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

Signal constellations for multi-carrier systems

一种多载波、星座的技术，应用在多载波系统、调相载波系统、调频载波系统等方向，能够解决高误差基底、差性能等问题

Inactive Publication Date: 2009-12-23
SPYDER NAVIGATIONS L L C
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] The constellation designed for the ideal CSI case is no longer optimal when there is channel estimation error due to the above effects
Using this prior art constellation usually results in poor performance and high error floor, especially in fast fading environments and long delay spread

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
  • Signal constellations for multi-carrier systems
  • Signal constellations for multi-carrier systems
  • Signal constellations for multi-carrier systems

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0040] The present invention can be implemented in a transmitter or receiver, or both, of a multi-carrier system, such as an OFDM system or a multi-carrier code division multiple access (MC-CDMA) system, using software, hardware, or a combination of software and hardware. It is assumed that the software is implemented as a look-up table, algorithm, or other program code that defines signal constellation points and accesses it to map a signal to be transmitted to a signal constellation or to map received symbols from a signal constellation. The same signal constellation resides in one or both of transmitter 22a and receiver 22b, but need not be implemented in the same format (look-up table, algorithm, etc.).

[0041] Figure 1A The block diagram of an OFDM modem 20 showing N subcarriers, also shown here as a multi-carrier transceiver or multi-carrier system, is merely an example of a multi-carrier modem that might use the invention to good effect. At the transmitter 22a, a modu...

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

A signal constellation for a wired or wireless multi-carrier communication system, such as a system using OFDM or MC-CDMA, with mutually separated various points. Preferably, the constellation points are arranged on concentric circles, with or without a point at the origin, wherein adjacent circles are rotated to maximize the angular distance between points on adjacent circles. The receiver uses pilot symbols inserted into the transmitted signal to estimate the channel of the multi-carrier system. Different constellations represent optimal performance for different signal-to-noise ratios and for different numbers of taps used to estimate the channel, especially in fast fading environments where the number of pilots in each OFDM or MC-CDMA symbol is less than the number of channel taps middle.

Description

technical field [0001] The present invention relates generally to signal constellations for multi-carrier digital communications and standards for designing such signal constellations. The invention particularly relates to signal constellations based on maximizing the minimum Kullback-Leibler distance between statistical distributions, which can be used in, but not necessarily limited to, fast fading environments and high SNR environments. Background technique [0002] Frequency Division Multiplexing (FDM) is a technique for simultaneously transmitting multiple signals over a single transmission path such as a wired or wireless system. Each signal travels within its own unique frequency range (called a carrier, subcarrier, or subchannel), which is modulated by data (text, sound, video, etc.). Each signal is a sequence of bits or symbols mapped from a signal constellation (in the case of a transmitted signal) or mapped to a signal constellation (in the case of a received sig...

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): H04L27/04H04L27/12H04L27/20H04L5/02H04L27/26H04L27/34
CPCH04L27/0008H04L5/0007H04L25/0226H04L5/0021H04L27/3405H04L27/3455H04L25/022H04L5/0048H04L27/26H04L5/02H04L27/34
Inventor 莫哈梅德·杰伯·博兰普拉博德·瓦施奈伊若尔马·利勒贝格
Owner SPYDER NAVIGATIONS L L C