摘要:
An apparatus, system, and method are described for multi-carrier communication using adaptive tone-pruning. The method may include transmitting a data-bearing signal over a plurality of tones on a communication loop within a plurality of communication loops and calculating a minimum tone cost according to a tone cost algorithm. The tone cost algorithm defines a tone cost associated with a selected tone within the plurality of tones. The tone cost of the selected tone is based on a predefined loading frequency and a signal-to-noise ratio (SNR) of the selected tone. The method also may include determining a bit loading pattern for the data-bearing signal according to the minimum tone cost. This determination may occur in response to a determination that a minimum allowable transmission power is greater than a minimum required transmission power for the data-bearing signal.
摘要:
Adaptive channelization is achieved in a high throughput multicarrier system by first subdividing a high throughput channel into a number of frequency sub-channels. A channelization decision may then be made within a device as to which of the sub-channels to use for a corresponding high throughput wireless link based on channel state information.
摘要:
Disclosed is an adaptive resource allocation processor in the multi-channel communication system. A channel gain for the subchannel is determined and a modulation method for each subchannel is the present invention. A number of bits to be transmitted is determine according to a subchannel quality, and a minimum power for a total required transmission rate is determined. A channel gain for the subchannel is determined according to the number of allocated bits and power, an, a modulation method for each subchannel is determined with reference o the channel gain. When the modulation method for each subchannel is determined, an adaptive convex search is repeatedly performed according to the average power and transmission rate, and a final modulation method is determined as one subchannel unit with reference the convex search result.
摘要:
A "power adaptive circular" (PAC) transmission scheme that can support both spatial multiplexing and transmit diversity for multi-carrier MIMO systems and has a number of desirable characteristics, including the ability to: transmit a variable number of symbol streams, provide transmit diversity for each transmitted symbol stream, support coded interference estimation technique at a receiver, and use power efficiently. In one method, at least one stream of symbols is received for transmission on a plurality of subbands and from a plurality of antennas. The at least one stream of symbols is multiplexed such that (1) the symbols in each stream are transmitted from the plurality of antennas (e.g., diagonally across the subbands and antennas) and (2) the at least one stream starts in the same subband. A stream of multiplexed symbols is formed for each antenna and further processed, and may be transmitted at full power available for the antenna.
摘要:
Disclosed are an adaptive pilot symbol assignment method that flexibly controls the number of transmit antennas according to each user's moving speed, channel status, or user request, and assigns proper pilot symbols in the downlink of an OFDMA (Orthogonal Frequency Division Multiplexing Access) based cellular system; and a sub-carrier allocation method for high-speed mobile that allocates some sub-carriers to assign proper pilot symbols for ultrahigh-speed mobile users, and the rest of the sub-carriers to the other users to assign proper pilot symbols to the users, on the assumption that the ultrahigh-speed mobile users have a traffic volume almost insignificant to the whole traffic volume.
摘要:
This disclosure relates to varying load and modulation applied to each of multiple frequency subchannels based on anticipated attenuation experienced by those subchannels. Communicating data includes identifying a static component of a transmission medium for wideband communications having at least two subchannels (110), determining a function of noise or attenuation versus frequency for the static component (120), selecting wideband modulation schemes for the subchannels based on the function determined (130, 140), and communicating a data signal over the subchannels (145). Independent demodulation functions may be applied to at least two of the subchannels.
摘要:
A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection compreses each of multiple subscribes measuring channel and interference information for subcarriers based on pilot symbols received from a base station, at least one of subscribers selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, andthe one subscriber receiving an indicaiton of subcarriers to the base station, and the one subscriber receiving an indication of subcarriers of the set of subcarriers selected bz the base station for use by the one subscriber.