Pilot frequency transmission and channel estimation method for bidirectional orthogonal frequency division multiplexing (OFDM) system
A technology of frequency division multiplexing and two-way orthogonality, applied in the direction of multi-frequency code system, baseband system components, etc., can solve the problems of reduced data transmission efficiency, low channel estimation accuracy, multiple sub-carriers, etc., and achieve improved data transmission efficiency , Channel estimation accuracy improvement, the effect of improving accuracy
Inactive Publication Date: 2011-11-23
ZHEJIANG WANLI UNIV
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[0005] First, pilots and data adopt an orthogonal multiplexing method. For a system with K subcarriers, if pilots are placed in n subcarrier positions, the sender and receiver can only use the remaining K-2n subcarrier positions to place data. In this way, in order to obtain higher channel estimation accuracy, it is usually necessary to insert more pilots, which means that more subcarriers will be occupied, resulting in a greatly reduced data transmission efficiency
[0006] Second, when the signal transmitter and receiver perform channel estimation, they only perform channel estimation based on the pilot information of the other party, and the accuracy of channel estimation is low.
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[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0025] The present invention provides a kind of pilot frequency transmission and channel estimation method for two-way OFDM system, and it comprises the following steps:
[0026] (1) Both the sender and receiver of the signal perform normalized Fourier transform on their respective data blocks containing the pilot signal and the sent data, and add a cyclic prefix and send it to the relay device at the same time;
[0027] Such as figure 1 , the two sides of the signal transmitter and receiver are terminal A and terminal B, the relay device is the relay terminal R, and the nth subcarrier symbol in the OFDM block sent by A and B at the tth moment is respectively s A，t (n), s B，t (n), n=1, 2, . . . , N. Each OFDM block contains N symbols, among which K are pilot symbols and N-K are data symbols.
[0028] When sending, the sending and ...
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The invention provides a pilot frequency transmission and channel estimation method for a bidirectional OFDM system, wherein in the invention, a pilot frequency and data utilize a non-orthogonal method, and the remainder K-n sub carrier positions can be used for placing data, thereby increasing the transmission efficiency. In the invention, a secondary channel estimation method is utilized, comprising the steps of: firstly performing a channel estimation of the first time according to the pilot frequency information of an opposite party and self sending data to obtain an initial channel estimated value, simultaneously obtaining the initial estimation of the sending data of the opposite party by the channel estimated value; and then performing an estimation of the second time according to the initial channel estimated value, the initial estimation of the sending of the opposite party and the self sending data, thus the estimation precision can be increased.
Description
Technical field: [0001] The invention relates to the technical field of wireless communication, in particular to a method for pilot frequency transmission and channel estimation used in a two-way orthogonal frequency division multiplexing system. Background technique [0002] In recent years, users' demand for high-speed wireless data services such as video telephony and mobile Internet has been increasing, which puts forward higher requirements for the coverage and bandwidth of wireless networks. However, due to the rapid attenuation of radio wave signals in the air with the increase of transmission distance, the coverage of wireless networks is limited to a certain extent under the constraints of transmission power. In order to solve the above problems, by introducing relay base stations in the network to help users forward signals, the power consumption of transmitting terminals can be reduced to a certain extent, and the transmission distance can be increased. Among them...
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IPC IPC(8): H04L27/26H04L25/02
Inventor 方朝曦
Owner ZHEJIANG WANLI UNIV