Has been described the MIMO signal by frequency
Has been described the MIMO signal by frequency, amplitude, and the corresponding phase component definitions, measurement of MIMO signal must conduct accurate and true measurement of the above three signals characteristic components. Further MIMO system is usually based on the received signal is a Dell Inspiron 6000 battery zero intermediate frequency (zero-IF) downconverted to baseband I and Q signal components of the system. To obtain a high modulation accuracy, laptop batteries must be maintained to I, the fidelity of the Q signal component, which requires all of the components having a high performance and low distortion of signal path, including amplifier, filter, mixer, I / Q modulation and demodulator and other components.
In many wireless systems, error vector magnitude (EVM) is to evaluate the performance of the standard parameters, EVM measurement capture many parameters that define the transmission of the RF signal in the signal amplitude and phase errors and distortion is reduced to a parameter, to allow a comparison between Dell Inspiron 6400 battery the respective transmitter. Laptop battery the MIMO transmitter testing including the change in the assessment of the group delay and group delay, phase noise, enlarge compression and signal processing component I / Q mismatch. A signal distortion caused by the above factors can generally be seen by the EVM constellation.
In the constellation diagram of the EVM for a desired signal, all constellation points should be the ideal location to coincide exactly. Signal and the component is not perfect, such as constellation points in the phase noise and carrier leakage and other factors make on constellation is offset from the ideal position. EVM is a measurement of this offset, Dell Inspiron 640m battery the addition to the overall EVM as MIMO system testing parameters, EVM as frequency and EVM as time function can also provide analysis of the performance of the MIMO transmitter. In addition, the carrier and symbol EVMs display contrast can provide the further details of the performance of a MIMO transmitter.