Method of multiple-carrier communication within a noncontiguous wideband spectrum and apparatus therefor
First Claim
1. A method of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels within a noncontiguous wideband channel, said method comprising:
- receiving a reference signal transmitted over each subchannel in said plurality of subchannels within said wideband channel;
producing a modulation profile of said wideband channel, wherein said modulation profile is responsive to a signal-to-noise ratio (SNR) for each subchannel in said plurality of subchannels within said wideband channel, wherein said producing activity comprisesestablishing a least-SNR requirement,determining said SNR for each of said subchannels in said plurality of subchannels within said wideband channel, anddesignating each of said subchannels having an SNR greater than said least-SNR requirement as a clear subchannel; and
transmitting OFDM data in response to said modulation profile.
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Accused Products
Abstract
A method (20) of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels (30) within a noncontiguous wideband channel (24) is provided. The method (20) determines an SNR for each of the subchannels (30). The method (20) then designates a subchannel (30) as clear (93) when its SNR is greater than a least-SNR threshold (70), as impeded (95) when its SNR is less than the least-SNR threshold and greater than an SNR-evaluation threshold, and as obstructed (111) when its SNR is less than both the least-SNR and the SNR-evaluation thresholds. The method (20) then transmits OFDM data (34) so that each of the clear subchannels receives the OFDM data (34) at a maximum subchannel signal level (40), each of the impeded subchannels receives the OFDM data (34) at an intermediate subchannel signal level (42), and each of the obstructed subchannels receives the OFDM data (34) at zero subchannel signal level (44).
50 Citations
28 Claims
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1. A method of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels within a noncontiguous wideband channel, said method comprising:
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receiving a reference signal transmitted over each subchannel in said plurality of subchannels within said wideband channel; producing a modulation profile of said wideband channel, wherein said modulation profile is responsive to a signal-to-noise ratio (SNR) for each subchannel in said plurality of subchannels within said wideband channel, wherein said producing activity comprises establishing a least-SNR requirement, determining said SNR for each of said subchannels in said plurality of subchannels within said wideband channel, and designating each of said subchannels having an SNR greater than said least-SNR requirement as a clear subchannel; and transmitting OFDM data in response to said modulation profile. - View Dependent Claims (2, 3, 4, 5)
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6. A method of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels within a noncontiguous wideband channel, said method comprising:
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producing a modulation profile of said wideband channel, wherein said modulation profile is responsive to a signal-to-noise ratio (SNR) for each subchannel in said plurality of subchannels within said wideband channel including establishing a least-SNR requirement, determining said SNR for each of said subchannels in said plurality of subchannels within said wideband channel, designating each of said subchannels having an SNR greater than said least-SNR requirement as a clear subchannel, sorting said subchannels by said SNRs therein, adjusting said least-SNR requirement, determining said SNR for each of said subchannels in said plurality of subchannels within said wideband channel, and designating each of said subchannels having an SNR greater than said adjusted least-SNR requirement as an impeded subchannel; and transmitting OFDM data in response to said modulation profile. - View Dependent Claims (7)
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8. A method of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels within a noncontiguous wideband channel, said method comprising:
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producing a modulation profile of said wideband channel, wherein said modulation profile is responsive to a signal-to-noise ratio (SNR) for each subchannel in said plurality of subchannels within said wideband channel including scanning said wideband channel, and determining said SNR for each of said subchannels in said plurality of subchannels within said wideband channel in response to said scanning activity, comprising ascertaining usable ones of said subchannels in response to said SNR of each of said subchannels, and estimating a bit error rate for each of said usable subchannels; and transmitting OFDM data in response to said modulation profile. - View Dependent Claims (9)
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10. A method of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels within a noncontiguous wideband channel, said method comprising:
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producing a modulation profile of said wideband channel, wherein said modulation profile is responsive to a signal-to-noise ratio (SNR) for each subchannel in said plurality of subchannels within said wideband channel including scanning said wideband channel, and determining said SNR for each of said subchannels in said plurality of subchannels within said wideband channel in response to said scanning activity, comprising ascertaining usable ones of said subchannels in response to said SNR of each of said subchannels, and estimating a throughput for each of said usable subchannels; and transmitting OFDM data in response to said modulation profile.
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11. A method of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels within a noncontiguous wideband channel, said method comprising:
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producing a modulation profile of said wideband channel, wherein said modulation profile is responsive to a signal-to-noise ratio (SNR) for each subchannel in said plurality of subchannels within said wideband channel; and transmitting OFDM data in response to said modulation profile; and wherein said transmitting activity transmits said OFDM data over the plurality of subchannels, from which more than one user channel is formed and concurrently supported. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An orthogonal frequency-division multiplex (OFDM) communication system utilizing a plurality of subchannels within a noncontiguous wideband channel, said system comprising:
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an OFDM receiver configured to obtain a signal-to-noise ratio (SNR) for each subchannel in said plurality of subchannels within said wideband channel, wherein said OFDM receiver comprises a scanning section configured to scan each of said subchannels in said plurality of subchannels within said wideband channel, a detection section coupled to said scanning section and configured to obtain said SNR for each of said subchannels, and an evaluation section coupled to said detection section and configured to designate as a clear subchannel each of said subchannels having a SNR greater than a least-SNR requirement; and an OFDM transmitter in communication with said OFDM receiver and configured to transmit OFDM data so that said OFDM receiver receives said OFDM data in each subchannel within said plurality of subchannels within said wideband channel at one of a zero subchannel signal level, a predefined maximum subchannel signal level which is greater than the zero subchannel signal level, and a predefined intermediate subchannel signal level which is greater than the zero subchannel signal level and less than the maximum subchannel signal level, in response to said SNR therein. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. A method of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels within a noncontiguous wideband channel, said method comprising:
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determining a signal-to-noise ratio (SNR) for each of said subchannels in said plurality of subchannels within said wideband channel; designating as a clear subchannel each of said subchannels in which said SNR is greater than or equal to a first least-SNR requirement; designating as an impeded subchannel each of said subchannels in which said SNR is less than said first least-SNR threshold and greater than or equal to a second least-SNR requirement; designating as an obstructed subchannel each of said subchannels not designated as one of said clear subchannels and said impeded subchannels; and transmitting OFDM data so that each of said clear subchannels receives said OFDM data at a maximum subchannel signal level, each of said impeded subchannels receives said OFDM data at an intermediate subchannel signal level, and each of said obstructed subchannels receives said OFDM data at zero subchannel signal level.
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Specification