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In this paper, we consider multi-carrier systems with multiple transmit antennas under a power balancing constraint. Applying transmit antenna selection and discrete rate adaptive modulation using M-ary quadrature amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal antenna selection scheme in terms of maximum spectral efficiency where all the possible...
Adaptive coded modulation (ACM) is a key technique to increase spectral as well as power efficiency for orthogonal frequency division multiplexing (OFDM) systems. In this paper, an efficient rate adaptive low density parity check (LDPC) coded modulation (RALCM) algorithm is proposed, which maximizes the payload rate for OFDM systems under the constraint of the given transmit power and the target bit...
A conventional OFDM system often poses a stringent linearity requirement to the transmitter, especially the radio-frequency power amplifier (RFPA), to maintain its bit error rate (BER). As a result, the output power from a RFPA is often limited, thus, the communication distance is compromised. With the deployment of WiMAX (IEEE 802.16), which is targeting at the mobile market, the communication distance...
This paper presents a joint adaptive modulation and coding (AMC) scheme, which exploits the coherence bandwidth of the wireless channel to divide the transmitted frame into independent sub-channels that correspond to the channel coherence bandwidth. This strategy is implemented for orthogonal frequency division multiplexing (OFDM) systems with channel state information (CSI) feedback. Low density...
The transmit adaptation is a key technique to realize the full potentials of orthogonal frequency-division multiplexing (OFDM) systems. In this paper, we first present a new channel state information (CSI) model in order to save the reverse channel spectrum. By using clustering and interpolation according to the correlation between subcarriers, the estimation of CSI is obtained at the transmitter...
A power spectral density constrained adaptive modulation with frequency spreading orthogonal frequency division multiplexing (OFDM) scheme is proposed. Our objective is to improve the overall throughput under target packet-error-rate (PER) for OFDM transmission. We investigated the performance of a coded adaptive modulation scheme with and without bit interleaver and apply the results to determine...
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