CHANNEL SOUNDING FOR IMPROVED SYSTEM PERFORMANCE

• US 20160380712A1
• Filed: 09/07/2016
• Published: 12/29/2016
• Est. Priority Date: 08/11/2004
• Status: Abandoned Application

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Levy, Joseph S.
• Application Number:
  US15/258,243
• Publication Number:
  US 20160380712A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 7/02 Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas RAKE receivers H04B1/7115
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0421 utilizing implicit feedback, e.g. steered pilot signals
• CPC Class Codes: H04B 7/0443 utilizing "waterfilling" technique
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A transmitter generates and transmits a low rate signal to its intended receiver. Upon receiving the low rate signal, the intended receiver generates and transmits a channel sounding response (CSR), said CSR being a short burst having a predefined transmit format and carrying predetermined information. The transmitter then analyzes the CSR and determines uplink channel response, estimates downlink channel response, and determines appropriate transmit parameter settings based on the analysis and downlink response estimate. Adjustment of the transmit parameters can be made in either the MAC or PHY layer or in a combination of both. After adjusting its transmit parameters and modulating sub-carriers with user-data according to the determined transmit settings, the transmitter transmits the user-data to the receiver on a preferred portion of bandwidth. In a preferred embodiment, the transmitter also generates and transmits a transmit format control (TFC) signal containing the determined transmit parameter settings, including sub-carrier modulation information, to the receiver.

Claims

1-16. -16. (canceled)

17. A method for improving system performance in a Multiple-Input, Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system comprising:

(a) monitoring CSR signals transmitted between a transmitter and a receiver;

(b) assessing channel conditions of a communication link between the transmitter and the receiver;

(c) maintaining a history of said channel conditions;

(d) adjusting transmit parameters based on the channel history; and

(e) communicating with the transmitter and receiver utilizing the adjusted transmit parameters.