DC offset compensation
View Patent ↗A method for estimating an unwanted component that a receiver introduces into a signal at a known frequency, the method comprising applying a frequency offset to a signal, which comprises a wanted component at the known frequency, to form an offset signal having a frequency spectrum in which the wanted component is not positioned at the known frequency, processing the offset signal in the receiver and estimating a component positioned at the known frequency in the frequency spectrum of the processed signal.
1. A method for estimating an unwanted component that a receiver introduces into a signal, at a known frequency, in a single carrier communication system, the method comprising:
applying a frequency offset to a signal comprising a synchronization portion, the synchronization portion having a frequency spectrum comprising a plurality of substantially equally-spaced peaks, to form an offset signal having a frequency spectrum in which none of the substantially equally-spaced peaks is positioned at the known frequency;
processing the offset signal in the receiver;
estimating a component positioned at the known frequency in the frequency spectrum of the processed signal;
removing the estimated component from the processed signal; and
reversing the frequency offset in the signal from which the estimated component has been removed.
2. A method as claimed in claim 1 , comprising forming the synchronization portion to include a plurality of repeated blocks.
3. A method as claimed in claim 1 , comprising forming the synchronization portion such that each block comprises the same number of bits.
4. A method as claimed in claim 1 , comprising forming the synchronization portion such that each block consists of an identical bit pattern.
5. A method as claimed in claim 1 , comprising forming the synchronization portion to comprise at least two repeated blocks.
6. A method as claimed in claim 1 , comprising applying the frequency offset to be an odd-multiple of half of the spacing between two of the substantially equally-spaced peaks.
7. A method as claimed in claim 1 , comprising including a data portion in the signal and applying the frequency offset to the data portion.
8. A transceiver configured to apply a frequency offset to a signal in a single carrier communication system that comprises a synchronization portion, the synchronization portion having a frequency spectrum comprising a plurality of substantially equally-spaced peaks, to form an offset signal having a frequency spectrum in which none of the substantially equally-spaced peaks is positioned at the known frequency, whereby an unwanted component introduced at the known frequency into the offset signal by a receiver can be estimated;
wherein the transceiver further configured to remove the estimated unwanted component from the offset signal after it has been processed by the receiver; and
reverse the frequency offset in the signal from which the estimated component has been removed.
9. A transceiver as claimed in claim 8 , configured to apply the frequency offset to a data portion of the signal.
10. A transceiver as claimed in claim 8 , configured to form the synchronization portion of the signal to include a plurality of repeated blocks.
11. A transceiver as claimed in claim 10 , configured to form the synchronization portion such that each block comprises the same number of bits.
12. A transceiver as claimed in claim 10 , configured to form the synchronization portion such that each block consists of an identical bit pattern.
13. A transceiver as claimed in claim 10 , configured to form the synchronization portion to comprise at least two repeated blocks.
14. A transceiver as claimed in claim 8 , configured to apply the frequency offset to be an odd-multiple of half of the spacing between two of the substantially equally-spaced peaks.
15. A transceiver as claimed in claim 8 , configured to apply the frequency offset to the signal so as to generate an offset signal having substantially no signal energy at the known frequency.
16. A transceiver as claimed in claim 8 , wherein the signal comprises a synchronization portion and a data portion, the transceiver being configured to: apply the frequency offset to the synchronization portion and not the data portion so as to form a combined signal in which the offset synchronization portion has substantially no signal energy at the known frequency and the data portion comprises a wanted component at the known frequency; after processing the offset synchronization portion, estimate the component positioned at the known frequency in the processed synchronization portion; and after processing the data portion, subtract the estimated component from the processed data portion.
17. A method for estimating an unwanted component that a receiver introduces into a signal, at a known frequency, in a single carrier communication system, the method comprising:
applying a frequency offset to a signal comprising a synchronization portion, the synchronization portion having a frequency spectrum comprising a plurality of substantially equally-spaced peaks, to form an offset signal having a frequency spectrum in which none of the substantially equally-spaced peaks is positioned at the known frequency, wherein the frequency offset is applied to be an odd-multiple of half of the spacing between two of the substantially equally-spaced peaks;
processing the offset signal in the receiver; and
estimating a component positioned at the known frequency in the frequency spectrum of the processed signal.