional time-frequency coupling channels between the plurality of transmit antenna elements and the antenna arrangement. The receiver is also operative to invert a representation of each of the plurality of two-dimensional time-frequency coupling channels to provide a plurality of inverted channel representations.

Claims

1. A communication device, comprising:

an antenna arrangement;

a receiver configured to;

receive, from the antenna arrangement, a plurality of pilot signals associated with respective locations in a time-frequency plane wherein the plurality of pilot signals were transmitted from a corresponding plurality of transmit antenna elements;

receive signal energy transmitted by the plurality of transmit antenna elements;

measure, based upon the plurality of pilot signals, a plurality of two-dimensional time-frequency coupling channels between the plurality of transmit antenna elements and the antenna arrangement; and

invert a representation of each of the plurality of two-dimensional time-frequency coupling channels to provide a plurality of inverted channel representations.

2. The communication device of claim 1 wherein the receiver is further configured to use the plurality of inverted channel representations to separate the signal energy into a plurality of time-frequency planes of information.

3. The communication device of claim 1 further including a transmitter configured to transform a plurality of data elements into a two-dimensionally spread data matrix and to provide, to the antenna arrangement, a data signal modulated in accordance with the spread data matrix.

4. The communication device of claim 3 wherein the transmitter is further configured to pre-encode the plurality of data elements based upon a precoding signal received by the receiver.

5. A communication device, comprising:

an antenna arrangement;

a receiver configured to;

receive, from the antenna arrangement, a pilot signal associated with a location in a time-frequency plane wherein the pilot signal was transmitted from a transmit antenna element;

receive signal energy transmitted by the transmit antenna element;

measure, based upon the pilot signal, a two-dimensional time-frequency coupling channel between the transmit antenna element and the antenna arrangement,

invert a representation of the two-dimensional time-frequency coupling channel to provide an inverted channel representation; and

use the inverted channel representation to separate the signal energy into a time-frequency plane of information.

6. The communication device of claim 5 further including a transmitter configured to transform a plurality of data elements into a two-dimensionally spread data matrix and to provide, to the antenna arrangement, a data signal modulated in accordance with the spread data matrix.

7. The communication device of claim 6 wherein the transmitter is further configured to pre-encode the plurality of data elements based upon a precoding signal received by the receiver.

8. A method, comprising:

providing, by a set of M antennas of a receiver, a set of M received signals wherein the set of M received signals are provided in response to N information signals transmitted by a set of N transmit antennas, where M and N are greater than one;

measuring a plurality of two-dimensional coupling channels existing between the M antennas of the receiver and each of the N transmit antennas;

inverting a representation of each of the plurality of two-dimensional coupling channels to provide a plurality of inverted channel representations; and

separating, using the plurality of inverted channel representations, the M received signals into estimates of the N information signals.

9. The method of claim 8 wherein the measuring includes receiving, from each of the M antennas, a plurality of pilot signals transmitted by the N transmit antennas wherein each of the plurality of pilot signals is associated with a respective location in a time-frequency plane.