摘要:
A radio transmitter and a pilot signal inserting method are provided for improving throughput. In the radio transmitter, an MCS deciding part (106) selects one of a plurality of modulating systems. An information generating part (108) decides an inserting position of a pilot signal corresponding to the selected modulating system. A modulating part (116) modulates a data signal by the selected modulating system. A signal arranging part (118) inserts the pilot signal into the modulated data signal and changes the inserting position of the pilot signal corresponding to the selected modulating system. A transmission RF part (124) transmits the data signal wherein the pilot signal is inserted.
摘要:
In order to perform appropriate reception quality control on each mobile station in a multimedia broadcast/multicast service, a layered coding section 101 encodes input data by dividing the input data into two layers and obtains a first layer code string and a second layer code string. The first layer code string is input to a CRC code addition section 102 and a CRC code for an error inspection is added thereto at every predetermined block. On the other hand, the second layer code string is input to a CRC code addition section 103 and a CRC code for an error inspection is added thereto at every predetermined block. The first layer code string and the second layer code string with the CRC codes added are input to a layered modulation section 104 and the layered modulation section 104 modulates a plurality of code strings coded by being divided into a plurality of layers in such away that error rates differ hierarchically among the plurality of code strings and a radio section 105 sends the modulated symbol.
摘要:
A retransmission request signal creation section (119) outputs an ACK signal or NACK signal to a NACK signal counting section (120) based on the result of error detection by an error detection section (118), the NACK signal counting section (120) counts, for each communication mode, the number of NACK signals output (that is, the number of data retransmissions) before an ACK signal is output from the retransmission request signal creation section (119), and a table rewriting section (121) compares the number of retransmissions counted by the NACK signal counting section (120) with a predetermined threshold value for the number of retransmissions, and rewrites the contents of a communication mode table (102) based on the result of this comparison.
摘要:
Multicarrier transmission apparatus 100 receives channel quality information of subcarriers from multicarrier reception apparatus 200 and interleave pattern setting section 108 sets an interleave pattern according to channel quality of subcarriers. Interleaver 106 interleaves I components and/or Q components of symbols using the set interleave pattern. As a result, it is possible to optimize diversity gains in modulation diversity modulation/demodulation according to channel quality.
摘要:
An interference power calculation section 208 calculates an interference power value of each symbol according to a calculation expression (interference power=average power of parts unaffected by interference+average power of parts affected by interference) and notifies a turbo decoding section 209 of the calculated interference power value. The turbo decoding section 209 calculates σ2 used to calculate an LLR of turbo decoding according to a calculation expression (σ2=thermal noise+interference power) based on the interference power value notified from the interference power calculation section 208 and thereby changes σ2 based on the interference power value for each symbol notified from the interference power calculation section 208.
摘要:
A retransmission request signal creation section (119) outputs an ACK signal or NACK signal to a NACK signal counting section(120) based on the result of error detection by an error detection section(118), the NACK signal counting section(120) counts, for each communication mode, the number of NACK signals output (that is, the number of data retransmissions) before an ACK signal is output from the retransmission request signal creation section(119), and a table rewriting section(121) compares the number of retransmissions counted by the NACK signal counting section(120) with a predetermined threshold value for the number of retransmissions, and rewrites the contents of a communication mode table(102) based on the result of this comparison.
摘要:
In a multimedia broadcast/multicast service, in order to control the ratio of mobile stations capable of receiving information with high quality among mobile stations existing in a cell, a modulation section modulates a first layer code string and second layer code string heaving hierarchically different error rates into a symbol including both layer code strings, a target value storage section stores a target value corresponding to the ratio of high quality mobile stations which receive both the first layer code string and second layer code string without errors, a transmit power determining section determines to increase transmit power when the ratio of high quality mobile stations calculated by a ratio calculation section is less than a target value stored in the target value storage section and a transmit power control section increases transmit power of the modulated symbol according to the determination.
摘要:
In order to reduce interference between cells through hopping and use frequencies in a good propagation situation, a scheduler section 102 carries out scheduling for determining to which user data should be sent using CQI from each communication terminal apparatus, selects a user signal to be sent in the next frame and determines in which subcarrier block the data should be sent. An MCS decision section 103 selects a modulation scheme and coding method from the CQI of the selected user signal. A subcarrier block selection section 110 selects a subcarrier block instructed by the scheduler section 102 for each user signal. For the respective subcarrier blocks, FH sequence selection sections 111-1 to 111-n select hopping patterns. A subcarrier mapping section 112 maps the user signal and control data to subcarriers according to the selected hopping pattern.
摘要:
A base station effectively transmits BCH data and includes an encoding unit for encoding the BCH data; a modulation unit for modulating the BCH data after being encoded; a transmission band setting unit for setting a BCH data transmission band in one of sub carriers constituting an OFDM symbol; encoding units for encoding user data, modulation units for modulating user data after being encoded; and an IFFT unit for mapping the BCH data and the user data to each of the sub carriers and performing IFFT to generate an OFDM symbol. Here, the IFFT unit maps the BCH data to the sub carrier existing in the transmission band set by the transmission band setting unit among the plurality of sub carriers.
摘要:
The invention relates to methods for transmitting and receiving a data bit stream in a communication system using 16-QAM constellations. Further, an apparatus for performing the methods is provided. To improve the bit-error rate performance of the communication using the 16-QAM constellations the invention suggests the use 16-QAM constellations with specially selected mapping rules together with a special constellation rearrangement for creating different versions of the 16-QAM constellations. Further, the data stream is transmitted according to a diversity scheme employing different versions of the 16-QAM constellations obtained adhering the mapping rules and rearrangement rules defined by the invention.