OFDM transmitting and receiving apparatus and OFDM transmitting and receiving method
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiroaki Sudo, Kimihiko Ishikawa
Life of this patent
Estimating the term…
Abstract
An average value of reception power of subcarriers A to D is calculated by a control circuit 162, and the average value is divided by envelops of received signals of subcarriers A to D, respectively, so as to calculate a coefficient signal of each subcarrier. Multipliers 106 to 109 multiply transmitting signals of subcarriers A to D output from mapping circuits 102 to 105 by the coefficient signals, respectively. Whereby, power between the subcarriers at a reception time can be maintained substantially constant so as to improve an error rate characteristic.
Claims22
An OFDM transmitting and receiving apparatus comprising:
- reception power measuring means for measuring reception power of a signal received from a partner station of each subcarrier;
- coefficient calculating means for calculating a coefficient for each subcarrier based on the measured reception power;
- and
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting.
A base station apparatus comprising an OFDM transmitting and receiving apparatus, wherein said OFDM transmitting and receiving apparatus comprises:
- reception power measuring means for measuring reception power of a signal received from a partner station of each subcarrier;
- coefficient calculating means for calculating a coefficient of respective subcarriers based on the measured reception power;
- and
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting.
A communication terminal apparatus comprising an OFDM transmitting and receiving apparatus, wherein said OFDM transmitting and receiving apparatus comprises:
- reception power measuring means for measuring reception power of a signal received from a partner station of each subcarrier;
- coefficient calculating means for calculating a coefficient of respective subcarriers based on the measured reception power;
- and
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting.
An OFDM transmitting and receiving method comprising the steps of:
- measuring reception power of a signal received from a partner station of each subcarrier;
- calculating a coefficient of respective subcarriers based on the measured reception power;
- multiplying a transmitting signal to said partner station of each subcarrier by said coefficient;
- and
- transmitting said transmitting signal.
An OFDM transmitting and receiving method comprising the steps of:
- calculating an average value of reception power of each subcarrier;
- selecting a shift amount by a ratio between said average value and reception power of each subcarrier;
- passing a transmitting signal of each subcarrier through a bit shift circuit of said selected shift amount;
- and
- transmitting said transmitting signal.
An OFDM transmitting and receiving apparatus that controls transmitting power for each subcarrier based on reception power comprising:
- coefficient calculating means for calculating a coefficient for each subcarrier based on the reception power of signals received from a partner station of each subcarrier;
- and
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting.
An OFDM transmitting and receiving apparatus comprising:
- reception means for receiving a signal transmitted from a partner station of each subcarrier;
- coefficient calculating means for calculating a coefficient for each subcarrier based on the received signal power of each subcarrier;
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting;
- and
- transmission means for transmitting the weighted transmitting signal of each subcarrier to said partner station.
An OFDM transmitting and receiving apparatus comprising:
- A/D conversion means for receiving a signal transmitted from a partner station to convert into a digital signal;
- Fourier transform means for performing Fourier transform on a received signal output from said A/D conversion means to extract a received signal of each subcarrier;
- coefficient calculating means for calculating a coefficient for each subcarrier based on reception power of the received signal of each subcarrier;
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting;
- inverse Fourier transform means for performing inverse Fourier transform on the weighted transmitting signal of each subcarrier;
- and
- D/A conversion means for converting the transmitting signal output from said inverse Fourier transform means into an analog signal to transmit to said partner station.
An OFDM transmitting and receiving apparatus comprising:
- reception power measuring means for measuring reception power of a signal received from a partner station of each subcarrier;
- coefficient calculating means for calculating a coefficient such that reception power of each subcarrier can be maintained substantially constant at the time signals are received by the partner station, based on the measured reception power;
- and
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting.
An OFDM transmitting and receiving apparatus that controls transmitting power for each subcarrier based on reception power comprising:
- coefficient calculating means for calculating a coefficient such that reception power of each subcarrier can be maintained substantially constant at the time signals are received by the partner station;
- and
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting.
An OFDM transmitting and receiving apparatus comprising:
- reception means for receiving a signal transmitted from a partner station of each subcarrier;
- coefficient calculating means for calculating a coefficient such that reception power of each subcarrier can be maintained substantially constant at the time signals are received by the partner station, based on the received signal power of each subcarrier;
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting;
- and
- transmission means for transmitting the weighted transmitting signal of each subcarrier to said partner station.
An OFDM transmitting and receiving apparatus comprising:
- A/D conversion means for receiving a signal transmitted from a partner station to convert into a digital signal;
- Fourier transform means for performing Fourier transform on a received signal output from said A/D conversion means to extract a received signal of each subcarrier;
- coefficient calculating means for calculating a coefficient such that reception power of each subcarrier can be maintained substantially constant at the time signals are received by the partner station, based on reception power of the received signal of each subcarrier;
- a plurality of transmitting signal weighting means for multiplying a transmitting signal to said partner station of each subcarrier by said coefficient to perform weighting;
- inverse Fourier transform means for performing inverse Fourier transform on the weighted transmitting signal of each subcarrier;
- and
- D/A conversion means for converting the transmitting signal output from said inverse Fourier transform means into an analog signal to transmit to said partner station.
Dependencies are inferred from the claim text.