Method to reduce peak to average power ratio in multi-carrier modulation receivers
Provided is a method for performing channel estimation in an Orthogonal Frequency Division Multiplexed (OFDM) signal. The method includes performing the channel estimation based upon use of reserved tone channel carriers.
1. A method for decreasing peak to average power ratio (PAPR) for a multicarrier modulation signal including two or more groups of carriers, the method comprising:
(a) during a first timeframe (i) assigning non-zero values for carrier types within a first of the two or more groups and (ii) assigning zero values for carrier types within a second of the two or more groups after assigning the non-zero values;
(b) during a second timeframe (i) choosing arbitrary non-zero values for the carrier types within the second group; and
(c) during a third timeframe optimally determining non-zero values for the carrier types within the second group based upon a predetermined PAPR threshold.
2. The method of claim 1 ; wherein step (a) includes selecting a target PAPR, choosing a set of reserved tones, and
wherein step (a) further comprises (iii) computing a first PAPR and determining whether the first PAPR meets predetermined constraints.
3. The method of claim 2 , wherein the step (a)(iii) includes computing a fast Fourier transform.
4. The method of claim 3 , wherein step (b) further comprises (ii) computing a second PAPR based upon the arbitrary non-zero value carrier types within the second group if the first PAPR does not meet the predetermined constraints and (iii) determining whether the computed PAPR meets predetermined constraints.
5. The method of claim 1 , wherein carrier types within the first group include at least one of data carriers, continuous pilots, and scattered pilots; and
wherein carrier types within the second group includes reserved tones.
6. The method of claim 1 , wherein steps (a)-(c) are performed during an initialization sequence.
7. The method of claim 6 , wherein the multi-carrier modulation signal is at least one of an orthogonal frequency division multiplexing (OFDM) signal and a discrete multi-tone modulation (DMT) signal.
8. The method of claim 7 , wherein steps (a)-(c) are performed within an OFDM transmitter.
9. A computer readable medium carrying one or more sequences of one or more instructions for execution by one or more processors to perform a method of decreasing peak to average power ratio (PAPR) for a multi-carrier modulation signal including two or more groups of carriers, the instructions when executed by the one or more processors, cause the one or more processors to:
(a) during a first timeframe (i) assign non-zero values for carrier types within a first of the two or more groups and (ii) assign zero values for carrier types within a second of the two or more groups after assigning the non-zero values;
(b) during a second timeframe (i) choose arbitrary non-zero values for the carrier types within the second group; and
(c) during a third timeframe optimally determine non-zero values for the carrier types within the second group based upon a predetermined PAPR threshold.
10. The computer readable medium of claim 9 , wherein step (a) includes selecting a target PAPR, choosing a set of reserved tones, and
wherein step (a) further comprises (iii) computing a first PAPR and determining whether the first PAPR meets predetermined constraints.
11. The computer readable medium of claim 10 , wherein the step (a)(iii) includes computing a fast Fourier transform.
12. The computer readable medium of claim 11 , wherein step (b) further comprises (ii) computing a second PAPR based upon the arbitrary non-zero value carrier types within the second group if the first PAPR does not meet the predetermined constraints and (iii) determining whether the computed PAPR meets predetermined constraints.
13. The computer readable medium of claim 9 , wherein carrier types within the first group include at least one of data carriers, continuous pilots, and scattered pilots; and
wherein carrier types within the second group includes reserved tones.
14. The computer readable medium of claim 9 , wherein steps (a)-(c) are performed during an initialization sequence.
15. The computer readable medium of claim 14 , wherein the multi-carrier modulation signal is at least one of an orthogonal frequency division multiplexing (OFDM) signal and a discrete multi-tone modulation (DMT) signal.
16. The computer readable medium of claim 15 , wherein steps (a)-(c) are performed within an OFDM transmitter.