Method and apparatus for transmitting and receiving signals in multi-antenna communication system

• US 9,614,594 B2
• Filed: 11/15/2012
• Issued: 04/04/2017
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Yung Soo
• Primary Examiner(s): Yao, Kwang B
• Assistant Examiner(s): CHOWDHURY, HARUN UR R
• Application Number:
  US13/677,660
• Publication Number:
  US 20130121342A1
• Time in Patent Office: 1,601 Days
• Field of Search: 370436, 370437, 370329, 370330, 370334, 370252, 370338, 370328, 375141, 375219, 375296, 375267
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation
• CPC Class Codes: H04W 72/56 based on priority criteria

Abstract

A method for transmitting a signal in a multi-antenna system is provided. The method includes designating an analog beam to a plurality of generated modulation symbol sequences corresponding to a plurality of antenna ports, for each antenna port of the plurality, multiplexing signals, to which a beam is designated by the beam assignment, to a plurality of beam groups each having the same antenna beam combination, mapping beam group signals generated by the beam multiplexing, to at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol and time and frequency resources, generating OFDM symbol signals corresponding to one or more antenna beams by OFDM-converting the beam group signals according to the resource mapping, converting the OFDM symbol signals into analog Radio Frequency (RF) signals, and transmitting the analog RF signals via a plurality of antenna elements by carrying the analog RF signals on associated antenna beams by analog beamforming.

Claims

1. A method for transmitting a signal in a multi-antenna system, the method comprising:

precoding a plurality of modulation symbols to generate P precoded signals corresponding to P antenna ports for each user equipment among N user equipments;

designating P analog beams to the P precoded signals for each user equipment, in which each analog beam has a beam pattern defined by a beam width and a beam direction that is different for different analog beams;

multiplexing P*N precoded signals for the N user equipments, such that the precoded signals of a same analog beam are grouped into a same group signal;

generating J orthogonal frequency division multiplexing (OFDM) signals based on the multiplexed precoded signals; and

converting the J OFDM signals into J Radio frequency (RF) signals to transmit on the J analog beams.

2. The method of claim 1, further comprising:

phase-shifting each of the RF signals depending on phase shift values corresponding to antenna elements;

power-amplifying the phase-shifted signals depending on power control values corresponding to the antenna elements; and

summing the power-amplified signals corresponding to each antenna element,

wherein the phase shift values and the power control values are determined based on corresponding analog beams.

3. The method of claim 1, further comprising:

phase-shifting each of the RF signals depending on a plurality of phase shift values corresponding to antenna elements;

at least one of transferring the phase-shifted signals to the antenna elements and blocking the phase-shifted signals from the antenna elements;

summing signals transferred to the antenna elements for each individual antenna element; and

power-amplifying the summed signals independently depending on power control values corresponding to the antenna elements,

wherein the phase shift values and the power control values are determined based on corresponding analog beams.

4. The method of claim 1, further comprising:

phase-shifting each of the RF signals depending on phase shift values corresponding to antenna elements;

summing the phase-shifted signals for each individual antenna element; and

power-amplifying the summed signal depending on power control values corresponding to the antenna elements,

wherein the phase shift values and the power control values are determined based on corresponding analog beams.

5. The method of claim 1, further comprising:

transferring each of the RF signals to at least one of antenna elements based on a switching pattern, determined based on corresponding analog beams.

6. The method of claim 1, further comprising:

prioritizing the plurality of group signals comprising the P*N precoded signals by scheduling;

determining whether interference between an analog beam corresponding to each of the group signals and a previous analog beam is less than a reference value in order of the priorities of the group signals;

mapping precoded signals included in a group signal having interference less than the reference value to OFDM symbols of the OFDM signals; and

repeating the determining and the mapping until at least one of resources of all assignable OFDM symbols are assigned and transmission for the J analog beams is considered.

7. The method of claim 1, wherein the plurality of modulation symbols are mapped to a plurality of layers before precoding.

8. The method of claim 7, wherein the P precoded signals are generated based on at least one precoding matrix.

9. The method of claim 1, further comprising:

before the converting, mapping the OFDM signals for different user equipments corresponding to a same analog beam, to different frequency resources of a same time resource.

10. The method of claim 1, further comprising:

before the converting, mapping the OFDM signals for user equipments corresponding to a same analog beam, to different time resources of a same frequency resource.

11. The method of claim 1, further comprising:

before the converting, identify an analog beam having less interference among the J analog beams; and

mapping at least one OFDM signal of the identified analog beam to a same time-frequency resource.

12. The method of claim 1, wherein a first analog beam that carries a first precoded signal for a first user equipment of the plurality of user equipments is determined as an optimal analog beam selected for the first user equipment.

13. The method of claim 1,

wherein, such that for J=m*P, (where m=1, 2, 3, . . .), m group signals are selected among the plurality of group signals, and the precoded signals of the selected m group signals are mapped to the J OFDM signals and are transmitted at a same time resource, and

wherein precoded signals of group signals other than the selected m group signals are transmitted at different times than the selected m group signals.

14. An apparatus for transmitting a signal in a multi-antenna system, the apparatus comprising:

at least one processor configured to;

precode a plurality of modulation symbols to generate P precoded signals corresponding to P antenna ports for each user equipment among N user equipments,

designate P analog beams to the P precoded signals for each user equipment, in which each analog beam has a beam pattern defined by a beam width and a beam direction that is different for different analog beams,

multiplex P*N precoded signals for the N user equipments, such that the precoded signals of a same analog beam are grouped into a same group signal,

generate J orthogonal frequency division multiplexing (OFDM) signals based on the multiplexed precoded signals, and

convert the J OFDM signals into J radio frequency (RF) signals; and

a transceiver configured to transmit the RF signals through the J analog beams.

15. The apparatus of claim 14,

wherein the transceiver further comprises:

a phase shifting unit configured to phase-shift each of the RF signals depending on phase shift values corresponding to the antenna elements;

a power amplification unit configured to power-amplify the phase-shifted signals depending on power control values corresponding to the antenna elements; and

a summation unit configured to sum the power-amplified signals corresponding to each antenna element, and

wherein the phase shift values and the power control values are determined based on corresponding analog beams.

16. The apparatus of claim 14,

wherein the transceiver further comprises:

a phase shifting unit configured to phase-shift each of the RF signals depending on a plurality of phase shift values corresponding to the antenna elements;

a switching unit configured to transfer the phase-shifted signals to the antenna elements or block the phase-shifted signals from the antennal elements;

a plurality of summers configured to sum signals transferred to the antenna elements for each individual antenna element; and

a plurality of power amplifiers configured to power amplify the summed signals independently depending on power control values corresponding to the antenna elements, and

wherein the phase shift values and the power control values are determined based on corresponding analog beams.

17. The apparatus of claim 14,

wherein the transceiver further comprises:

a phase shifting unit configured to phase-shift each of the RF signals depending on a plurality of phase shift values corresponding to the antenna elements;

a plurality of summers configured to sum the phase-shifted signals for each individual antenna element; and

a plurality of power amplifiers configured to power-amplify the summed signals independently depending on power control values corresponding to the antenna elements, and

wherein the phase shift values and the power control values are determined based on corresponding analog beams.

18. The apparatus of claim 14,

wherein the transceiver comprises a plurality of switches configured to transfer each of the RF signals to at least one of a plurality of antenna elements based on a switching pattern

determined based on corresponding analog beams.

19. The apparatus of claim 14,

wherein the at least one processor is further configured to:

prioritize a plurality of group signals comprising the P*N precoded signals by scheduling,

determine whether interference between an analog beam corresponding to each of the group signals and a previous analog beam is less than a reference value, in order of the priorities of the group signals,

map precoded signals included in a group signal having interference less than the reference value, to the OFDM symbols, and

repeat the determination and the mapping until at least one of resources of all assignable OFDM symbols are assigned and transmission for the J analog beams is considered.

20. The apparatus of claim 14, wherein the plurality of modulation symbols are mapped to a plurality of layers before precoding.

21. The apparatus of claim 20, wherein the P precoded signals are generated based on at least one precoding matrix.

22. The apparatus of claim 14,

wherein the at least one processor is further configured to map the OFDM signals for different user equipments corresponding to a same analog beam to different frequency resources of a same time resource.

23. The apparatus of claim 14,

wherein the at least one processor is further configured to map the OFDM signals corresponding for different user equipments corresponding to a same analog beam to different time resources of a same frequency resource.

24. The apparatus of claim 14,

wherein the at least one processor is further configured to:

identify an analog beam having less interference among the J analog beams, and

map at least one OFDM signal of the identified analog beam to a same time-frequency resource.

25. The apparatus of claim 14, wherein a first analog beam that carries a first precoded signal for a first user equipment of the plurality of user equipments is determined as an optimal analog beam selected for the first user equipment.

26. The apparatus of claim 14,

wherein, such that for J=m*P, (where m=1, 2, 3, . . .), m group signals are selected among the plurality of group signals, and the precoded signals of the selected m group signals are mapped to the J OFDM signals and are transmitted at a same time resource, and

wherein precoded signals of group signals other than the selected m group signals are transmitted at different times than the selected m group signals.

27. An apparatus for receiving a signal in a multi-antenna system, the apparatus comprising:

a plurality of antenna elements for receiving signals from a transmitter;

low-noise-amplifiers for low-noise-amplifying the received signals;

a phase shifting unit for outputting a plurality of reception beam signals by applying phase shift values determined by a digital processing unit to the amplified signals; and

a conversion unit for converting the reception beam signals into digital beam signals and for transferring the digital beam signals to the digital processing unit,

wherein the transmitter is configured to;

precode a plurality of modulation symbols to generate P precoded signals corresponding to P antenna ports for each user equipment among N user equipments,

designate P analog beams to the P precoded signals for each user equipment, in which each analog beam has a beam pattern defined by a beam width and a beam direction that is different for different analog beams,

multiplex P*N precoded signals for the N user equipments, such that the precoded signals of a same analog beam are grouped into a same group signal,

generate J orthogonal frequency division multiplexing (OFDM) signals based on the multiplexed precoded signals, and

convert the J OFDM signals into J radio frequency (RF) signals to transmit on the J analog beams.

28. The apparatus of claim 27, wherein a first analog beam that carries a first precoded signal for a first user equipment of the plurality of user equipments is determined as an optimal analog beam selected for the first user equipment.

29. The apparatus of claim 27,

wherein, such that for J=m*P, (where m=1, 2, 3, . . .), m group signals are selected among the plurality of group signals, and the precoded signals of the selected m group signals are mapped to the J OFDM signals and are transmitted at a same time resource, and

wherein precoded signals of group signals other than the selected m group signals are transmitted at different times than the selected m group signals.

30. An apparatus for receiving a signal in a multi-antenna system, the apparatus comprising:

a plurality of directional antenna elements, arranged in different directions, for receiving signals from a transmitter;

low-noise-amplifiers for low-noise-amplifying the received signals;

a switching unit for selecting at least one of the amplified signals as a reception beam for each individual antenna element; and

a conversion unit for converting the signals from the switching unit into digital beam signals and for transferring the digital beam signals to the digital processing unit,

wherein the transmitter is configured to;

precode a plurality of modulation symbols to generate P precoded signals corresponding to P antenna ports for each user equipment among N user equipments,

designate P analog beams to the P precoded signals for each user equipment, in which each analog beam has a beam pattern defined by a beam width and a beam direction that is different for different analog beams,

multiplex P*N precoded signals for the N user equipments, such that the precoded signals of a same analog beam are grouped into a same group signal;

generating J orthogonal frequency division multiplexing (OFDM) signals based on the multiplexed precoded signals, and

converting the J OFDM signals into J radio frequency (RF) signals to transmit on the J analog.

31. The apparatus of claim 30, further comprising

a phase shifting unit configured to generate a plurality of reception beam signals by applying phase shift values determined by a digital processing unit to the selected at least one of the amplified signals by the switching unit and outputting the plurality of reception beam signals to the conversion unit.

32. The apparatus of claim 30, wherein a first analog beam that carries a first precoded signal for a first user equipment of the plurality of user equipments is determined as an optimal analog beam selected for the first user equipment.

33. The apparatus of claim 30,

wherein, such that for J=m*P, (where m=1, 2, 3, . . .), m group signals are selected among the plurality of group signals, and the precoded signals of the selected m group signals are mapped to the J OFDM signals and are transmitted at a same time resource, and

wherein precoded signals of group signals other than the selected m group signals are transmitted at different times than the selected m group signals.