Abstract: One embodiment of the present invention provides an apparatus for allowing a Wi-Fi module to operate over TV white space (TVWS) bands. The apparatus includes a first receiver coupled to a Wi-Fi module and configured to receive a Wi-Fi signal from the Wi-Fi module, an analog-to-digital conversion (ADC) module coupled to the first receiver and configured to convert the received Wi-Fi signal to the digital domain, a spectral-shaping module configured to reshape a spectrum of the converted digital Wi-Fi signal, a digital-to-analog conversion (DAC) module coupled to the spectral-shaping module, and a first transmitter coupled to the DAC module and configured to transmit signals in TV white space (TVWS) bands.

Abstract: A hybrid fiber/coax digital data transmission system in which data from a plurality of subscribers are transmitted upstream to a headend demodulator in a series of data bursts. The headend demodulator acquires and synchronizes a data burst by detecting a BPSK preamble having a repetitive one and zero pattern (10101010101000). The pattern is detected by integrating clock energy in an envelope of a preamble length transmission and using the last three symbols (0,0,0) as a frame marker after differential decoding. Noise in the system is periodically measured by detecting an empty burst placed periodically in the data stream. A first-in, first-out (FIFO) memory allows closer spacing for the data bursts by permitting asynchronous received and output clocks.