| 摘要 |
PURPOSE:To automatically eliminate and correct an IQ amplitude imbalance and a DC offset by eliminating the need for manual adjustment so as to make the size small and the weight light. CONSTITUTION:The terminal equipment is provided with an orthogonal phase demodulator 8a comprising a DSP having an algorithm that divides sampling data into a group for each IQ4 coordinate when IQ phases are made orthogonal to each other and a DC offset and IQ amplitude imbalance are produced, estimates each parameter relating to an amplitude and a center coordinate of an ellipse equation passing through the IQ4 coordinate for each group, selects the group having a proper parameter by verifying the physical property of each parameter, averages the parameters of the group, uses the mean value for the IQ amplitude ratio and DC offset, subtracts the DC offset from the sampled data and multiplies the IQ amplitude ratio with the difference. |
