AVIAT NETWORKS: Official Wireless Transmission Blog

1. What is QAM?

Modulation is a data transmission technique that transmits a message signal inside another higher frequency carrier by altering the carrier to look more like the message. Quadrature Amplitude Modulation (QAM) is a form of modulation that uses two carriers—offset in phase by 90 degrees—and varying symbol rates (i.e., transmitted bits per symbol) to increase throughput. The table in this blog post (Figure 1) describes the various common modulation levels, associated bits/symbol and incremental capacity improvement above the next lower modulation step.

2. Must all operators who use microwave backhaul use higher-order QAMs?

Higher-order QAMs are not necessarily a must-have for all network operators. However, higher-order modulations do provide one method of obtaining higher data throughput and are a useful tool for meeting LTE backhaul capacity requirements.

3. What is the main advantage of using higher-order QAMs with microwave radios?

The main advantage is increased capacity, or…

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6 thoughts on “

    • fasa 90 derajat lay *ya iya lah :p*
      kalo berubah fasa 90 derajat itu maksudnya, kan rumus sinyal misalnya sinus, berarti kl 90 derajat kan dia di titik paling tinggi gt.. tergantung modulasi apa dulu siih :3 pergeseran fasa apa perubahan fasa 90 derajat niih?

      Like

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