摘要:
International Mobile Telecommunications (IMT) Advanced technology, also known as 4th Generation (4G) targets to support up to 100 MHz BW. LTE currently supports single carrier bandwidths of up to 20 MHz. The present application describes a multi-carrier approach in which some embodiments of the invention provide a simple solution of aggregating multiple single carrier bandwidths to obtain a wider bandwidth (>20 MHz). Such an approach may extend Long Term Evolution (LTE) bandwidth to greater than that provided by a single carrier, yet maintain full backward compatibility with technologies that predate 4G technology and utilize smaller, single carrier bandwidths. More generally, embodiments of the invention can apply to other communication standards than only LTE.
摘要:
A method and system for wireless data communication using a first wireless communication technology and a second wireless communication technology. The second wireless communication technology being different from the first wireless communication technology. A transmitter is arranged to transmit data using frame structures based on the first wireless communication technology and the second wireless communication technology in which the frame structure based on the second wireless communication technology has a timing structure, MAC and pilot that are also used with the frame structure of the first wireless communication technology. The transmitter is arranged to selectively change transmission on a frame by frame basis between the first wireless communication technology and the second wireless communication technology.
摘要:
Soft handoff in an OFDMA system is disclosed. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone has subcarriers with a subchannel definition, for example, an identical permutation.
摘要:
A method and apparatus for transmitting and receiving a wireless transmission of a plurality of data streams in a wireless communication system having a plurality of nodes is disclosed. Each node has multiple antennas. The method involves receiving first and second data streams from respective first and second nodes at a receiver node, causing the receiver node to generate a receive filter for decoding each of the received data streams, and causing the receiver node to transmit receive filter information for each of the first and second data streams, the receive filter information facilitating precoding of the first and second data streams for simultaneous transmission within a common frequency band to the receiver node.
摘要:
Methods and apparatus are provided for inserting data symbols and pilot symbols in an OFDM (orthogonal frequency division multiplexing) transmission resource utilizing frequency hopping patterns for the data symbols and/or the pilot symbols. Data symbols and pilot symbols are allocated for down link (base station to mobile station) and up link (mobile station to bases station) transmission resources in a two-dimensional time-frequency pattern. For each antenna of a MIMO-OFDM (multiple input multiple output OFDM) communication system, pilot symbols are inserted in a scattered pattern in time-frequency and data symbols are inserted in an identical frequency-hopping pattern in time-frequency as that of other antennas.
摘要:
A wireless communication method and system using virtual MIMO (“V-MIMO”) are provided. Post processing signal to interference and noise ratios (“SINR”) for a plurality of signals corresponding to a plurality of mobile terminals arranged as a V-MIMO group are estimated. The one of the plurality of mobile terminals having the highest post processing SINR is selected. Wireless communication for the selected mobile terminal is scheduled. The signal corresponding to the selected mobile terminal is cancelled. Post processing signal to interference and noise ratios (“SINR”) for the signals corresponding to the remaining mobile terminals is re-estimated. The one of the remaining mobile terminals having the highest post processing SINR is selected. Wireless communication for the selected remaining mobile terminal is scheduled.
摘要:
The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-I and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.
摘要:
A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.
摘要:
In a wireless access network, a transmitter provides a pool of sequences having a reduced peak-to-average power ratio. Information to be transmitted is mapped to a selected at least one of the pool of sequences. The selected at least one sequence is transmitted over an orthogonal frequency division multiple access (OFDMA)-based wireless link of the wireless access network.
摘要:
A method and apparatus are provided for measuring channel quality over which has been transmitted a sequence of symbols produced by encoding and constellation mapping a source data element sequence. The method includes receiving a sequence of received symbols over the channel whose quality is to be measured. The sequence of received symbols is de-mapped based on a first channel quality indicator previously transmitted to a transmitter of the sequence of symbols. The method also includes decoding the de-mapped symbols to produce a decoded output sequence. In some embodiments, the decoding may be based on the first channel quality indicator. The method also includes re-encoding the decoded output sequence to produce a re-encoded output sequence. The method also includes correlating the de-mapped symbols with the re-encoded output sequence to produce a second channel quality indicator. The second channel quality indicator is transmitted to the transmitter to adaptively select a type of mapping based on the second channel quality indicator. In some embodiments, the transmitter may adaptively select a type of encoding based on the second channel quality indicator.