Patent ID: 11909127
Assignee: NEC CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A calibration method comprising:
generating a reference signal having high auto-correlation;
delaying the reference signal to generate delayed reference signals having delay amounts different from each other;
outputting the reference signal and the delayed reference signals to transmission units, respectively, the transmission units respectively modulating input signals and output the modulated signals as output signals to the antenna elements;
combining the output signals of the transmission units to generate a combined signal; and
analyzing a correlation between a signal obtained by demodulating the combined signal and the reference signal to determine variations of timing, amplitude and a phase of the output signal of each transmission unit;
notifying the transmission units of determination results, wherein
each transmission unit calibrates the timing, amplitude and phase of the output signal based on a corresponding determination result.