摘要:
In a TDS-OFDM communications system, within a frame time, a transmitted signal comprising a preamble, a downlink sub-frame, and an uplink sub-frame. Within the downlink sub-frame, interposed between sub-frames are guard intervals comprising known sequences. The known sequences are used for an estimation of a received power. A method comprising the step of using a guard sequence in a guard interval of OFDM symbols of the received TDS-OFDM signals in the downlink to estimate a received signal power or an interference power is provided.
摘要:
In a TDS-OFDMA communications system, a frame structure comprising: a frame such that within a frame time, a transmitted signal comprising a preamble, a downlink sub-frame, and an uplink sub-frame; and interposed between OFDM symbols are guard intervals comprising known sequences being used for an estimation of a received power.
摘要:
In an OFDM system having pseudo-noise (PN) sequences as guard intervals, a method for channel estimation and equalization is provided. The method comprising the steps of: providing a frequency equalization scheme; providing a time domain filter; and combining the frequency equalization with time-domain filter, thereby a time lag effect is taken into consideration for the channel estimation and equalization.
摘要:
In an orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) wireless communication system where both a transmitter and a receiver include a plurality of antennas, a method comprising the steps of: a receiver using at least one pseudo noise (PN) to associate desired information relating to a received symbol; and transforming the correlated information into frequency domain.
摘要:
A circuit structure has a channel estimator adapted to receive an input, an equalizer adapted to receive the input and generate an equalized output, and an equalizer training block adapted to receive estimated channel condition information, and provide a set of trained coefficients to the equalizer. The equalized output is used by the channel estimator for at least one subsequent channel estimation. The channel estimator, the equalizer, and the equalizer training block are looped together.
摘要:
In a TDS-OFDM communications system, within a frame time, a transmitted signal comprising a preamble, a downlink sub-frame, and an uplink sub-frame. Within the downlink sub-frame, interposed between sub-frames are guard intervals that have known sequences positioned therein. The known sequences are used for an estimation of a received power. A method comprising the step of using a guard sequence in a guard interval of OFDM symbols of the received TDS-OFDM signals in the downlink or the uplink to estimate a received signal power and using the estimated signal power to calculate a CINR is provided.
摘要:
Method and system for adaptively estimating and compensating for phase noise error in a received signal s(t;data). A plurality of transmission parameter symbol (TPS) sets, each with a representative TPS group frequency, are incorporated in the signal before transmission. Received channel response amplitudes are analyzed to select a particular TPS frequency group, and inverse Fourier transforms, N(t) and D(t), are computed for these chosen signals. A complex ratio, r(t)=N(t)/D(t), is computed and used to determine a phase angle φ(t). A phase noise error compensated, time domain signal, equal to exp{−jφ(t)}·s(t−Δt(delay);data) is provided.
摘要:
In an orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) wireless communication system, a method is provided for channel estimation using a sub-space method suitable for computer implementation. The system has both a transmitter and a receiver including a plurality of antennas. The method comprising the step of: a receiver using at least one pseudo noise (PN) to correlate desired information relating to a received symbol; transforming the correlated information into frequency domain; and performing channel estimation using a sub-space method suitable for computer implementation.
摘要:
In a TDS-OFDM system, frequency offset estimate provided. A method for estimating a frequency offset comprising the step of correlating a known PN sequence with a received signal.
摘要:
In a TDS-OFDM system, a method for transmission is provided. The method comprises the step of: adjusting a PN sequence length, whereby a required performance is maintained. The adjusting step comprises increasing, decreasing, or keep unchanging the PN sequence length.