DDR_interface

说明：  very important dtmf project

说明：  STM32F4 SPI 4线驱动RA8875 彩屏方案(stm32f4 driver ra8875 TFT lcd display)

瑞利衰落信道，是一种无线电信号传播环境的统计模型。这种模型假设信号通过无线信道之后，其信号幅度是随机的，即“衰落”，并且其包络服从瑞利分布。这一信道模型能够描述由电离层和对流层反射的短波信道，以及建筑物密集的城市环境。(Rayleigh fading channels, the statistical model of a radio signal propagation environment. This model assumes that after the signal through the radio channel, the signal amplitude is random, ie, the " fading" and the envelope of the Rayleigh distribution. This channel model is able to describe the HF channel reflected by the ionosphere and troposphere, as well as building a dense urban environment.)

一个关于语音电话的程序( About pronunciation telephone procedure )

PDA 电表IEC62056应用开发原程序代码,应该有较大参考价值,可以直接运行.(PDA IEC62056 CODE CAN RUN ,HAVE VERY MUCH VALUE TO IEC62056 DEVELOPER USE BY C#.)

说明：  根据卫星EIRP值、接收系统G/T值等参数仿真了卫星通信的上下行及总链路预算的matlab程序 及论文《卫星传输链路的计算与应用》(uplink and downlink margin budget)

本源码是本人工作之余码的，CC2540低功耗蓝牙的notify工作方式总结，这源码是很好的理解notify例子，代码中有注释，希望对大家有所帮助(The source code is my spare time, notify work CC2540 Bluetooth low energy summary, this source is well understood notify example, the code notes, we hope to help)

说明：  振铃芯片KA2410数据手册(Ringing chip KA2410 Data Sheet)

本论文以OFDM系统为基础，介绍了OFDM系统的基本原理，以及使用OFDM技术的优势所在，并且展望了今后的无线移动技术的发展前景。在简单介绍OFDM原理的同时，着重阐述了OFDM系统在不同信道环境和不不同实现方式下的误码性能。主要包括了OFDM系统在加性白高斯信道，在加性白高斯信道和多径干扰两种不同信道环境下系统的误码性能，其中后者还研究了系统在有保护间隔与无保护间隔的误码性能比较。在理论分析的基础 (This thesis is based on the OFDM system, the basic principle of the OFDM system, as well as the advantages of using OFDM technology, and future prospects for the development of future wireless and mobile technologies. OFDM principle in brief, focusing on the BER performance of OFDM systems under different channel conditions and different implementations. Including OFDM system in additive white Gaussian channel, additive white Gaussian channel and multipath interference of two different channel environment, the system BER performance, the latter of which also studied the system in a protected interval without guard interval BER performance comparison. The basis of theoretical analysis)

说明：  OPNET仿真教程，练习实例，供新手入门练习(OPNET Simulation course, practice examples, for beginners to practice)