Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information.

2023年3月16日 · Quadrature，正交的意思，QAM就是 正交幅度调制。 在通信这个学科里面，正交是指这两个信号有90°的相位差。 也就是在QAM里面，既有相位调制，又有幅度调制。 这一改还不得了，不仅有4QAM，8QAM，16QAM..... 甚至还有1024QAM。 一下子就把调制的信息翻了好多倍，牛x的不得了了。 QAM的原理是什么呢？ 我们从一个最简单的信号说起。 按照三角函数公式展开就是. 这样就把信号s (t)展开成了两个相位相差90°的正交信号的和，这个两个正交信号 …

2025年1月21日 · 对于QAM系统，其实整体流程都是一致的，无非就是 4QAM 是每 2 个bit映射到一个复数， 8QAM 是 3 个bit， 16QAM 是 4 个比特， 以此类推。 当然，随着阶数的不断升高，其抗干扰能力越弱，约容易出现误码，需要对系统进一步进行优化已保障调制解调的成果，本文仅为学习整体基本流程，不考虑系统优化等问题。 公式推导我们以 16QAM 为例，其他的大同小异。 16QAM 4个bit用一个复数进行表示，我们先看一下16QAM的 映射表 和 星座图。 QAM的调制. …

QAM is better than QPSK in terms of data carrying capacity. QAM takes benefit from the concept that two signal frequencies; one shifted by 90 degree with respect to the other can be transmitted on the same carrier. For QAM, each carrier is ASK/PSK modulated. Hence data symbols have different amplitudes and phases.

2020年8月23日 · QAM (Quadrature Amplitude Modulation) is defined as a modulation technique that combines phase and amplitude modulation in a single channel. It transmits information by changing both the amplitude and phase of a carrier wave, doubling the effective bandwidth. QAM is also known as quadrature carrier multiplexing.

2023年9月12日 · Quadrature amplitude modulation (QAM) has played a pivotal role in the industry's ability to scale data speed and capacity with user demand over the last 30 years. In this article we describe QAM using basic mathematics and illustrate how a QAM modulator operates.

Carrier Detect Determine a threshold value by inspecting your power estimate. The following figure shows the portion of received QAM signal and the power estimate average.

2025年2月28日 · Quadrature Amplitude Modulation (QAM) is a widely used digital modulation scheme in modern telecommunications. It efficiently transmits data by combining both amplitude and phase variations of a carrier signal. QAM plays a crucial role in various communication systems, including wireless networks, broadband internet, and digital television.

QAM is a generalization of PAM to bandpass channels. It uses bandwidth efficiently and linear channel distortions can be corrected by adaptive equalization at the receiver. QAM fits in nicely with a combined coding and modulation scheme called trellis coded modulation (TCM) and a method for selecting transmitted symbols known as shell mapping.

2011年3月8日 · 本文探讨了QAM调制中的缩放因子计算方法，并通过具体例子介绍了16-QAM和64-QAM的平均能量计算过程。 文中还提供了一种简单的方法来确定M-QAM调制中确保符号平均能量为一所需的缩放因子。