How do you measure ACPR?

In order to measure ACPR, one must provide the device under test (DUT) with a modulated stimulus – or in the case of a DAC – internally generate a modulated signal on the DUT itself. Intermodulation distortion describes the linearity of a device when presented with a multi-tone stimulus.

What is adjacent channel rejection?

Definition. Receiver adjacent channel rejection is the measure of how well a receiver can receive the transmitted signal in the presence of a high-level interfering signal in the adjacent channel. It is measured as a frame error ratio (FER) or packet error rate (PER) at specified interferer power levels.

How do you find the adjacent channel power ratio?

There are two ways of measuring ACPR. The first way is by finding 10*log of the ratio of the total output power to the power in adjacent channel. The second (and much more popular method) is to find the ratio of the output power in a smaller bandwidth around the center of carrier to the power in the adjacent channel.

How do you increase your Aclr?

One way is to use band pass filter at the input of final stage amplifier which will reduces the harmonics and improve the ACLR at the input of final stage power amplifier, so the overall ACLR of TX chain will improve.

What is adjacent channel interface?

The adjacent-channel interference which receiver A experiences from a transmitter B is the sum of the power that B emits into A’s channel—known as the “unwanted emission”, and represented by the ACLR (Adjacent Channel Leakage Ratio)—and the power that A picks up from B’s channel, which is represented by the ACS ( …

What is adjacent channel interference in GSM?

Interference resulting from signals which are adjacent in frequency to the desired signal is called adjacent channel interference. Adjacent channel interference results from imperfect receiver filters which allow nearby frequencies to leak into the passband.

How do you prevent adjacent channel interference?

The ACI can be reduced by: (1) using modulation schemes which have low out-of-band radiation; (2) carefully designing the bandpass filter at the receiver front end; and (c) assigning adjacent channels to different cells in order to keep the frequency separation between each channel in a given cell as large as possible.