Location:
Search - OFDM symbols
Search list
Description: ＯＦＤＭ程序 波形如下
子载波数 128
％ 位数/ 符号 2
％ 符号数/ 载波 100
％ 训练符号数 0
％ 循环前缀长度 8 (1/16)*T
％ 调制方式 4-QAM
％ 多径信道数 3
％IFFT Size 128
％ 信道最大时延 2-OFDM waveform procedures following subcarriers median number of 128% / 2% Symbol Symbol / Carrier 100% Training a few symbols 0% cyclic prefix length 8 (1 / 16) * T% modulation 4-QAM% multi-path channel number 3% IFFT Size 128% maximum delay Channel 2
Platform: |
Size: 3857 |
Author: 唐成玉 |
Hits:
Description: This project aim was to build wireless software modem for data communication
between two computers using an acoustic interface in the voice frequency range (20Hz–
20,000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz –
20,000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz –
16,000Hz). The test files used as information files were text files.
This goal was attained both in an incoherent scheme and in a coherent scheme.
Build under Matlab code, our modem uses OFDM (orthogonal frequency division
multiplexing) modulation, synchronization by LMS sequence, channel estimation (no
equalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of
2 or 4. To optimize the probability of error, these symbols were mapped using Gray
mapping.
Report
Platform: |
Size: 559541 |
Author: buyop |
Hits:
Description: ofdm信道特性
Channel transmission simulator
Channel transmission simulator
％
％ inputs:
％ sig2 - noise variance
％ Mt - number of Tx antennas
％ Mr - number of Rx antennas
％ x - vector of complex input symbols (for MIMO, this is a matrix, where each column
％ is the value of the antenna outputs at a single time instance)
％ H - frequency selective channel - represented in block-Toeplitz form for MIMO transmission
％ N - number of symbols transmitted in OFDM frame
％
％ outputs:
％ y - vector of channel outputs (matrix for MIMO again, just like x matrix)
％ create noise vector sequence (each row is a different antenna, each column is a
％ different time index) note: noise is spatially and temporally white
Platform: |
Size: 812 |
Author: sunxu |
Hits:
Description: 加循环前后缀和升采样程序，插入循环前后缀是将每个OFDM符号的前32个数据放到符号尾部，将每个OFDM符号的后32个数据放到符号头部，升采样是通过中间插零的方式实现-Cycle before adding the suffix and lift sampling program, insert the loop before the suffix is ??the first of each OFDM symbol data into the symbolic end of 32, after each OFDM symbol data into the symbols of 32 head or through the middle of the sampling way to achieve zero insertion
Platform: |
Size: 1024 |
Author: 罗速 |
Hits:
Description: a program to divide a sequence to subsequences. Helpful for the OFDM simulations:
Function to divide the input sequence to sub sequences
s2ss - Function
1. (cd) Input the data
2. (hl) Hadamard matrix length
3. Outpot of the function is an array st(m,outs).
m is the number of the produced symbols
outs are the new sequences where their length is 0.75*hl where hl is the
Hadamard length.
Montadar Abas Taher
12/03/20-a program to divide a sequence to subsequences. Helpful for the OFDM simulations:
Function to divide the input sequence to sub sequences
s2ss - Function
1. (cd) Input the data
2. (hl) Hadamard matrix length
3. Outpot of the function is an array st(m,outs).
m is the number of the produced symbols
outs are the new sequences where their length is 0.75*hl where hl is the
Hadamard length.
Montadar Abas Taher
12/03/2011
Platform: |
Size: 2048 |
Author: Montadar |
Hits:
Description: dct precoded SLM method for PAPR reduction
High Peak to Average Power Ratio (PAPR) is still a
most important challenge in Orthogonal Frequency Division
Multiplexing (OFDM) system. In this paper, we propose a
Discrete Cosine Transform (DCT) precoding based SLM
technique for PAPR reduction in OFDM systems. This
technique is based on precoding the constellation symbols with
DCT precoder after the multiplication of phase rotation factor
and before the Inverse Fast Fourier Transform (IFFT) in
SLM-OFDM System.
Platform: |
Size: 234496 |
Author: MAHESH |
Hits:
Description: Abstract—In this paper, we study the joint estimation of inphase
and quadrature-phase (I/Q) imbalance, carrier frequency
offset (CFO), and channel response for multiple-input multipleoutput
(MIMO) orthogonal frequency division multiplexing
(OFDM) systems using training sequences. A new concept called
channel residual energy (CRE) is introduced. We show that by
minimizing the CRE, we can jointly estimate the I/Q imbalance
and CFO without knowing the channel response. The proposed
method needs only one OFDM block for training and the training
symbols can be arbitrary. Moreover when the training block
consists of two repeated sequences, a low complexity two-step
approach is proposed to solve the joint estimation problem.
Simulation results show that the mean-squared error (MSE) of
the proposed method is close to the Cramer-Rao bound (CRB).
Index Terms—MIMO OFDM, CFO, I/Q imbalance, channel
estimation.
Platform: |
Size: 551936 |
Author: santhu |
Hits:
Description: Abstract—In this paper, we study the joint estimation of inphase
and quadrature-phase (I/Q) imbalance, carrier frequency
offset (CFO), and channel response for multiple-input multipleoutput
(MIMO) orthogonal frequency division multiplexing
(OFDM) systems using training sequences. A new concept called
channel residual energy (CRE) is introduced. We show that by
minimizing the CRE, we can jointly estimate the I/Q imbalance
and CFO without knowing the channel response. The proposed
method needs only one OFDM block for training and the training
symbols can be arbitrary. Moreover when the training block
consists of two repeated sequences, a low complexity two-step
approach is proposed to solve the joint estimation problem.
Simulation results show that the mean-squared error (MSE) of
the proposed method is close to the Cramer-Rao bound (CRB).
Index Terms—MIMO OFDM, CFO, I/Q imbalance, channel
estimation.
Platform: |
Size: 277504 |
Author: santhu |
Hits:
Description: 在OFDM系统下，在SIMULINK的仿真条件下，对数字信号符号加循环前缀的程序代码。-In an OFDM system, in the the SIMULINK simulation conditions, the program of the digital signal symbols plus the cyclic prefix code.
Platform: |
Size: 1024 |
Author: duyamei |
Hits:
Description: Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation method with the initial idea to overcome multipath fading in a wireless environment. Multipath effect causes an unacceptable symbol in multiple copies but with a different time causing inter symbol interference (ISI) between the symbols in the receiver.
Platform: |
Size: 1024 |
Author: oktavia |
Hits:
Description: A major challenge to MIMO-OFDM systems is how to obtain the channel state in-
formation accurately and promptly for coherent detection of information symbols and
channel synchronization.,A major challenge to MIMO-OFDM systems is how to obtain the channel state in-
formation accurately and promptly for coherent detection of information symbols and
channel synchronization.
Platform: |
Size: 581632 |
Author: Nirupa |
Hits:
Description: A major challenge to MIMO-OFDM systems is how to obtain the channel state in-
formation accurately and promptly for coherent detection of information symbols and
channel synchronization.,A major challenge to MIMO-OFDM systems is how to obtain the channel state in-
formation accurately and promptly for coherent detection of information symbols and
channel synchronization.
Platform: |
Size: 1074176 |
Author: Nirupa |
Hits:
Description: 在OFDM系统中，利用在两个连续的OFDM符号中导频信号之间的相位差，进行基于导频的频域CFO估计技术。-In OFDM systems, the use of two consecutive OFDM symbols pilot phase difference between the signals, frequency domain based pilot CFO estimation techniques.
Platform: |
Size: 1024 |
Author: 耿晓文 |
Hits:
Description: In an OFDM system, the transmitter modulates the message bit sequence into PSK/QAM
symbols, performs IFFT on the symbols to convert them into time-domain signals, and sends
them out through a (wireless) channel. The received signal is usually distorted by the channel
characteristics.
Platform: |
Size: 49152 |
Author: shaik |
Hits:
Description: ofdm 传输与接受的各项例子
-OFDM Receiver
1. Initalize the USRP setting the RX parameters and moving the LO outside the transmission band.
2. Generate random data bits (PN Sequence) (125 bits)
3. Use the Van De Beek algorithm to detect the cyclic prefix locatoins for synchronization and estimate frequency offset
4. Remove the cyclic prefix
5. Remove the frequency offset the incoming signal
6. Compute the FFT convertin the time domain OFDM symbol to the frequency domain
7. Separate data bits, reference bits, and remove zero padding
8.Compute equalization coefficients using a linear fit for both I and Q based on reference symbols
9. Apply the equalization to the data symbols
10. Convert data symbol mapping back to data bits
Platform: |
Size: 460800 |
Author: kai |
Hits:
Description: OFDM系统仿真，非常完整，适合于学习OFDM的同学。包括 串并变换子载波调制
OFDM的IDFT/DFT实现保护间隔与循环前缀 基于OFDM的802.11a系统 802.11a的帧结构 802.11a OFDM物理层编码过程 系统参数训练符号 Signal域
Data域的扰码及解扰卷积编码器和Viterbi译码交织子载波调制与解调
IEEE 802.11a系统的仿真
-OFDM system simulation, very complete, suitable for learning OFDM students. Including string and transform subcarrier modulation
OFDM IDFT/DFT implementation protection interval and cyclic prefix 802.11a system based on OFDM 802.11a frame structure 802.11a OFDM physical layer coding process system parameters training symbols Signal domain
Data domain scrambling and descrambling convolutional encoders and Viterbi decoding interleaved subcarrier modulation and demodulation
Simulation of IEEE 802.11a system
Platform: |
Size: 7168 |
Author: 徐兵政 |
Hits:
Description: 实现OFDM中符号的定时同步以及频偏估计(Timing synchronization and frequency offset estimation of symbols in OFDM)
Platform: |
Size: 1024 |
Author: esmee_wan
|
Hits:
Description: 这是一个基于空时分组编码的 MIMO_OFDM 通信系统的仿真设计。此系统包括 QPSK 调制解调， IFFT 调制，空时编解码，基于训练符号的信道估计等通信模块，包含这些模块的 m 文件。(This is a simulation design of a MIMO_OFDM communication system based on space-time block coding.This system includes QPSK modulation and demodulation, IFFT modulation, space-time codec, channel estimation based on training symbols and other communication modules, including the m files of these modules.)
Platform: |
Size: 3072 |
Author: 强王 |
Hits:
Description: ofdm papr reduction 1000 symbols
Platform: |
Size: 2401 |
Author: CVR16B81A0416 |
Hits:
Description: Different from existing OFDM receivers
that first estimate channel state information (CSI) explicitly and
then detect/recover the transmitted symbols using the estimated
CSI,
Platform: |
Size: 509516 |
Author: shirbhatearchana72018@gmail.com |
Hits: