DSP algorithms for carrier and timing recovery

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The general objective of the applicant's research is to increase the rate at which digital information can be communicated over analog media like twisted pair, coaxial cable, optical fiber and radio  channels. Examples of where  digital information is sent over an analog channel are cellular telephone, digital TV and the internet. Unfortunately, digital data can not be sent directly over an analog medium. It must be converted to an analog signal that is suitable for transmission. The device that converts the digital data to appropriate analog signal and visa versa is called a modem.   The operation of a receiving modem is quite complex, but it basically has three parts. The first part samples the incomming analog signal and changes the continuous analog signal into a sequence of numbers. The sampling rate is usually quite high, for example this part of the modem could convert the analog signal into stream of 20 million numbers per second. The second part of the modem is critical and requires sophistacted processing. It must synchronizes a clock in receiving modem to the clock that was used in the transmitting modem. It does this by analysing the stream of numbers.  The third part of the modem uses the synchonized clock to help decipher the stream of numbers and reconstruct the digital data that was sent by the transmitter. The applicant is interested in the second part of the modem. The intent is to find a faster and yet cheaper way to synchronize the clock in the receiver modem to the clock in the transmitter modem.  In doing so, modems could communicate over analog channels at higher information rates and at a lower cost.