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Apparatus and method for estimating channel in ofdm/ofdma based wireless communication system

wireless communication technology, applied in the field of appratus and method for estimating a channel in a wireless communication system, can solve problems such as distortion of transmission signals, and achieve the effect of increasing the accuracy of channel estimation

Inactive Publication Date: 2010-02-04
SEAH NETWORKS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0024]Accordingly, the present invention has an advantage in that it can increase the accuracy of channel estimation by employing a preamble channel estimation value of a preamble and pilot channel estimation values of pilots transmitted from a plurality of transmitting antennas in a MIMO communication system.
[0025]Furthermore, the present invention can estimate a channel by employing a pilot channel estimation value of a downlink PUSC channel mode included in received signals received by a plurality of receiving antennas.
[0026]Further, the present invention accuracy of channel estimation by estimating a channel through interpolation of a preamble channel estimation value and a pilot channel estimation value.
[0027]Furthermore, the present invention accuracy of channel estimation by carrying out an operation on a channel estimated through interpolation between a pilot channel estimation value and a preamble channel estimation value.
[0028]Further, the present invention channel estimation by estimating a channel by setting weight values differently according to pilot patterns.

Problems solved by technology

A wireless packet channel has time selective fading where a channel is varied according to time due to this characteristic and frequency selective fading having frequency components of different sizes and phases due to delay reception through multiple paths having a variety of lengths, resulting in the distortion of a transmission signal.

Method used

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  • Apparatus and method for estimating channel in ofdm/ofdma based wireless communication system
  • Apparatus and method for estimating channel in ofdm/ofdma based wireless communication system
  • Apparatus and method for estimating channel in ofdm/ofdma based wireless communication system

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first embodiment

[0077]FIG. 8 is a construction block diagram regarding the channel estimation apparatus according to the present invention.

[0078]Referring to FIG. 8, the channel estimation apparatus of the present invention includes first and second FFT units 110 and 150, first and third channel operation units 120 and 160, first and third channel estimation units 130 and 170, and second and fourth channel estimation units 140 and 180.

[0079]The first and second FFT units 110 and 150 transform received signals with baseband (first and second received signals), which are received through first and second receiving antennas of a communication mobile station, respectively, into signals of frequency domain by performing FFT on the received signals. The baseband signals received through the first and second receiving antennas may be transformed into the signals of frequency domain through the first and second FFT units, respectively, but transformed into the signals of the frequency domain through one FF...

second embodiment

[0124]FIG. 11 is a construction block diagram with respect to a channel estimation apparatus according to the present invention.

[0125]Referring to FIG. 11, the channel estimation apparatus in accordance with the present invention includes first and second FFT units 210 and 250, first and third channel estimation units 220 and 260, first and third channel operation units 230 and 270, and second and fourth channel estimation units 240 and 280.

[0126]When comparing the first channel estimation unit 220 and the first channel estimation unit 130 illustrated in FIG. 8, the first channel estimation unit 130 illustrated in FIG. 8 estimates a channel by employing a pilot channel estimation value improved based on a preamble channel estimation value, whereas the first channel estimation unit 220 illustrated in FIG. 11 estimates a channel by employing pilot channel estimation values of pilots transmitted from the first transmitting antenna.

[0127]The first and second FFT units 210 and 250 and th...

third embodiment

[0148]FIG. 13 is a construction block diagram regarding a channel estimation apparatus according to the present invention.

[0149]Referring to FIG. 13, the channel estimation apparatus in accordance with the present invention includes first and second FFT units 310 and 340, and first, second, third, and fourth channel estimation units 320, 330, 350, and 360.

[0150]A channel is estimated by employing a preamble channel estimation value and a pilot channel estimation value in the above embodiments, whereas in the third embodiment of the present invention illustrated in FIG. 13, a channel is estimated by employing only pilot channel estimation values respectively transmitted from the transmitting antennas.

[0151]The first and second FFT units 310 and 340 perform the same functions as those of the first and second FFT units illustrated in FIG. 8 and, therefore, detailed description on the first and second FFT units is omitted.

[0152]The first, second, third, and fourth channel estimation uni...

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PUM

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Abstract

A channel estimation apparatus of the present invention includes a preamble channel operation unit for carrying out an operation on pilot channel estimation values of pilots, which are transmitted from a transmitting antenna that transmits a preamble, as an improved pilot channel estimation value by employing a preamble channel estimation value based on a preamble included in received signals respectively received by a plurality of receiving antennas, a first channel estimation unit for estimating a channel for each of the receiving antennas through interpolation of a symbol axis and a frequency axis employing the improved pilot channel estimation value, and a second channel estimation unit for estimating a channel for each of the receiving antennas through interpolation of a symbol axis and a frequency axis employing pilot channel estimation values of pilots transmitted from the same transmitting antenna, of pilots transmitted from a transmitting antenna that does not transmit the preamble, of a plurality of transmitting antennas.

Description

TECHNICAL FIELD[0001]The present invention relates to an apparatus and method for estimating a channel in a wireless communication system and, more particularly, to an apparatus and method for estimating a channel in a Multiple Input Multiple Output (MIMO) wireless communication system in which IEEE 802.16d / e, WiBro, and WiMAX standard specifications are used and Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiplexing Access (OFDMA) is supported.BACKGROUND ART[0002]Mobile wireless channel environment includes a multi-path characteristic between a base station and a mobile station due to radio wave obstacles, which are distributed all around and have various sizes and materials, and also has a time-variable characteristic of a received signal since the mobile station or radio wave obstacles are moved.[0003]A multi-path between the base station and the mobile station has paths of different lengths, and has a delay spread characteristic in which ...

Claims

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Application Information

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IPC IPC(8): H04L27/28
CPCH04L5/0042H04L5/0048H04L25/0204H04L25/022H04L27/2675H04L27/2657H04L27/2662H04L27/2613H04L25/0232
Inventor KIM, BYUNG-CHULLI, ZHENG ZIJI, SANG-BAE
Owner SEAH NETWORKS CO LTD
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