摘要:
A reference signal of a user equipment to which a resource (LB#1) is allocated for a L1/L2 control signal, is allocated a resource (SB#1) that is closer on the time axis to the resource (LB#1), which the L1/L2 control signal is allocated, within the same frequency band as the L1/L2 control signal. A reference signal for CQI estimation, independent of a data signal and a L1/L2 control signal, is allocated a resource with which at least one of a reference signal for demodulation of a data signal and a reference signal for demodulation of a L1/L2 control signal is not transmitted at the same timing within the transmission band. The types of bandwidths of the reference signals multiplexed in a same short block within a same band are reduced, whereby restrictions as to the number of reference signal sequences that can be secured are diminished.
摘要:
A memory 21 of a pilot processing circuit 2 holds in advance a pilot sequence converted into a frequency region signal obtained by subjecting a pilot signal symbol transmitted in one block to Ntx_p-point DFT. The pilot sequence held in the memory 21 is subjected to a series of processes including a roll-off filtering by a roll-off filter circuit 22, subcarrier mapping process by subcarrier mapping circuit 23, an Ndft_p-point IDFT operation by an IDFT circuit 24, and a cyclic prefix adding process by a cyclic prefix adding circuit 25.
摘要:
A radio communication system for quickly selecting an optimum transmission mode in accordance with the quality and situation of a propagation path is provided. The system comprises first and second radio communication apparatuses capable of radio-communicating with each other. The first radio communication apparatus comprises a propagation path environment estimator for outputting the estimation result as propagation path environment information, a propagation path quality estimator for outputting the estimation result as propagation path quality, and a transmitter for transmitting both the informations to the second radio communication apparatus. The second radio communication apparatus comprises a transmission mode selector for selecting one of the transmission modes used for communicating with the first radio communication.
摘要:
It is an object to provide a receiving apparatus which is capable of demodulating signals with a very simple arrangement. Receiving apparatus 1 has N reception antennas 11-1-11-N, and reception antennas 11-1-11-N receive signals. Channel coefficient estimator 12 estimates and outputs channel coefficients from the signals received by respective reception antennas 11-1-11-N. QR decomposer 13 is supplied with a channel matrix having the channel coefficients as its elements, performs QR decomposition on the channel matrix, and outputs a Q matrix and an R matrix. A QH processor 14 is supplied with the Q matrix and the received signals, multiplies the received signals by a complex conjugate transposed matrix of the Q matrix, and outputs converted signal z. A transmitted sequence estimator 15 is supplied with converted signal z and the R matrix and estimates transmitted sequences.
摘要:
N sub-carriers are grouped in units of predetermined quantities in order beginning with the one exhibiting the highest communication channel quality to generate an optimal group pattern on the reception side. Then, communication channel information is calculated for each of sub-carrier groups in the optimal group pattern or a quasi-optimal group pattern which is assumed to be closest to the optimal group pattern among a plurality of previously set group pattern candidates. Communication channel information is designated as modified communication channel information. Grouping information indicative of the optimal group pattern or quasi-optimal group pattern is combined with modified communication channel information to generate feedback information. On the transmission side, sub-carriers are grouped based on reproduced feedback information reproduced from the feedback information.
摘要:
A receiver estimates a channel quality. A transmitter amplifies a signal by a gain proportional to a difference between a required signal-to-noise power ratio and channel quality information, which is an estimation result of the channel quality, and transmits the signal so that the receiver can obtain the signal-to-noise power ratio. In this case, the receiver or the transmitter determines a roll-off rate of an adaptive filter based on the channel quality information. The transmitter uses the adaptive filter of the determined roll-off rate to filter and transmit the signal.
摘要:
A multi-user receiving apparatus is provided for achieving a reduction in the amount of processing for single-carrier FDMA signals and an improvement in reception characteristics. A DFT unit converts single-carrier FDMA received signals of all users to signals in a frequency domain commonly. A demapping unit selects part of sub-carriers for each user from sub-carriers supplied from the DFT unit. A reception filter separates a user signal and suppresses noise. A demodulator demodulates the user signal, and detects a timing thereof.
摘要:
A receiver estimates a channel quality. A transmitter amplifies a signal by a gain proportional to a difference between a required signal-to-noise power ratio and channel quality information, which is an estimation result of the channel quality, and transmits the signal so that the receiver can obtain the signal-to-noise power ratio. In this case, the receiver or the transmitter determines a roll-off rate of an adaptive filter based on the channel quality information. The transmitter uses the adaptive filter of the determined roll-off rate to filter and transmit the signal.
摘要:
An OFDM communication system which performs appropriate feedback flexibly adapted to channel states, while suppressing an amount of feedback information. The OFDM communication system has first and second communication apparatuses. In a second receiver of the second communication apparatus, a channel quality measurement part measures channel quality for each of sub-carriers. A time variation measurement part and a frequency measurement part respectively measure variation of channel quality in a time domain and a frequency domain, respectively, and output the variation of channel quality as time variation information and frequency variation information, also respectively. Based on the measured time variation information and frequency variation information, a two-dimensional control part performs two-dimensional blocking for forming two-dimensional blocks each from plural adjacent sub-carriers which are adjacent to each other in the time domain and the frequency domain. The two-dimensional control part measures and outputs channel quality of each two-dimensional block, as feedback information.
摘要:
A memory 21 of a pilot processing circuit 2 holds in advance a pilot sequence converted into a frequency region signal obtained by subjecting a pilot signal symbol transmitted in one block to Ntx_p-point DFT. The pilot sequence held in the memory 21 is subjected to a series of processes including a roll-off filtering by a roll-off filter circuit 22, subcarrier mapping process by subcarrier mapping circuit 23, an Ndft_p-point IDFT operation by an IDFT circuit 24, and a cyclic prefix adding process by a cyclic prefix adding circuit 25.