Wireless communication systems may use one or more channels to transfer data packet between a transmitter and a receiver. During transmission operations by the transmitter in a device, obtaining an accurate transmit power measurements is an important feature allowing for a regulatory conformance as well as predictable performance. For example, the transmit power measurements is utilized for power control flow such as a dynamic adjustment of a power level during transmission.
A typical approach when analyzing the transmission power of a Wi-Fi orthogonal frequency division multiplexing (OFDM) data packet, a radio frequency (RF) signal (at a power amplifier (PA) output) passes through an envelope detector (or a self-mixer) and subsequently is averaged to obtain the transmit power. With this approach, a signal from the envelope detector is typically digitalized and averaged. However, for signals with high peak-to-average power ratio (PAPR) like OFDM signals, the sampling rate of the digitizer needs to be substantially high in order to get low-variance statistics. Furthermore, data packet length needs to be long enough for low-variance statistics, which may sometimes render a change or impact to media access control (MAC) flows for adaptation of the packet length. The MAC flow impact is highly inconvenient and as such, measurements without changes to the MAC flows may provide efficient transmit power measurements.
USPTO Backgrounds
USPTO Backgrounds