QAM

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QAM

QAM

In Q, or basic telecommunication code, it means, “What is the latest met (weather)?”

QAM

(1)

QAM

(2)
Quality Assurance Management.

QAM

(1) (Quality Assessment Measurement) A system used to measure and analyze voice transmission.

(2) (Quadrature Amplitude Modulation) A modulation technique that employs both phase modulation (PM) and amplitude modulation (AM). Widely used to transmit digital signals such as digital cable TV and cable Internet service, QAM is also used as the modulation technique in orthogonal frequency division multiplexing (see OFDM). The "quadrature" comes from the fact that the phase modulation states are 90 degrees apart from each other.

Analog QAM
Analog QAM uses two carriers 90 degrees out of phase with each other. Each carrier is modulated by an analog signal, and the resulting modulated waves are combined (see example below).

Digital QAM
In digital QAM, the number of modulation states determines how the digital signal is split up. For example, in 8QAM, each three bits of input alters the phase and amplitude of the carrier to derive eight unique modulation states (see example below).

In 16QAM, 32QAM, 64QAM, 128QAM, 256QAM, 512QAM and 1024QAM, from four to 10 bits generate from 16 to 1,024 modulation states respectively. See modulation and binary values.


Analog QAM
Analog QAM modulates two carriers 90 degrees out of phase with each from two analog input streams. The modulated carriers are combined and transmitted.







Digital QAM (8QAM)
In 8QAM, three input bits generate eight modulation states using four phase angles on 90 degree boundaries and two amplitudes (4 phases X 2 amplitudes = 8 states). Digital modulation greater than 8QAM is difficult to visualize.







Quadrature PSK (QPSK)
QPSK is like 4QAM without amplitude modulation. QPSK uses four phase angles to represent each two bits of input; however, the amplitude remains constant.
References in classic literature ?
If you will interpret the word INTOLERANCE as FIRMNESS OF PRINCIPLE, if you do not wish to condemn in the catholic soul of the Abbe de Sponde the stoicism which Walter Scott has made you admire in the puritan soul of Jeanie Deans' father; if you are willing to recognize in the Roman Church the Potius mori quam foedari that you admire in republican tenets,--you will understand the sorrow of the Abbe de Sponde when he saw in his niece's salon the apostate priest, the renegade, the pervert, the heretic, that enemy of the Church, the guilty taker of the Constitutional oath.
Social dissipation, fiant pilulae quam plurimae: to be taken, feasting, three times a day
And by him that spake only as a philosopher, and natural man, it was well said, Pompa mortis magis terret, quam mors ipsa.
Abbas beati Martini, SCILICET REX FRANCIAE, est canonicus de consuetudine et habet parvam proebendam quam habet sanctus Venantius, et debet sedere in sede thesaurarii
per Jehovam, Gehennam, et consecratam aquam quam nunc spargo,
Circa quam ergo hostiles inter se acies cum ingenti clamore hostiliter conveniunt.
The Board, accordingly, has appointed Quam Capital Limited ("Quam Capital ") as the independent financial adviser to provide advice in relation to the franchise period of the Desulfurisation Assets or Denitrification Assets under the Franchising Contracts.
HONG KONG, Nov 3, 2015 - (ACN Newswire) - Quam Limited ("Quam" or the "Group", Stock Code: 00952.
The bank said that it was in talks to purchase a controlling stake in Hong Kong-based securities firm, Quam Ltd, for USD970m.
Members were first briefed on the history of the show by Susan Quam, VP of the Wisconsin Restaurant Association, before exploring the show floor.
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