Data independent error computation and usage with decision directed error computation
A signal error is determined by obtaining a known property of an expected signal. A signal is received and a signal error is determined based at least in part on the received signal and the known property of the expected signal.
1. A system for determining a signal error, comprising:
an interface configured to:
obtain a known property of an expected signal, wherein the known property of the expected signal includes an expected value of an absolute value of the expected signal; and
receive a signal; and
a processor configured to determine a signal error based at least in part on the received signal and the known property of the expected signal, including by:
taking an absolute value of the received signal; and
subtracting the expected value of the absolute value of the expected signal from the absolute value of the received signal to obtain a signal error associated with gain.
2. The system of claim 1 , wherein the system includes an application-specific integrated circuit (ASIC).
3. The system of claim 1 , wherein the system includes a field-programmable gate array (FPGA).
4. The system of claim 1 , wherein the system includes a storage system.
5. The system of claim 1 , wherein the system includes a communications transceiver.
6. A system for determining a signal error, comprising:
an interface configured to:
obtain a known property of an expected signal, wherein the known property of the expected signal includes an expected value of a square of the expected signal; and
a processor configured to determine a signal error based at least in part on the received signal and the known property of the expected signal, including by:
squaring the received signal; and
subtracting the expected value of the square of the expected signal from the square of the received signal to obtain a signal error associated with gain.
7. The system of claim 6 , wherein the system includes an application-specific integrated circuit (ASIC).
8. The system of claim 6 , wherein the system includes a storage system.
9. A method for determining a signal error, comprising:
obtaining a known property of an expected signal, wherein the known property of the expected signal includes an expected value of an absolute value of the expected signal;
receiving a signal; and
using a processor to determine a signal error based at least in part on the received signal and the known property of the expected signal, including by:
taking an absolute value of the received signal; and
subtracting the expected value of the absolute value of the expected signal from the absolute value of the received signal to obtain a signal error associated with gain.
10. The method of claim 9 , wherein the signal is received from a storage system.
11. The method of claim 9 , wherein the signal is received from a communications transceiver.
12. A system for selecting error computation, comprising:
a signal quality estimator configured to:
determine a signal quality based at least in part on a received signal; and
select between a decision directed error corrector and a data independent error corrector based at least in part on the signal quality;
the decision directed error corrector configured to determine an error signal based at least in part on a decision associated with the received signal; and
the data independent error corrector configured to determine an error signal based at least in part on a known property of an expected signal.
13. The system of claim 12 , wherein the signal quality estimator is configured to determine the signal quality based at least in part on one or more of the following: gain, offset or signal to noise ratio (SNR).
14. The system of claim 12 , wherein the signal quality estimator is configured to determine the signal quality by calculating an amplitude related value based at least in part on one or more of the following: a preamble portion of a received signal or a synchronization mark portion of a received signal.
15. The system of claim 12 , wherein the signal quality estimator is configured to determine the signal quality by calculating an offset related value based at least in part on one or more of the following: a preamble portion of a received signal or a synchronization mark portion of a received signal.
16. The system of claim 12 , wherein the signal quality estimator is configured to determine the signal quality by calculating a distance using a synchronization mark portion of a received signal.
17. A method for selecting error computation, comprising:
determining a signal quality based at least in part on a received signal; and
selecting between a decision directed error corrector and a data independent error corrector based at least in part on the signal quality;
in the event the decision directed error corrector is selected, using the decision directed error corrector to determine an error signal based at least in part on a decision associated with the received signal; and
in the event the data independent error corrector is selected, using the data independent error corrector to determine an error signal based at least in part on a known property of an expected signal.
18. The method of claim 17 , wherein the received signal is from a storage system.
19. The method of claim 17 , wherein the received signal is from a communications transceiver.
20. A method for determining a signal error, comprising:
obtaining a known property of an expected signal, wherein the known property of the expected signal includes an expected value of a square of the expected signal;
using a processor to determine a signal error based at least in part on the received signal and the known property of the expected signal, including by:
squaring the received signal; and
subtracting the expected value of the square of the expected signal from the square of the received signal to obtain a signal error associated with gain.