Uniband Electronic Corp.

Li-Feng Chen

Yiping Fan

Chun-Chin Chen

Sheng-Wei Chiang

A radio frequency (RF) receiver has an antenna, a low-noise amplifier, a sigma-delta frequency synthesizer/voltage-controlled oscillator (VCO), an in-phase and quadrature (I/Q) mixer, a channel filter, and a digital baseband circuit. The digital baseband circuit has a demodulator, a preamble detection and carrier frequency offset (CFO) estimation circuit, and a CFO to sigma-delta modulation (SDM) input mapper. A preamble field of a digital demodulated signal generated by the demodulator is detected by the preamble detection and CFO estimation circuit. The RF receiver simultaneously compensates its CFO and optimizes a bandwidth of the channel filter based on the detection of the preamble field of the digital demodulated signal by the preamble detection and CFO estimation circuit.

RF receiver and method for simultaneously compensating carrier frequency offset and optimizing bandwidth by using preamble of a received RF signal

A signal receiver includes a multiplexer, a sub-sample analog-to-digital converter (ADC) and a received signal strength indicator (RSSI) estimator for a signal receiver with multiple stage cascade amplifiers architecture. The multiplexer may select one of the input signal of each stage of cascade amplifiers or the last stage output signal of cascade amplifiers as a selected signal according to a selection signal. The sub-sample ADC may perform a sub-sampling operation using the selected signal to generate sampled data. The RSSI estimator may calculate a RSSI value corresponding to the selected signal according to the sampled data.

Signal receiver for radio signal strength indication estimation with sub-sampling analog-to-digital converter for radio frequency signal with constant envelope modulation

An IEEE 802.15.4 DSSS Offset-QPSK device is proposed that allows an existing system to transfer Offset-QPSK modulation signal into MSK modulation signal, then deliver the MSK modulation signal without DSSS to increase payload data transmission rate. On-the-fly detection of whether a low data rate or a high data rate encoding mode is used for a received frame is attained by the transmitter setting a predetermined bit in the frame length byte of a transmitting frame. Thus an extra high data rate transmission for IEEE 802.15.4 DSSS Offset-QPSK systems can be provided.

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Taipei, Taiwan

Li-Feng Chen