摘要:
A guard section length detection method is disclosed. In the method, a guard section length detection method is used in an OFDM system. The OFDM symbol includes a data interval having a first length, and a guard section having a guard section length. The method detects a first symbol boundary and a second symbol boundary, and determines the guard section length based on a length between the first symbol boundary and the second symbol boundary.
摘要:
A guard section length detection method detects whether a preamble signal is received. A short preamble boundary is then detected, then detecting a frame boundary and detecting a guard section length. In the step of detecting the guard section length a second matched filter capable of processing 128 point data sets is detected. Four different 128 point data sets have a distance of 8 points, 16 points, 32 points, and 64 points respectively from the frame boundary to the second matched filter. Four signal correlation values are calculated for determining the guard section length.
摘要:
A method for compensating IQ imbalance is disclosed. First, an OFDM signal is received. The OFDM signal is translated into frequency domain, wherein the translated OFDM signal has N sub-carriers noted as Y(1)-Y(N). The IQ imbalance compensation factor is generated according to the k-th sub-carrier of the translated signal Y(k), the (N−k+2)-th sub-carrier of the translated signal Y(N−k+2), and the complex conjugates thereof.
摘要:
A method for compensating IQ imbalance is disclosed. First, an OFDM signal is received. The OFDM signal is translated into frequency domain, wherein the translated OFDM signal has N sub-carriers noted as Y(1)-Y(N). The IQ imbalance compensation factor is generated according to the k-th sub-carrier of the translated signal Y(k), the (N−k+2)-th sub-carrier of the translated signal Y(N−k+2), and the complex conjugates thereof.
摘要:
An adaptive channel estimator for estimating channel frequency responses when receiving OFDM symbols. The adaptive channel estimator comprises a channel estimator and a channel tracking module. The channel estimator generates one first channel frequency response for each OFDM symbol when operated in the first mode, and generates the channel frequency responses of a second channel frequency response for every N-th OFDM symbols when operated in the second mode, wherein N is a constant integer exceeding one and j is a non-negative integer. The channel tracking module indicates a channel status, and controls the channel estimator to operate in a first mode or a second mode according to the channel status.
摘要:
A guard section length detection method detects whether a preamble signal is received. A short preamble boundary is then detected, then detecting a frame boundary and detecting a guard section length. In the step of detecting the guard section length a second matched filter capable of processing 128 point data sets is detected. Four different 128 point data sets have a distance of 8 points, 16 points, 32 points, and 64 points respectively from the frame boundary to the second matched filter. Four signal correlation values are calculated for determining the guard section length.
摘要:
A channel information feedback method for multi-antenna system, and a wireless communication device using the same method are provided. The proposed method could reduce feedback overhead for multiple-input multiple-output (MIMO) wireless channel information, and is based on compressive sensing technique. Prior to sending back channel information, a receiver estimates the channel and multiplies the vectorized channel with a random matrix to generate compressed feedback content. Upon receiving the compressed feedback content at a transmitter, the channel information could be restored with signal recovery algorithms of compressive sensing technique. In the other embodiment, the proposed method further adaptively adjusts compression ratio of the compressed feedback content in accordance to the prevailing channel quality. Further, for slow-varying MIMO channels, there is proposed another channel information feedback method which switches between a fixed spasifying-basis and a signal-dependent sparsifying-basis.
摘要:
A subcarrier allocation method for use by a transmitter, the transmitter being configured to, when transmitting first and second data streams, allocate pilot symbols for the first and second data streams to subcarriers, such that a first plurality of subcarriers carry the pilot symbols for the first data stream and a second plurality of subcarriers carry the pilot symbols for the second data stream. The method includes allocating, when the transmitter transmits the first data stream but does not transmit the second data stream, the second plurality of subcarriers to carry no formation or information relating to the first data stream.
摘要:
A progressive parallel interference canceller (PPIC) and a method and a receiver thereof are illustrated. The PPIC reconstructs each subchannel interference reconstruction signal through several iterations and subtracts the corresponding subchannel interference reconstruction signal from each subchannel frequency-domain reception signal to obtain a subchannel frequency-domain signal. Thereby, according to the present disclosure, inter-channel interference can be cancelled without re-performing channel coding or estimating the signal to noise ratio (SNR) or frequency offset.
摘要:
A wireless communication method implemented in a communication system may include receiving a data sequence to be permuted, and obtaining information associated with the data sequence to be permuted, the information containing at least a length of the data sequence and a sampling spacing for permuting the data sequence. The method may also include identifying a first portion of the data sequence having a first number of adjacent data items, and a second portion of the data sequence having a second number of adjacent data items. The method may also include accessing the first number of data items from the first portion at the sampling spacing, and placing the accessed first number of data items into a predetermined number of sub-blocks included within a permuted data sequence to be generated based on the received data sequence. The method may further include inserting each of the second number of data items into an end position of one of the sub-blocks within the permuted data sequence, and outputting the permuted data sequence.