Method and system for multirate multiuser modulation
First Claim
1. A method of modulating a signal, comprising:
- providing an interleaved frequency division multiple access (IFDMA) modulation scheme for transferring information using a communication system;
providing assignment rules for defining a plurality of data rates; and
modulating the signal using the IFDMA modulation scheme and at least one of the data rates.
4 Assignments
0 Petitions
Accused Products
Abstract
A multi-rate interleaved frequency division multiple access (IFDMA) modulation scheme permits users to transmit at different data rates or to vary their data rates while providing frequency diversity and preserving low peak-to-average power ratios and orthogonality between users at different data rates. The modulation scheme allows user-specific data block and repetition sizes, as well as user-specific modulation codes. Code assignment rules are provided for maintaining orthogonality between users having different data rates. Block and phase ramp modulation codes can be used. Asynchronous transmissions by users are supported by ensuring that the length of the cyclic extension is sufficiently long to tolerate worst case relative signal arrival delays between users and the channel pulse response duration over the communication medium. The modulation scheme can be employed in wireless communication systems, such as cellular or paging systems.
-
Citations
48 Claims
-
1. A method of modulating a signal, comprising:
-
providing an interleaved frequency division multiple access (IFDMA) modulation scheme for transferring information using a communication system;
providing assignment rules for defining a plurality of data rates; and
modulating the signal using the IFDMA modulation scheme and at least one of the data rates. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
- 8. An apparatus, comprising, a transmitter modulating a signal at a selected one of a plurality of data rates using an interleaved frequency division multiple access (IFDMA) modulation scheme.
-
16. A communication system, comprising:
-
a transmitter modulating a signal using a multi-rate interleaved frequency division multiple access (IFDMA) modulation scheme; and
a receiver, operatively coupled to the transmitter over a channel, for demodulating the signal using a multi-rate IFDMA demodulation scheme.
-
-
22. A method of demodulating a signal, comprising:
-
equalizing the signal;
correlating the equalized signal with a predetermined modulation code;
combining block repetitions of the correlated signal; and
detecting one or more symbols based on the combined block repetitions. - View Dependent Claims (23, 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41)
-
-
28. A method of demodulating a signal, comprising:
-
correlating the signal with a predetermined modulation code;
combining block repetitions of the correlated signal; and
detecting one or more symbols based on the combined block repetitions.
-
-
35. A receiver, comprising:
-
an equalizer for equalizing an input signal;
a correlator, operatively couple to the equalizer, for correlating the equalized signal using a predetermined modulation code; and
a block combiner, operatively coupled to the correlator, for combining block repetitions of the correlated signal.
-
-
42. A receiver, comprising:
-
a correlator for correlating a signal using a predetermined modulation code;
a block combiner, operatively coupled to the correlator, for combining block repetitions of the correlated signal; and
an equalizer, operatively coupled to the block combiner, for equalizing the output of the block combiner. - View Dependent Claims (43, 44, 45, 46, 47, 48)
-
Specification