Receiver device, communication system, and reception method
According to one embodiment, a receiver device includes: a plurality of converters each configured to sample a digital value from an analog signal, each digital value being sampled at different timing; and a digital signal processor configured to calibrate offsets of the digital values. The plurality of converters include a first converter and a second converter. The digital signal processor is configured to: calibrate a first offset caused in the first converter and a second offset caused in the second converter, in a first operation using a first analog signal; and calibrate a third offset that is caused commonly in the first converter for which the first offset is calibrated and the second converter for which the second offset is calibrated, in a second operation using a second analog signal.
1 . A receiver device comprising:
a plurality of converters each configured to sample a digital value from an analog signal, each digital value being sampled at different timing; and
a digital signal processor configured to calibrate offsets of the digital values,
wherein
the plurality of converters include a first converter and a second converter, and
the digital signal processor is configured to:
perform to calibrate a first offset caused in the first converter and a second offset caused in the second converter, in a first operation using a first analog signal that is input to the first converter and the second converter; and
perform to calibrate a third offset that is caused commonly in the first converter for which the first offset is calibrated and the second converter for which the second offset is calibrated, in a second operation using a second analog signal that is different from the first analog signal, the second analog signal being input to the first converter and the second converter after the first operation, and wherein
the first analog signal includes a random signal,
the second analog signal includes a data signal different from the random signal, and
a pattern length of the random signal and a number of the plurality of converters are coprime.
2 . The receiver device according to claim 1 , wherein
the digital signal processor is further configured to:
perform no calibration of the third offset in the first operation; and
perform no calibration of the first offset and no-calibration of the second offset in the second operation.
3 . The receiver device according to claim 1 , wherein
in the first operation,
the first converter is configured to sample a first digital value from the first analog signal;
the second converter is configured to sample a second digital value from the first analog signal; and
the digital signal processor is further configured to calibrate the first offset based on the first digital value, and calibrate the second offset based on a difference between the first digital value and the second digital value, and
in the second operation,
the first converter is configured to sample a third digital value from the second analog signal;
the second converter is configured to sample a fourth digital value from the second analog signal; and
the digital signal processor is further configured to calibrate the third offset based on a sum of the third digital value and the fourth digital value.
4 . The receiver device according to claim 1 , wherein
the first operation is performed prior to the second operation.
5 . A communication system comprising:
the receiver device as recited in claim 1 ; and
a transmitter device configured to transmit the analog signal to the receiver device.
6 . The communication system according to claim 5 , wherein
in the first operation, the transmitter device is configured to select a random signal having a pattern length coprime to a number of the plurality of converters as the first analog signal.
7 . The communication system according to claim 6 , wherein
the transmitter device is configured to receive the number of the plurality of converters or a prime number regarding the number of the plurality of converters from the receiver device.
8 . The communication system according to claim 5 , wherein
the digital signal processor is further configured to:
perform no calibration of the third offset in the first operation; and
perform no calibration of the first offset and no-calibration of the second offset in the second operation.
9 . The communication system according to claim 5 , wherein
in the first operation,
the first converter is configured to sample a first digital value from the first analog signal,
the second converter is configured to sample a second digital value from the first analog signal, and
the digital signal processor is further configured to calibrate the first offset based on the first digital value, and calibrate the second offset based on a difference between the first digital value and the second digital value, and
in the second operation,
the first converter is configured to sample a third digital value from the second analog signal,
the second converter is configured to sample a fourth digital value from the second analog signal, and
the digital signal processor is further configured to calibrate the third offset based on a sum of the third digital value and the fourth digital value.
10 . The communication system according to claim 5 , wherein
the first operation is performed prior to the second operation.
11 . A reception method for use in a receiver device comprising a plurality of converters including a first converter and a second converter, each of the plurality of converters being configured to sample a digital value from an analog signal, each digital value being sampled at different timing, the reception method comprising:
performing to calibrate a first offset caused in the first converter and a second offset caused in the second converter, in a first operation using a first analog signal that is input to the first converter and the second converter; and
performing to calibrate a third offset that is caused commonly in the first converter for which the first offset is calibrated and the second converter for which the second offset is calibrated, in a second operation using a second analog signal that is different from the first analog signal, the second analog signal being input to the first converter and the second converter after the first operation, wherein
the first analog signal includes a random signal,
the second analog signal includes a data signal different from the random signal, and
a pattern length of the random signal and a number of the plurality of converters are coprime.
12 . The reception method according to claim 11 , further comprising:
performing no calibration of the third offset in the first operation; and
performing no calibration of the first offset and no calibration of the second offset in the second operation.
13 . The reception method according to claim 11 , further comprising:
in the first operation, calibrating the first offset based on a first digital value sampled from the first analog signal by the first converter, and calibrating the second offset based on a difference between the first digital value and a second digital value sampled from the first analog signal by the second converter; and
in the second operation, calibrating the third offset based on a sum of a third digital value sampled from the second analog signal by the first converter and a fourth digital value sampled from the second analog signal by the second converter.
14 . The reception method according to claim 11 , wherein
the first operation is performed prior to the second operation.