US 9,813,265 B2
Receiver DC offset calibration with antenna connected
Qiang Lin, San Jose, CA (US)
Assigned to GainSpan Corporation, San Jose, CA (US)
Filed by GainSpan Corporation, San Jose, CA (US)
Filed on Apr. 14, 2015, as Appl. No. 14/686,688.
Prior Publication US 2016/0308695 A1, Oct. 20, 2016
Int. Cl. H04L 25/06 (2006.01); H04B 17/21 (2015.01)
CPC H04L 25/061 (2013.01) [H04B 17/21 (2015.01)] 11 Claims
OG exemplary drawing
 
1. A wireless device comprising:
a receiver to receive a receive signal from one or more other wireless devices;
an antenna connected to the receiver;
a processor to determine a DC offset value of the wireless device with the antenna connected by performing energy detection and averaging, and calibrate the wireless device using the determined DC offset value,
wherein the energy detection and averaging comprise, each time when the receiver has filled a sample buffer of an analog to digital converter with a plurality of samples, determining an average of the plurality of the samples in the sample buffer to obtain a DC power of the system, computing a total power of the plurality of the samples, computing an AC power of the plurality of samples by subtracting the DC power from the total power, comparing the AC power to a predetermined threshold, wherein only if the AC power is higher than the predetermined threshold, the AC power and the DC power are rejected, and only if the AC power is below the predetermined threshold, moving average buffers are updated with the AC power and the DC power, and
wherein an averaged AC power and the DC offset value are determined by averaging the AC power with previous AC power values and averaging the DC power with previous DC power values in the moving average buffers, respectively; and
memory to store the DC offset value.