Codex Corporation

Ping Dong

Vedat M Eyuboglu

Optimal baud rate and carrier frequency for data transmission using a modem on a communication channel (100) are determined by utilizing an on-line line probing technique. The technique utilizing the information from a decoder noise power spectrum estimated from the equalized received modulated signals and decoder output symbols to determine the decoder signal-to-noise ratios (SNRs) and supported bit rates for the available baud rates and carrier frequencies. These SNRs and bit rates together with a band edge SNR difference at each frequency band are utilized to select (110) the optimal baud rate and carrier frequency.

Device and method for on-line adaptive selection of baud rate and

A self-adjusting phase-locked loop (PLL) parameter adjusting device (APAD) (100) and method that automatically adjusts a phase-locked loop to provide tracking ability when and where needed, as opposed to utilizing a PLL adjusting device with preset parameters, thus maintaining minimal possible noise bandwidth. The method utilizes (1) successively integrating the PLL error output signal over a number of samples to provide a plurality of sums, (2) checking a predetermined number of sums and recording and counting the sign of each sum, (3) comparing the counted record to a predetermined threshold value, and (4) automatically adjusting PLL parameter(s) and the sample number in accordance with a predetermined strategy, such that adjusted PLL parameters are provided to the PLL.

Device and method for automatically adjusting a phase-locked loop

A device and method for asynchronous cyclic redundancy checking (CRC) for digital receivers includes utilizing a finite impulse response (FIR) filter, and comparing and gating circuits. The FIR filter may contain a first multiple delay system unit (102) and a first logic gating system (104). The comparing and gating circuit may contain a second multiple delay system unit (106), and a second logic gating system (110). The device and method is implementable, where desired, utilizing a computer program. The invention provides a faster determination of a CRC frame synchronization on a received digital signal.

Device and method for asynchronous cyclic redundancy checking for

A modem for receiving data sent from a remote device over a communication channel by using a single carrier modulated signal, the modem including a receiver for receiving the modulated signal and for receiving a line probing signal sent by the remote device over the channel, the receiver being capable of receiving the modulated signal over any one of a plurality of frequency bands; a line probing processor for measuring characteristics of the channel based upon the received line probing signal; and a selector for selecting one of the plurality of frequency bands, said selection being based upon the measured characteristics of the channel, said selected frequency band to be used for receiving the modulated signal from the remote device.

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