Radio communication apparatus and pilot symbol transmission method
A radio communication apparatus is disclosed that enables the influence of the feedback information on the channel capacity to be kept to the minimum without reducing the transmission efficiency of information by transmission of pilot symbol. In the apparatus, a delay dispersion measuring section ( 272 ) generates a delay profile using the received signal, and measures delay dispersion indicative of dispersion of delayed versions. A moving speed estimating section ( 274 ) estimates moving speed of a mobile station apparatus that transmits a pilot symbol based on the variation in reception power of the pilot symbol. An other-cell interference measuring section ( 276 ) measures other-cell interference caused by signals transmitted in cells except the cell to which the apparatus belongs. Corresponding to the delay dispersion, moving speed and other-cell interference, a pilot pattern information generating section ( 278 ) selects a pilot pattern such that placement of pilot symbol is optimal in a frame, and generates the pilot pattern information.
1. A transmitting apparatus that transmits pilot signals to a plurality of user equipment, the transmitting apparatus comprising:
a generator configured to generate a signal including pattern information indicating which pilot pattern among at least two pilot patterns is respectively assigned to each time slot of a plurality of time slots, each of the pilot patterns representing different densities of pilot signals arranged in mutually different patterns in at least one of the frequency domain and the time domain, the different densities of pilot signals corresponding to different proportions of pilot symbols, at least two of the time slots being assigned different pilot patterns from among the at least two pilot patterns; and
a transmitter configured to broadcast the signal including the pattern information indicating which pilot pattern among the at least two pilot patterns is respectively assigned to each time slot of the plurality of time slots to the plurality of user equipment, and to transmit the pilot signals according to the pattern information indicating which pilot pattern among the at least two pilot patterns is respectively assigned to each of the plurality of time slots.
2. The transmitting apparatus according to claim 1 , further comprising:
a selector configured to select the pilot pattern assigned to each time slot based on at least one of parameters concerning interference by multipath, parameters reflecting a propagation environment, and parameters reflecting a delay dispersion.
3. The transmitting apparatus according to claim 1 , further comprising:
a multiplexer configured to multiplex the pilot signals of the pilot patterns and user data according to the pattern information to generate a multiplexed signal, wherein:
the transmitter is configured to transmit the multiplexed signal.
4. A base station comprising the transmitting apparatus according to claim 1 .
5. A transmitting method of transmitting pilot signals from a transmitting apparatus to a plurality of user equipment, the transmitting method comprising:
generating a signal including pattern information indicating which pilot pattern among at least two pilot patterns is respectively assigned to each time slot of a plurality of time slots, each of the pilot patterns representing different densities of pilot signals arranged in mutually different patterns in at least one of the frequency domain and the time domain, the different densities of pilot signals corresponding to different proportions of pilot symbols, at least two of the time slots being assigned different pilot patterns from among the at least two pilot patterns;
broadcasting the signal including the pattern information indicating which pilot pattern among the at least two pilot patterns is respectively assigned to each time slot of the plurality of time slots to the plurality of user equipment; and
transmitting the pilot signals according to the pattern information indicating which pilot pattern among the at least two pilot patterns is respectively assigned to each of the plurality of time slots.
6. An integrated circuit that controls transmission of pilot signals to a plurality of user equipment, equipment, the integrated circuit comprising:
a generator configured to control a process of generating a signal including pattern information indicating which pilot pattern among at least two pilot patterns is respectively assigned to each time slot of a plurality of time slots, each of the pilot patterns representing different densities of pilot signals arranged in mutually different patterns in at least one of the frequency domain and the time domain, the different densities of pilot signals corresponding to different proportions of pilot symbols, at least two of the time slots being assigned different pilot patterns from among the at least two pilot patterns; and
a controller configured to control a process of broadcasting the signal including the pattern information indicating which pilot pattern among the at least two pilot patterns is respectively assigned to each time slot of the plurality of time slots to the plurality of user equipment, and transmitting the pilot signals according to the pattern information indicating which pilot pattern among the at least two pilot patterns is respectively assigned to each the plurality of time slots.