5 results about "Peak detection" patented technology

An OFDM receiver includes an offset compensator (14) compensating for a frequency offset in a received OFDM signal. The offset compensator (14) includes a memory (51) storing two reference signals corresponding to arbitrary portions in the start symbol of the OFDM signal. A cross correlation value between the received OFDM signal and each of the two reference signals is calculated by a cross correlator (52, 53). Each peak position is detected by a peak detector (54). A frequency offset estimate value of the received OFDM signal is estimated by a frequency offset estimation circuit (55) based on the cross correlation value at each detected peak position. A phase rotation circuit (37) compensates for the frequency offset of the received OFDM signal based on the estimated frequency offset estimate value.

The invention particularly relates to a memristor-based automatic gain control circuit. The technical scheme is as follows: the circuit consists of a variable gain amplification module (1), a comparator (4) and a peak value detection module (5); the variable gain amplification module (1) consists of an operational amplifier circuit (2) and a memristor (3); a terminal M2 of the memristor (3) is connected with an input end Rc of the operational amplifier circuit (2); an input end Vi of the operational amplifier circuit (2) is externally connected with an input signal Vin; an output end VVGA of the operational amplifier circuit (2) is respectively connected with an input end VVGAP of the peak value detection module (5) and the input end Vw of a peripheral circuit; a terminal M1 of the memristor (3) is connected with an output end Vc of the comparator (4); an input end ViVGAP of the comparator (4) is connected with an output end ViVGA of the peak value detection module (5); and an input end VREF1 of the comparator (4) is externally connected with a reference electric level VREF. The memristor based automatic gain control circuit provided by the invention has the advantages of simple structure, low cost and high accuracy.

The invention relates to a nanosecond level pulse peak value detection method and belongs to the technical field of optical communication. According to the method, a nanosecond level pulse signal is broadened through a low-pass filter, then, a clock signal obtained after phase position adjustment is triggered, and therefore an analog-digital converter can sample data more accurately. Under the condition that a high-speed analog-digital converter is not needed, a nanosecond level pulse signal peak value can be detected. With the detection method, the requirement for the sampling rate of an analog-to-digital conversion unit can be lowered, the method is simple and easy to perform, and cost of the needed devices is low.