qam modulation

pulse width modulation (Pulse Width Modulation). The pulse width of the pulse column is changed according to a certain law to adjust the output and waveform.Pam is the abbreviation of pulse amplitude modulation (pulse amplitude modulation). It is a modulation method that ch

I have been paying attention to audio effect recently, so I have reprinted several articles for learning. Basically, the pedal with a single effect is better than the integrated effect, because most of the effect sound in the market is "false ", many of the combined effects emphasize that they have dozens or even hundreds of effects, in fact, the basic effects (Distortion, Time Modulation, Reverb, Pitch Shift, Wah, etc.) listed below are arranged be

in the world's GHz engineering medical (ISM) frequency band and uses the Frequency Hopping (FHSS) technology ). The frequency hopping rate is 1600 times per second. A maximum of 79 1 MHz bandwidth channels can be obtained at a GHz center frequency. The Bluetooth device uses gfsk modulation. The transmission rate is 1 Mb/s. The actual effective rate is up to kb/s, and the transmission distance is 10 m. Voice Transmission uses Continuous Variable Slope

distance of Bluetooth 3.0 is 10 meters (about 32 feet), while that of Bluetooth 4.0 is up to 100 meters (about 328 feet ).Iv. Technical Features of BluetoothSimply put, Bluetooth is a short-range broadband radio technology and a global open standard for wireless voice and data transmission. It uses advanced technologies such as FHSS, TDMA, and CDMA to establish information transmission between multiple communication and information systems in a small scope.1. Main Technical Features of Bluetoot

; other high-frequency segments transmit downstream channel data, images, or high-speed data. ADSL access technology mainly uses DMT or CAP modulation methods. DMT is a discrete multi-frequency modulation. It divides all the frequencies into 256 sub-channels, and dynamically allocates the input data to them based on the instantaneous attenuation, group delay, and noise characteristics of the sub-channels. A

necessarily better than others. But after all, it is the lack of their own, need to fill up.The following attempts to illustrate the main interpretation of OFDM, with "easy to understand" as the first. "Little white", are you ready?Note: The following discussion, if not described, is assumed to be an ideal channel.Chapter One: OFDM on the time domainThe "O" of OFDM stands for "quadrature", so let's talk about orthogonal.First of all, in the simplest case, sin (t) and sin (2t) are orthogonal "pr

: Implement voltage controlled oscillator.Comm Sinks: This library provides modules for both the delivery and display of the communication system to make it easier to analyze.Triggered write to file module: writes data to files at the rising edge of the input signal.Enor Rate Calculation module: Calculates the error bit rate and the false sign ratio of the input signal.Source Code Coding Module Library: The source code is divided into two basic steps: source code and source decoding. The source

The SDK provides a simple terminal. It is simple enough for text output, but you may prefer different terminals like Tara. Now, we'll show you how to leverage the SDK terminal.tab to switch to stdio. Select Port USB UART and set the baud rate to 115200. This is a fixed hardware setting that is determined by the hardware platform, click Apply, and then click Run. You can monitor the progress download in the lower right corner(baudrate) The rate of the analog line signal, also called the

Cdma:code Division multiple Access The algorithm is as-I have recapped before modulation (modulation) (1) First 0 of the data into -1a = [1,-1,1], B = [1,1,-1] The advantage is that when demodulation, can be different from 0 and 1, and the demodulation error rate decreased. (2-1) A uses the first channel of Walsh Transform [1,1,1,1,1,1,1,1] (that is, its first basis, the first row of the matrix) to do

information (inferred)) Generally divided into: lossless compression and lossy compression There are many methods of compression coding, mainly divided into the following four categories: (1) pixel coding, (2) predictive coding, (3) Transformation coding; (4) Other methods. The so-called pixel coding means that each pixel is processed separately during encoding, regardless of the correlation between pixels. Several methods commonly used in pixel coding are: (1) Pulse code

1 Multimedia service drives the development of OFDM technology Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier digital modulation technology whose research history dates back to the mid 1960s, although the concept of OFDM has existed for a long time, but until recently, with the development of multimedia business, It is recognized that it is a good way of high-speed two-way wireless data communication. The technology, adopted by t

As one of the most hot access technology, wireless access technology by the operators, especially the new operators generally optimistic, the national radio Regulatory agencies also issued a specific frequency planning, it is evident that everyone to this technology attention and optimistic degree. 　　 According to the frequency planning of the national Radio Regulatory Agency, our frequency division is basically based on European standards. Within the limited 30MHz bandwidth, if the 1.75MHz band

The above section says analog signal analog carrier modulation, this section says the following analog signal digital carrier code. Digital transmission of analog signals The analog signal is sampled-quantified-encoded into a digital signal into the channel transmission Sampling: processing a continuous signal over time into discrete signals in time It should be noted that the Neiguist sampling theorem, that is, the sampling frequency is not less than

Tags: class blog http tar ext comSource: http://blog.csdn.net/kk185800961/article/details/12350715 Reprint Please specify the sourceXML instance file: XML version="1.0" encoding="Utf-8" ?> Root > Frame > Item > ID > 0 ID > Num > 1 Num > rs_rate > (240,240) rs_rate > Mode > AA Mode > Rate > the Rate > modulation > BPSK modulation > T