Abstract:
By estimating the movement direction of a communication partner, the radiation pattern is forcibly rotated to thereby form a correct radiation pattern. Specifically, an apparatus of the present invention includes reception radiation pattern control section for providing a reception signal from an antenna with a first reception radiation pattern by a first control signal, radiation pattern control section for providing the abovementioned reception signal with a second reception radiation pattern by a second control signal based on an output of movement direction estimating section for estimating a movement direction of a transmitting side, and a reception signal processing system having multiplication section for multiplying the abovementioned reception signal by the first control signal and the second control signal. Consequently, even when the movement speed of the transmitting side or the receiving side is high, by causing a reception radiation pattern controller or a transmission radiation pattern controller to respond to the movement to thereby form a correct radiation pattern, the transmission and reception performance can be improved.
Abstract:
By estimating the movement direction of a communication partner, the radiation pattern is forcibly rotated to thereby form a correct radiation pattern. Specifically, an apparatus of the present invention includes reception radiation pattern control section for providing a reception signal from an antenna with a first reception radiation pattern by a first control signal, radiation pattern control section for providing the abovementioned reception signal with a second reception radiation pattern by a second control signal based on an output of movement direction estimating section for estimating a movement direction of a transmitting side, and a reception signal processing system having multiplication section for multiplying the abovementioned reception signal by the first control signal and the second control signal. Consequently, even when the movement speed of the transmitting side or the receiving side is high, by causing a reception radiation pattern controller or a transmission radiation pattern controller to respond to the movement to thereby form a correct radiation pattern, the transmission and reception performance can be improved.
Abstract:
A diversity receiver estimates a reception weight sing signals received at a plurality of antennas, a target pattern former forms a target radiation pattern based on the estimated reception weight, a transmission pattern former forms a transmission radiation pattern with a transmission weight using an arbitrary transmission weight as an initial value, a controller limits an angle range in which formation of the target radiation pattern and formation of the transmission radiation pattern are executed, an error detector detects an error between the target radiation pattern and the transmission radiation pattern, and subjects the detected error to logarithmic transformation, an updator updates the transmission weight so as to reduce the error subjected to logarithmic transformation, and a directivity former provides a transmission signal with a directivity according to the transmission radiation pattern formed using an updated transmission weight.
Abstract:
When carrying out directive reception using an adaptive array antenna apparatus, a plurality of diversity reception circuits which differ in communication environment follow-up performance are used for reception and the reception output with the best reception quality is selected. The environment follow-up performance of the other non-selected diversity reception circuits is dynamically changed, preferably every time a selection is made by a selector based on the environment follow-up performance of a selected diversity reception circuit.
Abstract:
A CMA-based antenna system is disclosed which shows an improved receiving performance by reducing phase differences in the received signals which have been weighted. The CMA-based antenna system comprises a plurality of antenna, weight circuits, an adder, an error detector and a synthesis controller. The synthesis controller controls the weight circuits so as not only to make the adder output at a preset level but also to cause any differences among the weight circuit outputs not to increase. In order to cope with an error of symbol synchronization and a delayed wave, the CMA-based antenna system may further have a kind of equalizer inserted before the weight circuit in each antenna circuit.
Abstract:
An adaptive transmission diversity apparatus utilizes a spread spectrum system, detects radiation patterns of direct and indirect waves, which have arrived in a time-shifted manner, by reception radiation pattern controllers. A transmission radiation pattern controller is utilized in accordance with a transmission radiation pattern. The transmission radiation pattern is determined by selecting a pattern from reception radiation patterns obtained by the reception radiation pattern controllers. This can ensure a higher transmission performance.
Abstract:
Received signal provided via plural antennas 101 are memorized in memory 102. First weight controller 103 calculates the first weights by which the received signals are weighted, and second weight controller 104 calculates the second weights using the received signals. Multipliers 107 and 108 multiply the memorized received signals by the first weights, while multiply the memorized received signals by the second weights when a channel quality of radio signals deteriorates due to a change of the radio signal's direction of arrival Adder 109 synthesizes the multiplication results. Propagation path distortion compensator 110 estimates a deterioration of the channel quality using synthesis result to compensate. Detector 111 detects the compensation result that is used as a parameter to calculate the first and second weights, which allows the apparatus to receive radio signals without deteriorating reception qualities when the channel quality deteriorates rapidly due to the change of the radio signal's direction of arrival.
Abstract:
Provided are a base station, a terminal, a band allocation method, and a downlink data communication method in which a mapping method for synchronization signals and report signals is implemented with high resource usage efficiency when a first system in which an independent single communication is allocated to a unit band co-exists with a second system in which a plurality of unit bands can be allocated to a single communication. In a base station (200), an OFDM signal generation unit (225) maps primary synchronization channel (P-SCH), secondary synchronization channel (S-SCH), primary broadcast channel (P-BCH), and dynamic broadcast channel (D-BCH), which can be decoded by both an LTE terminal and an LTE+ terminal, to some of a plurality of unit bands available to the station itself. The OFDM signal generation unit (225) also maps D-BCH+, which can be decoded only by an LTE+ terminal, to all of the plurality of unit bands to produce a multiplexed transmission signal. When the terminal which has transmitted terminal capability information is an LTE+ terminal, a control unit (265) transmits a band movement indication which indicates changes in the reception band to that terminal.
Abstract:
A wireless communication apparatus, method, and system selectively utilize advantages of both centralized control and distributed control while suppressing cell searching time. FIG. 4(a) represents an example in which a P-BCH (Primary Broadcast Channel) and an S-SCH (Secondary Synchronization Channel) for centralized control and a P-BCH and an S-SCH for distributed control are frequency-divided, and the P-BCH and the S-SCH for the distributed control are transmitted to a distributed control resource. FIG. 4(b) represents an example in which a P-BCH and an S-SCH for the centralized control and a P-BCH and an S-SCH for the distributed control are time-divided, and the P-BCH and the S-SCH for the distributed control are transmitted to a centralized control resource. Since a relay station transmits the P-SCH (Primary Synchronization Channel) as a centralized control resource, a mobile station can specify sub-frame timing by using only the centralized control resource.
Abstract:
There are provided a communication device, a base station, a communication system, and a communication method that make it possible to yield a diversity effect by cooperative relay without involvement of disproportionateness in data received by an eNB even when one of parties has unsuccessfully exchanged data. After received an ACK signal from a repeater 1, a repeater 2 which has transmitted a NACK signal in procedure 7 transmits data S2 to the eNB by use of its own resource, thereby making its own resource available for the repeater 1 (the repeater 2 does not use its own resource, and the repeater 1 uses the resource of the repeater 2). In procedures 8, the repeater 1 has received the NACK signal from the repeater 2 and subsequently transmits data S1 to the eNB by use of its own resource. Subsequently, the repeater 1 which has received the MACK signal in procedure 9 determines that the resource of the repeater 2 is available and transmits data P1 to the eNB by use of the resource of the repeater 2. In procedure 10, the repeater 1 transmits previously-generated data P2 to the eNB by use of its own resource.