Communication systems based on high-gain signaling

Abstract

Systems, methods and apparatus for transferring data at a high rate. Examples may provide transmitters and receivers that transfer data at a high rate by encoding the data to be transmitted such that the circuits of the transmitter and receiver operate in their high-gain states. The encoded signal may have an average value that is independent of the data that is conveyed by the transmitted signal. In other examples, the encoding may shape the data signal into a data signal having a high-pass characteristic. When the high-pass encoded signal is transmitted through a channel having a low-pass transfer function, the resulting output signal may have much lower ISI compared to a un-encoded input signal. Transmit and receive circuits, such as amplifiers, laser, and photo-diodes, are biased to operate in their high-gain regions when receiving the encoded data in order to provide high-bandwidth and shorter transition times.

What is claimed is: 
     
         1 . A transmitter comprising:
 an encoder having at least one input adapted to receive a data signal, the encoder capable of encoding the data signal into an encoded multi-level data signal having substantially reduced DC and low-frequency components; and   an output stage coupled to receive the encoded multi-level data signal and to transmit the encoded multi-level data signal,   wherein the output stage is configured to have a transfer function that includes a high-gain linear region, and wherein the output stage is conditioned to operate at least substantially in the high-gain linear region when receiving and transmitting the encoded multi-level data signal.   
     
     
         2 . The transmitter of  claim 1  wherein the output stage is conditioned to operate near a center of the high-gain linear region and remains substantially in its high-gain linear region when transmitting the encoded multi-level data signal. 
     
     
         3 . The transmitter of  claim 1  wherein the encoding of the data signal substantially reduces DC and low-frequency components of the data signal whereby, in frequency domain, the encoded multi-level data signal has one of a substantially high-pass spectrum or a substantially band-pass spectrum. 
     
     
         4 . The transmitter of  claim 1  wherein the encoder is configured to encode a non-return to zero (NRZ) data signal to a dicode data signal. 
     
     
         5 . The transmitter of  claim 1  wherein the encoder is configured to encode a non-return to zero (NRZ) data signal to a modified dicode data signal. 
     
     
         6 . The transmitter of  claim 1  further comprising a serializing circuit having an output coupled to the at least one input of the encoder. 
     
     
         7 . The transmitter of  claim 1  wherein the output stage comprises a laser. 
     
     
         8 . The transmitter of  claim 1  wherein the output stage comprises a modulator. 
     
     
         9 . The transmitter of  claim 1  wherein the encoded multi-level data signal is a single-ended signal. 
     
     
         10 . The transmitter of  claim 1  wherein the encoded multi-level data signal is a differential signal.