摘要:
A method and system for assigning uplink (UL) slots to optimize time division duplex (TDD) UL power. In order to assure proper power control gain, UL slots are judiciously allocated close to the beacon slot. The UL slots may be allocated based on channel sensing. All users are sorted in the order of reducing fading losses. Sorting information is also used to allocate the UL slots. The UL slots may also be allocated based on signal interference information, code usage availability estimates and spread signal interference values. Alternatively, block error rate (BLER) and signal to interference ratio (SIR) measurements may be used to allocate the UL slots.
摘要:
The present invention is a method and apparatus for improving the performance of spatial temporal turbo channel coding (STTCC) used in multiple-input multiple-output (MIMO) wireless communication systems called eigen-STTCC (E-STTCC) that employs eigen-beamforming to make use of orthogonal eigen streams in the MIMO channel. Singular value decomposition (SVD) is applied to the channel matrix producing a linear precoding matrix containing the orthonormal basis for the eigen streams. In a first embodiment, the turbo encoded codeword containing concatenated systematic and parity bits is precoded with the linear precoding matrix such that the systematic bits are transmitted over the eigen streams with highest power. In a second embodiment, the codeword is made up of interleaved systematic bits and parity bits prior to eigen beamform preceding, effectively interleaving the systematic and data bits spatially over the eigen streams. In an alternate embodiment, the data stream is interleaved at the input to the encoder.
摘要:
A method and apparatus for implementing hybrid automatic repeat request (H-ARQ) in a multiple-input multiple-output (MIMO) wireless communication system are disclosed. A transmitter transmits at least two data packets via two or more antennas. If at least one of the data packets is not successfully transmitted, the transmitter retransmits the data packets while rearranging the data packets in an orthogonal spreading manner. Alternatively, the transmitter may retransmit only the unsuccessfully transmitted data packet along with a new data packet which replaces a successfully transmitted data packet. The unsuccessfully transmitted data packet may simply be repeated without changing its format. When only the unsuccessfully transmitted data packet is retransmitted along with the new data packet, the transmissions may be combined to recover the retransmitted data packet and the new data packet simultaneously.
摘要:
A stopping rule for Turbo decoding that is applied for both good and bad code blocks is disclosed. If the iteration either converges or diverges, decoding is terminated. In an alternative embodiment, the result of the stopping rule testing may be used for H-ARQ acknowledgement generation: if the iteration converges, an ACK is generated and if the iteration diverges, a NACK is generated. Optionally, the maximum number of decoding iterations may be dynamically selected based on MCS levels.
摘要:
A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.
摘要:
A user equipment (UE) for controlling transmission power levels in a system employing a spread spectrum time division duplex (TDD) technique having frames with timeslots for communication comprises a measuring device configured to receive, during a first time slot, a communication including a power level and measure the power level of the received communication and an interference power level. A pathloss estimation device determines a pathloss estimate and a long term pathloss estimate, based in part on the measured power level and the received power level. A quality measurement device determines a first quality factor, α, and a second quality factor, 1−α, of the pathloss estimate based in part on a number of timeslots, D, between the first and a second timeslot. A transmit power calculation device sets a transmission power level for transmission during the second timeslot.
摘要:
A weighted open loop power control system for controlling transmission power levels using a spread spectrum time division duplex (TDD) technique having frames with timeslots for communication comprises a receiver and a transmitter. The receiver includes a reference channel data generator, a spreading and training sequence insertion device, an amplifier, a summer, a modulator, and an antenna. The transmitter includes a demodulator configured to receive a transmitted signal from the receiver, a channel estimation device, a data estimation device, and a weighted open loop power controller. The weighted open loop power controller includes a power measurement device, a pathloss estimation device configured to receive an interpreted power level from the data estimation device and estimate the pathloss and update a long term average of the pathloss, a quality measurement device, and a transmit power calculation device for determining the transmitter's power level and to control the receiver's amplifier.
摘要:
An ACK/NACK method and system for use in time division duplex (TDD) and frequency division duplex (FDD) systems. In high speed downlink packet access (HSDPA), based on the assignment of timeslots for the high speed shared information channel (HS-SICH), each user equipment (UE) can be assigned two (2) different channelization codes. It is then possible to adopt the signaling convention that one code represents acknowledge error-free (Ack) and the other code shall represent acknowledge error condition (Nack). The Node B is able to distinguish the presence of the transmitted channelization code as opposed to the channelization code which is not transmitted. The probability of error, using this invention is an order of a magnitude smaller than if the Ack/Nack were signaled using typical modulation techniques.
摘要:
The present invention provides embodiments for producing a user equipment identification scrambling sequence (UEIDSS). The produced sequences for different user identification codes have a high separation. A base station uses the UEIDSS to scramble a high speed shared control channel (HS-SSCH) and a user equipment (UE) uses the UEIDSS to descramble the HS-SSCH. The embodiments utilize various blocks for producing the codes. These blocks include Reed-Muller encoding, concatenation, rate matching, segmentation, convolutional encoding, tail bit discarding, zero padding, repeating, CRC calculation, quadratic residue coding, parity-check bit, shortening, puncturing and BCH encoding blocks.
摘要:
A preamble for a random access channel (RACH) transmission is provided by selecting one out of sixteen preamble signatures. Each of the sixteen preamble signatures having sixteen symbols. A code is produced based on the preamble sequence. The produced code is phase rotated to produce a preamble code.