Receiver having functions for cancelling DC offset and measuring carrier detection threshold value, and control method thereof
AssigneeNEC Corporation
InventorShigeru Sakuma
Life of this patent
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Abstract
An improved system and method for canceling a DC offset and measuring a carrier detection threshold value. A control circuit provides a signal based upon a frame synchronizing signal for shutting down the power to a mixer. Thereafter, at a predetermined time, the control circuit provides a signal to a DC offset cancel circuit to cancel the DC offset. Then, the control circuit provides a RSSI gate signal to a carrier detection circuit based upon the next frame synchronizing signal, for determining whether a carrier exists.
Claims11
A receiver for a time-division multiple access (TDMA) system, comprising:
- a controller, said controller generating a mixer power supply isolating signal, a DC offset gate signal and an RSSI gate signal based on a frame synchronizing signal;
- a switch, said switch switching a power supply of a mixer on and off based on said mixer power supply isolating signal;
- a DC offset cancel circuit, said DC offset cancel circuit canceling a DC offset generated at an A/D converter as a function of said DC offset gate signal;
- and
- a carrier detection circuit, said carrier detection circuit determining whether a carrier exists as a function of both an RSSI signal and said RSSI gate signal.
A receiver for a time-division multiple access (TDMA) system, comprising:
- control means for generating a mixer power supply isolating signal, a DC offset gate signal and an RSSI gate signal based on a frame synchronizing signal;
- switch means for turning a power supply of a mixer on and off based on said mixer power supply isolating signal;
- DC offset cancel means for canceling a DC offset generated at an A/D converter as a function of said DC offset gate signal, and
- carrier detection for means determining whether a carrier exists as a function of both an RSSI signal and said RSSI gate signal.
A control method of a receiver for a time-division multiple access (TDMA) system, comprising the steps of:
- generating a mixer power supply isolating signal, a DC offset gate signal and an RSSI gate signal based on a frame synchronizing signal;
- turning a power supply of a mixer on and off based on said mixer power supply isolating signal;
- canceling a DC offset generated at an A/D converter based on said DC offset gate signal;
- and
- determining whether a carrier exists as a function of both an RSSI signal and said RSSI gate signal.
Dependencies are inferred from the claim text.