Description: 基于matlab实现OFDM系统
包括信号时域频域仿真 误码率分析-Matlab-based system, including the realization of OFDM signal frequency domain simulation BER analysis Platform: |
Size: 1871 |
Author:范进 |
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Description: WLAN仿真－发送机
wlan No Comments
设置完系统参数后，开始产生发送数据。
1. 产生随机的发送bit（tx_bits），这里不考虑信道编码。
2. QAM映射
3. 将数据映射到不同载波，形成OFDM符号
4. 产生pilot，并将pilot插入OFDM符号中
5. 加入dc和guard子载波
6. 进行ifft，将频域信号变到时域，并加入循环前缀
7. 对信号进行overlap window
8. 在时域产生short preamble
9. 在时域产生long preamble
10. 将preamble和数据符号组成packet
11. 升采样
得到信道传输的数据Tx_signal_up
具体程序见附件 wlan_transmitter.m-WLAN Simulation- wlan No Comments transmitter system parameters set finished, the beginning to have to send data. 1. Have sent random bit (tx_bits), here does not consider channel coding. 2. QAM mapping 3. The data is mapped to a different carrier to form OFDM symbols 4. Have a pilot, and pilot inserted OFDM symbols 5. Adding dc and guard subcarriers 6. To carry out ifft, will change the frequency domain signal to time domain, and add cyclic prefix 7. the signals overlap window8. In the time domain have a short preamble9. In the time domain have a long preamble10. the preamble and data symbols packet11. or sampling received data transmission channel Tx_signal_up specific procedures see Annex wlan_transmitter.m Platform: |
Size: 1024 |
Author:福东方 |
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Description: 此函数利用LS算法对OFDM系统进行频域信道估计-This function use LS algorithm to OFDM systems in frequency domain channel estimation Platform: |
Size: 3072 |
Author:李世杰 |
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Description: 单波频域均衡(SC-FDE)和多载波正交频分复用(OFDM)是数字通信中用于克服多径衰落的两种技术。本文通过理论推导对这两种技术在高斯白噪声通信信道中的误码性能进行了比较,利用高斯分布尾部概率的数值变化
特性.-Single-wave frequency domain equalization (SC-FDE) and multi-carrier orthogonal frequency division multiplexing (OFDM) digital communication to overcome multipath fading of the two technologies. In this paper, theoretical analysis of these two Gaussian white noise in communication channel bit error performance is compared, using Gaussian tail probability and the change of properties. Platform: |
Size: 389120 |
Author:李昊男 |
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Description: 构建OFDM调制的数字电视信号DVB-T，得到其时域、频谱图，并对其上变频，模拟其发射！-Construction of OFDM modulation digital television signals DVB-T, by the time domain, frequency spectrum, and its up-conversion, analog of its launch! Platform: |
Size: 1024 |
Author:linve |
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Description: The code introduces postcoding technique in ofdm system that results in a much less complex mechanism and provide similar result as are obtained with precoded system. In this technique the coding part is done after the ifft block that is initially the data is converted to frequency domain n then coding is introduced. Platform: |
Size: 1024 |
Author:adi |
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Description: 多天线正交频分复用(MIMO-OFDM,Multiple-Input and Multiple-Output Orthogonal Frequency Division Multiplex)系统中,精确的符号定时同步可使接收端解调数据时消除载波频率偏移和符号间干扰。而由于MIMO空间信道复杂度较高,使得单天线OFDM系统的同步方法不能直接应用于MIMO-OFDM系统中。提出的两步同步方法首先利用时域导频作为第一步同步进行粗同步,然后利用循环交织前缀作为第二步同步对每一个MIMO-OFDM符号进行同步偏差调整。需要指出的是,两次同步过程均可以产生尖锐的相关峰,使得同步精度大为提高。-Accurate timing synchronization of symbol is important for MIMO-OFDM system,and it can eliminate the integral frequency shift of carrier and intersymbol interference.Two-step timing synchronization method is proposed in this thesis.First,the time-domain pilot is employed to obtain coarse timing synchronization,then the interleaved cyclic prefix and maximum likelihood estimation method are adopted to adjust the synchronization difference,through which the correlational characteristic of that window could be ... Platform: |
Size: 807936 |
Author:王睿 |
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Description: 由MATLAB程序产生2Gbi/s的基带OFDM信号先将2^15-1个伪随机序列映射到256个进行4QAM编码调制的子载波上，编码后的OFDM符号再经过IFFT变换将其转换为时域波形，接着添加6.4ns的循环前缀（CP），产生的数据波形再装载到Tektronix任意波形发生器（AWG）中，产生2Gbit/s的基带OFDM信号。基带OFDM信号频谱示意图如图3所示。其中包括256个OFDM子载波256个子载波中200个子信道用来传送数据信号，27个高频和28个低频子信道为了过采样的需要置0，OFDM频谱中最中间的那个子信道由于基带信号的直流成分大也被置0。-Generated by the MATLAB program 2Gbi/s baseband OFDM signal the first 2 ^ 15-1 pseudo-random sequence is mapped to 256 for 4QAM code modulation subcarriers, OFDM symbol after the re-encoded after IFFT transformation to convert it too domain waveform, and then add 6.4ns the cyclic prefix (CP), the data generated by Tektronix waveform and then loaded into the arbitrary waveform generator (AWG), resulting in 2Gbit/s baseband OFDM signal. Schematic diagram of the baseband OFDM signal spectrum shown in Figure 3. Including 256 sub-carrier OFDM subcarriers 256, 200 subchannels used to transmit data signals, 27 high and 28 low-frequency sub-channel over-sampling of the need to set 0, OFDM spectrum in the most middle of the baseband sub-channel as large DC component signal is also set to 0. Platform: |
Size: 220160 |
Author:QQ |
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Description: This source code describes the OFDM transmitted waveform at the transmitter both in frequency as well as time domain
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Size: 1024 |
Author:neelam |
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Description: The overall objective for LTE is to provide an extremely high performance radio-access technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the -The overall objective for LTE is to provide an extremely high performance radio-access technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the Platform: |
Size: 3072 |
Author:SREENESH.T.K |
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Description: mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the - mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the Platform: |
Size: 1024 |
Author:SREENESH.T.K |
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Description: Technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the -Technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the Platform: |
Size: 1024 |
Author:SREENESH.T.K |
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Description: Extremely high performance radio-access technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the -Extremely high performance radio-access technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. OFDM/OFDMA technology is introduced for the LTE downlink, supporting very high data rates of up to 300Mbps while Single-Carrier FDMA (SC-FDMA) is used in the uplink with data rates of 80Mbps possible. Additionally, LTE supports operation both in paired and unpaired spectrum (FDD and TDD) using channel bandwidths of approximately 1.4MHz up to 20MHz. The frequency domain scheduling can be done in OFDMA. One of the main challenges in OFDMA is the high peak-to-average radio of the transmitted signal, which requires linearity in the transmitter. The linear amplifiers have low efficiency therefore, OFDMA is not an optimized solution for a mobile uplink where the Platform: |
Size: 1024 |
Author:SREENESH.T.K |
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Description: 基于MATLAB的OFDM原理仿真程序，含时域和频域-OFDM principles based on MATLAB simulation program, including time domain and frequency domain Platform: |
Size: 1024 |
Author:gujuhui |
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Description: Channel estimation techniques for OFDM systems based on a pilot arrangement are investigated. Channel estimation based on a comb type pilot arrangement is studied through different algorithms for both estimating the channel at pilot frequencies and interpolating the channel. Channel estimation at pilot frequencies is based on LS and LMS methods while channel interpolation is done using linear interpolation, second order interpolation, low-pass interpolation, spline cubic interpolation, and time domain interpolation. Time-domain interpolation is obtained by passing to the time domain by means of IDFT (inverse discrete Fourier transform), zero padding and going back to the frequency domain by DFT (discrete Fourier transform). In addition, channel estimation based on a block type pilot arrangement is performed by sending pilots in every sub-channel and using this estimation for a Platform: |
Size: 3072 |
Author:MUHAMMAD SHAKIL |
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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 |
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Description: 非常好的OFDM系统的仿真，关于频域均衡和循环前缀-Very good simulation of OFDM systems, on frequency domain equalization and cyclic prefix Platform: |
Size: 9216 |
Author:邱念庭 |
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Search - ofdm frequency domain