Frequency-hopped IFDMA communication system

• US 8,000,268 B2
• Filed: 06/30/2004
• Issued: 08/16/2011
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Fukuta, Masaya, Baum, Kevin L., Nangia, Vijay, Hayashi, Hiroshi
• Primary Examiner(s): JAIN, RAJ K
• Application Number:
  US10/881,252
• Publication Number:
  US 20060002451A1
• Time in Patent Office: 2,603 Days
• Field of Search: None
• US Class Current: 370/260
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 2201/70706 with means for reducing the peak-to-average power ratio
• CPC Class Codes: H04L 27/2602 Signal structure

Abstract

Frequency hopping in an IFDMA system takes place by utilizing a time-varying IFDMA modulation code. In particular, a modulator receives a symbol stream and a user specific IFDMA modulation code (bⁱ(t)). The output of the modulator comprises a signal (xⁱ(t)) existing at certain frequencies, or subcarriers. The actual subcarriers that signal xⁱ(t) utilizes is dependent upon the repetition of the symbol blocks and the particular IFDMA modulation code utilized.

Claims

1. A method performed by a wireless transmitter for frequency hopping within an interleaved frequency division multiple access (IFDMA) communication system, the method comprising steps of:

receiving, by the wireless transmitter, a symbol stream;

receiving, by the wireless transmitter, a first IFDMA modulation code;

at a first time period, modulating, by the wireless transmitter, the symbol stream with the first IFDMA modulation code to produce a symbol stream that occurs at a first set of frequencies;

receiving, by the wireless transmitter, a second IFDMA modulation code, wherein the second IFDMA modulation code is different from the first IFDMA modulation code; and

at a second time period, frequency hopping the symbol stream by modulating, by the wireless transmitter, the symbol stream with the second IFDMA modulation code to produce a symbol stream that occurs at a second set of frequencies;

wherein the set of frequencies at which the symbol stream occurs is dependent upon the IFDMA modulation code utilized to modulate the symbol stream and wherein the first and the second time periods comprise a first and a second symbol period.

2. The method of claim 1 wherein the step of receiving the first and the second IFDMA modulation code comprises the step of receiving a first and a second IFDMA block modulation code.

3. The method of claim 1 wherein the step of receiving the first and the second IFDMA modulation code comprises the step of receiving a first and a second IFDMA phase ramp modulation code.

4. A method performed by a wireless transmitter for frequency hopping within an interleaved frequency division multiple access (IFDMA) communication system, the method comprising steps of:

receiving, by the wireless transmitter, a symbol stream; and

frequency hopping, by the wireless transmitter, the symbol stream by modulating the symbol stream using different IFDMA modulation codes during each of a first and second IFDMA symbol period to produce symbol streams that occurs at different sets of frequencies,

wherein the different set of frequencies at which the symbol stream occurs is dependent upon the different IFDMA modulation codes utilized to modulate the symbol stream.

5. The method of claim 4 wherein the step of changing the IFDMA modulation code comprises the step of changing an IFDMA phase ramp modulation code.

6. The method of claim 4 wherein the step of changing the IFDMA modulation code comprises the step of changing an IFDMA block modulation code.

7. A method performed by a wireless receiver for receiving a frequency-hopped signal in an interleaved frequency division multiple access (IFDMA) communication system, the method comprising steps of:

receiving, by the wireless receiver, a symbol stream over a plurality of channels at a plurality of frequencies, wherein the plurality of channels includes a first plurality of channels and a second plurality of channels;

using a first IFDMA modulation code, by the wireless receiver, to demodulate the symbol stream received over the first plurality of channels and a first set of frequencies of the plurality of frequencies; and

frequency hopping the symbol stream by using a second IFDMA modulation code, by the wireless receiver, to demodulate the symbol stream received over the second plurality of channels and a second set of frequencies of the plurality of frequencies, wherein the first IFDMA modulation code is applied to the symbol stream during a first symbol period and the second IFDMA modulation code is applied to the symbol stream during a second symbol period.

8. The method of claim 7 wherein the first and the second symbols streams are received over a first and a second frame.

9. The method of claim 8 wherein the step of using the first and the second IFDMA modulation code comprises the step of using a first and a second IFDMA block modulation code.

10. The method of claim 8 wherein the step of using the first and the second IFDMA modulation code comprises the step of using a first and a second IFDMA phase ramp modulation code.

11. An apparatus comprising:

a symbol block repeater to output a block-repeated symbol stream;

a modulation code vector generator to output a time-varying interleaved frequency division multiple access (IFDMA) modulation code, wherein the time-varying interleaved frequency division multiple access (IFDMA) modulation code includes a first IFDMA modulation code and a second, different IFDMA modulation code; and

an IFDMA modulator to receive the block-repeated symbol stream and the time-varying modulation code, to modulate the symbol stream with the first IFDMA modulation code at a first time period to create a first modulated signal existing at a first set of frequencies that are dependent upon the first IFDMA modulation code, and to frequency hop the symbol stream by modulating the symbol stream with the second IFDMA modulation code at a second time period to create a second modulated signal existing at a second set of frequencies that are dependent upon the second IFDMA modulation code, wherein the first and the second time periods comprise a first and a second symbol period.

12. The apparatus of claim 11 wherein the IFDMA modulation code comprises a block modulation code or a phase ramp modulation code.

13. The apparatus of claim 11 wherein the time-varying IFDMA modulation code comprises a frame-by-frame varying IFDMA modulation code.

14. An apparatus comprising:

a baseband converter to receive a frequency-hopped interleaved frequency division multiple access (IFDMA)-modulated signal, which IFDMA-modulated signal is received over a plurality of channels at a plurality of frequencies, and outputting a baseband filtered signal existing at a plurality of frequencies; and

a demodulator to receive a IFDMA modulation code and the plurality of frequencies and outputting a demodulated signal based on the IFDMA modulation code, wherein the demodulator is configured to use a first IFDMA modulation code during a first symbol period to demodulate the IFDMA-modulated signal as received over a first plurality of channels of the plurality of channels and a first set of frequencies of the plurality of frequencies, and to frequency hop the symbol stream by using a second IFDMA modulation code during a second symbol period to demodulate the IFDMA-modulated signal received over a second plurality of channels of the plurality of channels and a second set of frequencies of the plurality of frequencies.

15. The apparatus of claim 14 wherein the IFDMA modulation code comprises a time-varying block modulation code.

16. The apparatus of claim 14 wherein the IFDMA modulation code comprises a time-varying ramp modulation code.

17. The apparatus of claim 14 wherein the frequency-hopped IFDMA-modulated signal is frequency hopped on a frame-by-frame basis.