Unlock instant, AI-driven research and patent intelligence for your innovation.

Mimo system with multiple spatial multiplexing modes

A technology of time division duplex, communication system, applied in the field of communication, can solve problems such as performance degradation and error

Active Publication Date: 2013-08-14
QUALCOMM INC
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If the obtained reciprocity of the channel response of one link is used for spatial processing on the other link, any difference in the frequency responses of the transmit and receive chains will represent an error which, if not determined or resolved, is May degrade performance

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Mimo system with multiple spatial multiplexing modes
  • Mimo system with multiple spatial multiplexing modes
  • Mimo system with multiple spatial multiplexing modes

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0021] The calibration techniques described herein can be used in various wireless communication systems. Furthermore, these techniques may be used for single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, single-input multiple-output (SIMO) systems, and multiple-input multiple-output (MIMO) systems.

[0022] A MIMO system employs multiple (N T ) transmit antennas and multiple (N R ) receiving antennas for data transmission. by this N T transmit antennas and N R The MIMO channel formed by receiving antennas can be decomposed into N S independent channels, where N R ≤min{N T , N R}. this N S Each of the independent channels is also called a spatial channel of the MIMO channel and corresponds to a dimension. MIMO systems can provide improved performance (eg, increased transmission capacity) if the extra dimension created by the multiple transmit and receive antennas is exploited. This usually requires an accurate estimate of the chann...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

Techniques are described to calibrate the downlink and uplink channels to account for differences in the frequency responses of the transmit and receive chains at an access point and a user terminal. In one method, pilots are transmitted on the downlink and uplink channels and used to derive estimates of the downlink and uplink channel responses, respectively. Correction factors for the access point and correction factors for the user terminal are determined based on (e.g., by performing matrix-ratio computation or minimum mean square error (MMSE) computation on) the downlink and uplink channel response estimates. The correction factors for the access point and the correction factors for the user terminal are used to obtain a calibrated downlink channel and a calibrated uplink channel, which are transpose of one another. The calibration may be performed in real time based on over-the-air transmission.

Description

[0001] The patent application of the present invention is the international application number PCT / US2006 / 003203, the international application date is January 27, 2006, the application number entering the Chinese national phase is 200680006710.9, and the name is "Channel Calibration for Time Division Duplex Communication System" The divisional application of the invention patent application. technical field [0002] The present invention relates generally to communications, and more particularly to techniques for calibrating downlink and uplink channel responses in time division duplex (TDD) communication systems. Background technique [0003] In a wireless communication system, data transmission between an access point and a user terminal is performed on a wireless channel. Depending on the system design, downlink and uplink may use the same or different frequency bands. The downlink (or forward link) refers to the communication link from the access points to the user ter...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H04L1/06H04L27/26H04L12/56H04L1/16H04L25/03H04L5/14H04B7/005H04J99/00H04B7/04H04B7/08H04B7/06H04B17/00H04L25/02H04L1/08H04L12/28H04L1/00
CPCH04L25/0244H04L1/0017H04L2001/0093H04L27/261H04L1/0001H04B7/0615H04W16/28H04L1/0059H04L1/0003H04B7/0619H04L1/0618H04L1/06H04B17/0062H04L1/0061H04L27/2601H04W52/42H04L25/0224H04L1/0009H04L25/0204H04W52/50H04B7/0697H04L1/0071H04L25/0226H04L25/03343H04L1/08H04L27/2602H04L1/16H04L5/1469H04B7/0421H04L27/2647H04L25/0242H04L1/0068H04L2025/03426H04B7/0854H04L2025/03414H04B7/0669H04B17/21H04J3/02H04L5/22H04L25/0256
Inventor M·S·华莱仕J·W·凯特彻姆J·R·沃尔顿S·J·霍华德
Owner QUALCOMM INC