Apparatus and method for transmission of high speed data over communication channels

• US 6,047,022 A
• Filed: 02/28/1997
• Issued: 04/04/2000
• Est. Priority Date: 02/28/1997
• Status: Expired due to Term

• Current Assignee: STMicroelectronics NV
• Original Assignee: Orckit Communications Ltd. (Orckit-Corrigent )
• Inventors: Reuven, Ilan
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Tran, Khai
• Application Number:
  US08/807,336
• Time in Patent Office: 1,131 Days
• Field of Search: 375/222, 375/219, 375/261, 375/298, 375/316, 375/358, 375/340, 333/14, 379/416, 379/406, 379/410, 379/411, 370/286, 370/282, 370/289, 370/290
• US Class Current: 375/222
• CPC Class Codes: H04L 25/4921 using quadrature encoding, e.g. carrierless amplitude-phase coding
• CPC Class Codes: H04L 27/00 Modulated-carrier systems

Abstract

This invention discloses an apparatus for transmission of high speed data over communication channels, the apparatus including a modulator operative to modulate an outgoing stream of digital data, thereby to generate an outgoing signal, and a demodulator operative to demodulate an incoming signal, thereby to generate an incoming stream of digital data, wherein the modulator comprises a band suppressor for suppressing portions of the outgoing signal which have specified frequencies.

Claims

1. Apparatus for reception of high speed data from a noisy communication channel, the apparatus comprising:

a demodulator at one end of the noisy communication channel which receives and demodulates a primary input comprising signal and noise, the demodulator comprising;

a decision unit generating a decision output A_p from the primary input;

a noise canceller receiving a noise canceller input signal X_p and generating a noise canceller output signal Y_p, the noise canceller including;

a first adaptive digital filter receiving a first filter input signal U_p and generating a first filter output signal V_p, and a second adaptive digital filter receiving a second filter input signal W_p and generating a second filter output signal H_p ;

a first adder for combining first and second adder inputs X_p and A_p into a first adder output U_p, the first adder including a first delay unit delaying said first adder input, said first adder input comprising said noise canceller input signal X_p, said second adder input comprising decision output A_p, said first adder output comprising the first filter input signal U_p to the first adaptive digital filter;

a second adder for combining third and fourth adder inputs X_p and V_p into a second adder output Z_p, said third adder input comprising the noise canceller input signal X_p, said fourth adder input comprising the first filter output signal V_p ;

a third adder for combining fifth and sixth adder inputs Z_p and A_p into a third adder output W_p, the third adder including a second delay unit delaying said fifth adder input, said fifth adder input comprising the second adder output Z_p, said sixth adder input comprising the decision output A_p, and wherein the third adder output W_p comprises the second filter input signal;

a fourth adder for combining seventh and eighth adder inputs Z_p and H_p into a fourth adder output Y_p, said seventh adder input comprising the second adder output Z_p, said eighth adder input comprising the second filter output signal H_p, and

wherein the noise canceller output signal Y_p is a function of the sum of the first and second filter output signals V_p and H_p.

2. Apparatus according to claim 1 wherein said first adaptive digital filter comprises an adaptive infinite impulse response filter.

3. Apparatus according to claim 1 wherein said second digital filter comprises a FIR filter.

4. Apparatus according to claim 1 wherein said first digital filter comprises a FIR filter.

5. Apparatus according to claim 1 and also comprising a modulator operative to modulate an outgoing stream of digital data, thereby to generate an outgoing signal which is transmitted over the noisy communication channel to generate said incoming signal.

6. Apparatus according to claim 1 wherein the second filter input signal W_p is fed to the first filter as an error signal and wherein coefficients of the first filter are modified responsive to the value of the error signal.

7. Apparatus for reception of high speed data from a noisy communication channel, the apparatus comprising:

a demodulator at one end of the noisy communication channel which receives and demodulates a primary input comprising signal and noise, the demodulator comprising;

a decision unit generating a decision output A_p from the primary input;

a noise canceller receiving a noise canceller input signal X_p and generating a noise canceller output signal Z_p, the noise canceller including;

an adaptive IIR digital filter receiving a filter input signal U_p and generating a filter output signal V_p ;

a first adder for combining first and second adder inputs X_p and A_p into a first adder output U_p, the first adder including a first delay unit delaying said first adder input, said first adder input comprising said noise canceller input signal X_p, said second adder input comprising decision output A_p, said first adder output comprising the filter input signal U_p to the adaptive digital filter; and

a second adder for combining third and fourth adder inputs X_p and V_p into a second adder output Z_p, said third adder input comprising the noise canceller input signal X_p, said fourth adder input comprising the filter output signal V_p,

wherein the output of the noise canceller comprises a function of the filter output signal V_p.

8. Apparatus according to claim 7 and also comprising a modulator operative to modulate an outgoing stream of digital data, thereby to generate an outgoing signal which is transmitted over the noisy communication channel to generate said incoming signal.

9. A method for reception of high speed data from a noisy communication channel, the method comprising:

employing a demodulator at one end of the noisy communication channel to receive and demodulate a primary input comprising signal and noise, the employing step comprising;

generating a decision output A_p from the primary input;

receiving a noise canceller input signal X_p and generating a noise canceller output signal Y_p, including;

providing a first filter input signal U_p and generating a first filter output signal V_p, and providing a second filter input signal W_p and generating a second filter output signal H_p ;

combining first and second adder inputs X_p and A_p into a first adder output U_p, including delaying said first adder input, said first adder input comprising said noise canceller input signal X_p, said second adder input comprising decision output A_p, said first adder output comprising the first filter input signal U_p to a first adaptive digital filter;

combining third and fourth adder inputs X_p and V_p into a second adder output Z_p, said third adder input comprising the noise canceller input signal X_p, said fourth adder input comprising the first filter output signal V_p ;

combining fifth and sixth adder inputs Z_p and A_p into a third adder output W_p, including delaying said fifth adder input, said fifth adder input comprising the second adder output Z_p, said sixth adder input comprising the decision output A_p, and wherein the third adder output W_p comprises the second filter input signal;

combining seventh and eighth adder inputs Z_p and H_p into a fourth adder output Y_p, said seventh adder input comprising the second adder output Z_p, said eighth adder input comprising the second filter output signal H_p, and

wherein the noise canceller output signal Y_p is a function of the sum of the first and second filter output signals V_p and H_p.

10. A method for reception of high speed data from a noisy communication channel, the method comprising:

employing a demodulator at one end of the noisy communication channel to receive and demodulate a primary input comprising signal and noise, the employing step comprising;

generating a decision output A_p from the primary input;

receiving a noise canceller input signal X_p and generating a noise canceller output signal Z_p, including;

providing a filter input signal U_p and generating a filter output signal V_p ;

combining first and second adder inputs X_p and A_p into a first adder output U_p, including delaying said first adder input, said first adder input comprising said noise canceller input signal X_p, said second adder input comprising decision output A_p, said first adder output comprising the filter input signal U_p to an adaptive digital filter; and

combining third and fourth adder inputs x_p and V_p into a second adder output Z_p, said third adder input comprising the noise canceller input signal X_p, said fourth adder input comprising the filter output signal V_p,

wherein the output of the noise canceller comprises a function of the filter output signal V_p.