Abstract:
PROBLEM TO BE SOLVED: To support mobile stations incapable of demodulating the entire bandwidth or capable of demodulating a less bandwidth than the entire bandwidth.SOLUTION: Users are scheduled on a less bandwidth than the entire bandwidth. Further, a certain user can be scheduled on a more bandwidth than other users.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques to more efficiently transmit pilots on demand on a reverse link.SOLUTION: Pilots are transmitted on demand on a reverse link and used for channel estimation and data transmission on a forward link. A base station selects at least one terminal for on-demand pilot transmission on the reverse link (210). Each of the at least one selected terminal is a candidate for receiving data transmission on the forward link. The base station assigns each of the at least one selected terminal with a time-frequency allocation (212), which may be for a wideband pilot, a narrowband pilot, or some other type of pilot. The base station receives and processes an on-demand pilot transmitted from each of the at least one selected terminal (216) and derives a channel estimate for the terminal based on the received pilot (218).
Abstract:
PROBLEM TO BE SOLVED: To provide a system and method for power control and scheduling of sub-carriers in an OFDM communication system.SOLUTION: A receiver dynamic range can be minimized by a power control loop that attempts to maintain received power over a noise floor in a predetermined range. If the received power relative to the noise floor in allocated sub-carriers exceeds the predetermined range and the total received power is at a minimum, a scheduling system allocates an additional sub-carrier to a communication link. Additionally, if the received power relative to the noise floor is less than the predetermined range minimum and the total received power is at a maximum, the scheduling system de-allocates the sub-carrier from the communication link. The scheduling system may also adjust an encoding rate to maintain a relatively constant symbol rate in each of the sub-carriers.
Abstract:
PROBLEM TO BE SOLVED: To provide a quick paging channel with reduced probability of missed page. SOLUTION: The quick paging channel in a random-connection radio communication system includes at least one bit in a quick paging frame, which can discriminate the existence of a paging message to an access terminal or an access terminal group. A quick paging bit to discriminate the existence of the paging message to the first access terminal is encoded together with one or more quick paging bits corresponding to one or more additional access terminals to constitute one or more forward error correction bit. The quick paging bit encoded at the same time is broadcast to a plurality of access terminals, by time-division multiplexing of the quick paging frame together with an additional information frame. Moreover, a paging block can be compressed. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide efficient pilot transmission system for multi-antenna communication systems. SOLUTION: In one pilot transmission system, a first set of T scaled pilot symbols is generated with a first training vector and transmitted (e.g., continuously) from T transmit antennas, where T>1. If MIMO receiver(s) are to be supported by the system, then at least T-1 additional sets of T scaled pilot symbols are generated with at least T-1 additional training vectors and transmitted from the T transmit antennas. The training vectors are for different (e.g., orthogonal) spatial directions. Each MISO receiver can estimate its MISO channel based on the first set of scaled pilot symbols. Each MIMO receiver can estimate its MIMO channel based on the first and additional sets of scaled pilot symbols. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method and apparatus for using different modulation schemes for retransmission of a packet. SOLUTION: A plurality of modulation schemes are used for a single packet, so that each data packet is processed and transmitted in up to T(T>1) blocks. The plurality of modulation schemes are used for the T blocks. A transmitter encodes a data packet to generate code bits. The transmitter then forms a block of code bits using the code bits generated for the packet, determines the modulation scheme to use for the block (e.g., based on a mode/rate), maps the code bits for the block based on the modulation scheme to obtain data symbols, and processes the block of data symbols and transmits the block to a receiver. The transmitter generates and transmits another block in similar manner until the data packet is decoded correctly or all T blocks have been transmitted. The receiver performs complementary processing to receive and decode the packet. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a communication system for efficiently transmitting a packet.SOLUTION: A packet may be partitioned into multiple subpackets, and each subpacket may be encoded separately. The subpackets are mapped to a subset of assigned resources. The resources include multiple tiles, each tile corresponding to a block of time frequency resources. The subpackets are mapped to an equal number of tiles to achieve similar decoding performance; each subpacket is mapped to at least Ntiles to achieve a certain minimum diversity order for the subpacket; and/or each subpacket is mapped to a subset of the multiple tiles so that the subpacket can be decoded without having to demodulate all of the tiles.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for encoding and decoding data.SOLUTION: Multiple code rates for a forward error correction (FEC) code may be supported, and a suitable code rate may be selected based on packet size. A transmitter may obtain at least one threshold to use for code rate selection, determine a packet size to use for data transmission, and select a code rate among the multiple FEC code rates based on the packet size and the at least one threshold. Multiple FEC codes of different types (e.g., Turbo, LDPC, and convolutional codes) may be supported, and a suitable FEC code may be selected based on packet size. The transmitter may obtain at least one threshold to use for FEC code selection and may select an FEC code among the multiple FEC codes based on the packet size and the at least one threshold.
Abstract:
PROBLEM TO BE SOLVED: To provide multi-carrier code division multiple access (MC-CDMA) being able to be used in an uplink of a wireless communication system.SOLUTION: Data symbols of each terminal from a modulator 214 are spread using a different set of orthogonal codes assigned to each terminal by an OFDM modulator 220, and each data symbol is mapped to a modulation symbol in a time-frequency block so that the data symbol is in a group not overlapping with a hopping duration based on FH sequence. An orthogonal waveform is generated and transmitted by an IFFT 224.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for using multiple modulation schemes for a single packet.SOLUTION: Each data packet is processed and transmitted in up to T blocks, where T>1. Multiple modulation schemes are used for the T blocks to achieve good performance. A transmitter encodes a data packet to generate code bits. The transmitter then forms a block of code bits with the code bits generated for the packet, determines the modulation scheme to be used for the block (e.g., based on a mode/rate selected for the packet), maps the code bits for the block based on the modulation scheme to obtain data symbols, and processes and transmits the block of data symbols to a receiver. The transmitter generates and transmits another block in similar manner until the data packet is decoded correctly or all T blocks have been transmitted. The receiver performs the complementary processing to receive and decode the packet.