Unified design and centralized scheduling for dynamic SIMO, SU-MIMO and MU-MIMO operation for RL transmissions

• US 8,675,768 B2
• Filed: 06/13/2013
• Issued: 03/18/2014
• Est. Priority Date: 10/31/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Xu, Hao, Malladi, Durga Prasad
• Primary Examiner(s): Lugo, David B.
• Application Number:
  US13/917,461
• Publication Number:
  US 20130279617A1
• Time in Patent Office: 278 Days
• Field of Search: 375/260, 375/267, 375/295, 375/299
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04B 7/0684 using different training sequences per antenna
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels

Abstract

Systems and methods facilitate pilot signal design, power control, data rate determination, and channel assignment in the reverse link of a wireless communication system for dynamic scheduling and joint operation in SIMO, SU-MIMO, and MU-MIMO. Pilot signal is based on periodic transmissions of multiple sounding reference sequences for channel estimation. Power control is based on a reference signal at a predetermined power spectral density (PSD) level, and on an offset PSD determined and signaled based on an antenna that transmits the reference signal, other cell interference, and power amplifier headroom. PSD levels for SIMO/MIMO data transmissions are determined based on channel estimates and the predetermined PSD and offset PSD. Such data PSD levels are employed to generate data rates, and to dynamically schedule data streams for communication. Communication resources are conveyed through a channel assignment with an overhead that depends on the maximum multiplexing order of the estimated channel.

Claims

1. A method employed in wireless communication system, the method comprising:

transmitting at least one power control reference signal from an antenna selected from a group of M antennas, with M a positive integer;

conveying a power headroom report from the antenna employed to report the at least one power control reference signal, wherein the power headroom report is based at least in part on a reference power spectral density (PSD) level for transmitting the at least one power control reference signal, and the power headroom report adjusts the power that a base station assigns to a mobile terminal for transmitting data in a reverse link; and

transmitting a pilot signal from each antenna in the set of M antennas for estimating a multiple-input multiple output channel when M>

1, and a SIMO channel when M=1,

wherein the power headroom report is determined based at least on a power headroom of a power amplifier in the physical antenna selected to report at least one power control reference signal.

2. The method of claim 1, the at least one power control reference signal includes a CQI channel.

3. The method of claim 1, the transmitted reference signal is at least one of a constant amplitude zero autocorrelation (CAZAC) sequence.

4. The method of claim 1, the power headroom report is estimated based at least on a load indicator associated with inter-cell interference.

5. The method of claim 1, the power headroom report is tabulated according to a modulation and coding scheme assigned to a mobile terminal.

6. The method of claim 1, further comprising determining whether to report the at least one power control reference signal from a physical antenna or a virtual antenna.

7. The method of claim 1, the group of M antennas is a set of physical antennas.

8. The method of claim 1, the group of M antennas is a set of virtual antennas.

9. The method of claim 1, the Power headroom report is determined based at least on a remaining power headroom of a power amplifier PA in a physical antenna available in the set of physical antennas combined to compose the virtual antenna employed to report the at least one power control reference signal.

10. The method of claim 1, transmitting a pilot signal includes transmitting the pilot signal periodically.

11. The method of claim 1, wherein the pilot signal is at least one of a constant amplitude zero autocorrelation (CAZAC) sequence.

12. The method of claim 1, wherein the transmitted pilot signal is at least one of a pseudorandom code, or a pseudonoise sequence.

13. The method of claim 1, wherein the transmitted pilot signal is at least one of a Gold sequence, a Walsh-Hadamard sequence, an exponential sequence, a Golomb sequence, a Rice sequence, an M-sequence, or a generalized Chirp-like (GCL) sequence.

14. A wireless communications device comprising:

means for transmitting at least one power control reference signal from an antenna selected from a group of M antennas, with M a positive integer;

means for conveying a power headroom report from the antenna employed to report the at least one power control reference signal, wherein the power headroom report is based at least in part on a reference power spectral density (PSD) level for transmitting the at least one power control reference signal, and the power headroom report adjusts the power that a base station assigns to a mobile terminal for transmitting data in a reverse link; and

means for transmitting a pilot signal from each antenna in the set of M antennas for estimating a multiple-input multiple output channel when M>

1, and a SIMO channel when M=1,

wherein the power headroom report is determined based at least on a power headroom of a power amplifier in the physical antenna selected to report at least one power control reference signal.

15. A computer program product, comprising

a non-transitory computer-readable medium including:

code for causing at least one computer to transmit at least one power control reference signal from an antenna selected from a group of M antennas, with M a positive integer;

code for causing the at least one computer to convey a power headroom report from the antenna employed to report the at least one power control reference signal, wherein the power headroom report is based at least in part on a reference power spectral density (PSD) level for transmitting the at least one power control reference signal, and the power headroom report adjusts the power that a base station assigns to a mobile terminal for transmitting data in a reverse link; and

code for causing the at least one computer to transmit a pilot signal from each antenna in the set of M antennas for estimating a multiple-input multiple output channel when M>

1, and a SIMO channel when M=1,

wherein the power headroom report is determined based at least on a power headroom of a power amplifier in the physical antenna selected to report at least one power control reference signal.

16. A wireless communication device, comprising:

a processor configured to

transmit at least one power control reference signal from an antenna selected from a group of M antennas, with M a positive integer

convey a power headroom report from the antenna employed to report the at least one power control reference signal, wherein the power headroom report is based at least in part on a reference power spectral density (P SD) level for transmitting the at least one power control reference signal, and the power headroom report adjusts the power that a base station assigns to a mobile terminal for transmitting data in a reverse link, and

transmit a pilot signal from each antenna in the set of M antennas for estimating a multiple-input multiple output channel when M>

1, and a SIMO channel when M=1,

wherein the power headroom report is determined based at least on a power headroom of a power amplifier in the physical antenna selected to report at least one power control reference signal; and

a memory coupled to the processor.