Constrained hopping in wireless communication systems

• US 8,571,132 B2
• Filed: 12/21/2005
• Issued: 10/29/2013
• Est. Priority Date: 12/22/2004
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Khandekar, Aamod, Agrawal, Avneesh
• Primary Examiner(s): Ahn, Sam K
• Assistant Examiner(s): PANWALKAR, VINEETA S
• Application Number:
  US11/315,744
• Publication Number:
  US 20060146760A1
• Time in Patent Office: 2,869 Days
• Field of Search: 375/259, 375/260, 375/261, 375/316, 375/340, 375/346, 375/347, 375/349, 375/295, 375/219, 375/222, 375/285, 375/296, 370/203, 370/208, 370/464, 370/480.491, 370/498, 370/500, 455/39, 455/68, 455/69
• US Class Current: 375/295
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 1/0029 Reduction of the amount of signalling, e.g. retention of useful signalling or differential signalling power control H04W52/04
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0232 by interpolation between sounding signals
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

Embodiments described provide for channel estimation and resource allocation for a transmission to a wireless device. The frequency band is partitioned into at least two contiguous subbands. A determination is made whether it is desirable to transmit in a single subband or in more than one subband. The transmission is assigned to occur in either the single subband or to operate in more than one subband. If the transmission is restricted to one subband, the hop pattern is also restricted to subcarriers within the particular subband.

Claims

1. In a wireless OFDMA communication that estimates multiple channels in a MIMO system operating over a given frequency band, wherein channel estimation is more efficient for allocating resources when users'"'"' symbols are transmitted in a hopping pattern over the full band, a method comprising:

a) transmitting a user'"'"'s symbols in a hopping pattern over the full broadband;

b) receiving from a receiver a plurality of pilot signals in a more than one subband and a neighboring subband of a frequency band having an in range portion defined by a contiguous range of frequencies adjacent to the edge of the subband and an out of range portion defined by the remaining frequencies in the neighboring subband;

c) receiving a channel quality indicator (CQI) indicative of channel quality of each subband observed in a wireless device;

d) estimating a channel response-based on some of the plurality of pilot signals in more than one subband and the pilot signal in the range portion of the neighboring subband; and

e) assigning the transmission to occur in either the signal subband or to operate in more than one subband based on a determination of the channel quality indicator.

2. The method set forth in claim 1, further comprising estimating a channel response for a second subcarrier within the subband by utilizing pilot signals in a second subband and not those in the subband.

3. The method set forth in claim 1, wherein the subband includes only contiguous frequency subcarriers.

4. The method set forth in claim 1, wherein the subband includes non-contiguous frequency subcarriers.

5. A non-transitory machine readable medium having stored thereon instructions to:

a) transmit a user'"'"'s symbols in hopping pattern over the full broadband in a wireless OFDMA communication that estimates multiple channels in a MIMO system operating over a given frequency band;

determine that a pilot signal in a subband and a neighboring subband have been received at a receiver;

b) receive a plurality of pilot signals in more than a subband of a frequency band;

c) receive a channel quality indicator (CQI) indicative of channel quality of each subband observed in a wireless device;

d) estimate a channel response for a subcarrier within the subband based on some of the plurality of pilot signals received in one subband, for that one subband; and

e) assigning the transmission to occur in either the signal subband or to operate in more than one subband based on a determination of the channel quality indicator.

6. An apparatus for channel estimation that is more efficient for allocating resources when users'"'"' symbols are transmitted in a hopping pattern over the full band comprising:

a) means for transmitting a user'"'"'s symbols in a hopping pattern over the full broadband in a wireless OFDM communication that estimates multiple channels in a MIMO system operating over a given frequency band;

b) means for receiving a plurality of pilot signals in more than a subband of a frequency band;

c) means for receiving a channel quality indicator (CQI) indicative of channel quality of each subband observed in a wireless device;

d) means for estimating a channel response for a subcarrier within the subband based on some of the plurality of pilot signals in the subband and the pilot signal in the range of the neighboring subband received in one subband, for that one subband; and

e) means for assigning the transmission to occur in either the signal subband or to operate in more than one subband based on the determination.

7. The apparatus for channel estimation of claim 6 comprising:

a receiver front end for receiving a pilot signal in a subband and a neighboring subband of a frequency band, each subband comprises a plurality of subcarriers, and the neighboring subband having an in-range portion defined by a contiguous range of frequencies adjacent to the edge of the subband and an out-of-range portion defined by the remaining frequencies in the neighboring subband, wherein the neighboring subband is outside the subband; and

a channel estimating module connected with the receiver front end for estimating a channel response for a subcarrier within the subband by using the pilot signal in the in-range portion of the neighboring subband.

8. The apparatus of claim 7 wherein the plurality of subcarriers is a power of two.

9. The apparatus of claim 7 wherein the subband is a part of a partitioned frequency bandwidth.

10. The apparatus of claim 7 wherein the receiver front end is adapted to receive orthogonal frequency division multiplexed symbols.

11. The apparatus of claim 7 wherein the receiver front end is adapted to receive symbols over a MIMO channel.

12. The apparatus of claim 7 wherein the receiver front end is adapted to receive orthogonal frequency division multiple access symbols.

13. The apparatus of claim 7 wherein a hopping pattern is restricted to the subband.

14. The apparatus of claim 7 wherein subcarriers near the edge of the subband are not blanked out.