Method and device for acquiring channel information

A channel information and channel technology, applied in the field of obtaining channel information, can solve the problems of occupying time-frequency resources, increasing the computational burden of the receiving end, etc., to achieve the effect of reducing processing complexity

Inactive Publication Date: 2009-11-04
HUAWEI TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] The purpose of the embodiments of the present invention is to provide a method and device for obtaining channel information, so as to solve the proble

Method used

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  • Method and device for acquiring channel information
  • Method and device for acquiring channel information
  • Method and device for acquiring channel information

Examples

Experimental program
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Example Embodiment

[0035] Embodiment 1. In this embodiment, multiple terminals use CDM (CODE DIVISION MULTIPLEXING, code division multiplexing) to multiplex uplink pilots, and the uplink pilots of each terminal are orthogonal to each other. The processing procedure of the base station transmitting data in this embodiment is as follows: figure 2 As shown, the specific processing process is as follows:

[0036] The base station first performs coding modulation and pre-equalization processing on the signal to be transmitted, inserts a downlink pilot in the frequency domain of the processed signal, and then performs OFDM (orthogonal frequency division multiplexing) modulation on the signal, and adds CP After (Cyclic Prefix), it is transmitted through the physical transmission channel.

[0037] The process of receiving and processing signals by the terminal in this embodiment is as follows: image 3 As shown, the specific processing process is as follows:

[0038] The data transmitted by the above-menti...

Example Embodiment

[0107] Embodiment 2. This embodiment is mainly to reduce the destruction of pilot orthogonality due to frequency selective fading. When the bandwidth is greater than the coherent bandwidth, different frequency points of the signal will show different fading characteristics after passing through the broadband wireless physical channel. Each part of the signal experiences different attenuation, resulting in frequency selective fading.

[0108] The processing procedure for estimating the uplink channel and the downlink channel provided by this embodiment is as follows:

[0109] 1. The base station generates a downlink pilot, performs Fourier transform processing on the downlink pilot, and then performs subcarrier mapping and IFFT transformation processing, and then transmits after OFDM modulation and CP addition.

[0110] 2. The downlink pilot sent by the above base station is received by the terminal. After de-CP and OFDM demodulation, the terminal multiplies the obtained downlink p...

Example Embodiment

[0113] Embodiment 3. This embodiment is mainly to reduce the damage to the pilot orthogonality caused by different uplink and downlink scrambling codes. The processing procedure for estimating the uplink channel and the downlink channel provided by this embodiment is as follows:

[0114] 1. The base station generates a downlink pilot, performs Fourier transform processing on the downlink pilot, and then performs subcarrier mapping and IFFT transformation processing. Then, after OFDM modulation, CP is added, and the downlink user scrambling code is used for scrambling, it is transmitted Get out.

[0115] 2. The downlink pilot sent by the above base station is received by the terminal, and the downlink pilot is descrambled, CP, OFDM demodulated, and then scrambled by the uplink user scrambling code, and then multiplied by an orthogonal code. , Superimpose with the uplink pilot frequency processed by Fourier transform to obtain the mixed pilot frequency, and the terminal transmits th...

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Abstract

The invention provides a method and a device for acquiring channel information. The method mainly comprises the following steps that: a transmitting terminal sends downlink pilot frequency information to a receiving terminal and receives a mixed pilot frequency returned by the receiving terminal, wherein the mixed pilot frequency is acquired by multiplying the received downlink pilot frequency by an orthogonal code and then superimposing the result with an uplink pilot frequency by the receiving terminal, and the orthogonal code only corresponds to the receiving terminal; and the transmitting terminal performs estimation on uplink channel information according to uplink pilot frequency information in the mixed pilot frequency, and performs estimation on downlink channel information of the receiving terminal according to the estimated uplink channel information and downlink pilot frequency and orthogonal code information in the mixed pilot frequency. By using the method and the device, the transmitting terminal can accurately acquire the uplink and downlink channel information under the condition of not increasing extra feedback signaling overhead.

Description

technical field [0001] The present invention relates to the field of wireless communication, in particular to a method and device for acquiring channel information. Background technique [0002] A schematic diagram of the transmission and reception process of a wireless communication system is shown in figure 1 shown. In a wireless communication system, the transmitted signal is affected by the physical transmission channel during transmission, and fading and distortion will occur. In order to recover the transmitted signal, the receiving end usually needs to estimate the physical transmission channel and eliminate the physical transmission channel through equalization processing. influence on the transmitted signal. The effect of the above equalization processing is affected by noise. For example, the zero-forcing equalizer will cause noise amplification in the case of a low signal-to-noise ratio, and the MMSE (Minimum Mean Square Error, minimum mean square error) equaliz...

Claims

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Application Information

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IPC IPC(8): H04L25/03H04L25/02H04B1/707
Inventor 孙铭扬杨云松常欣
Owner HUAWEI TECH CO LTD
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