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Recently, some orthogonal multiple access schemes are utilized in return channels. However, in the field of wireless communication, as the number of users increases, the orthogonal resources are difficult to meet the explosive demand of access. For this reason, some non-orthogonal multiple access (NOMA) schemes have been proposed to solve the key problem of massive connectivity. In this paper, we...
In this paper, an iterative zero forcing (IZF) detection scheme for generalised spatial modulation (GSM) is proposed to provide superior performance of bit error rate (BER) compared with other linear detection scheme, such as zero forcing (ZF) detection and minimum mean square error (MMSE) detection. Comparing to the optimal maximum likelihood (ML) detection, the proposed IZF detection also reduces...
For digital terrestrial television broadcasting (DT-TB) systems, orthogonal frequency division multiplexing (OFDM) technique is considered to be an effective method to combat the frequency selective channel cause by multi-path effect. In the single frequency network (SFN) scenario, Alamouti space frequency block coding (SFBC) is introduced to provide spatial diversity gain and improve the link stability...
A novel extension of the traditional generalized spatial modulation (GSM) is proposed to improve the spectral efficiency of GSM. In the traditional GSM scheme, the symbols transmitted by different active antenna elements are the same during each symbol period and the number of states of each antenna element is only two i.e. on and off. The two-state constraint over the antenna in GSM is however found...
In this paper, we propose a time-domain oversampled receiver for orthogonal frequency division multiplexing (OFDM) in underwater acoustic communication. Without changing the structure of the transmitter, significant gains are acquired by time- domain oversampling at the receiver. Using time- domain oversampling, the energy of transmitted symbols is concentrated on the first N subcarriers, while additive...
Recently, compressive sensing (CS) algorithms have been adopted to improve the accuracy of channel estimation for wide-band wireless communication systems. Since the wireless channel is usually time and frequency doubly selective fading, the performance of CS based channel estimation is limited by the estimation accuracy of the channel's sparsity level. In this paper, an adaptive subspace pursuit...
In this paper, an iterative receiver with Turbo equalization and soft demapping is proposed for high data rate communication in multipath channels. Minimum mean square error (MMSE) equalization is adopted to avoid noise enhancement. With the assumption that the distribution of estimated symbols is Gaussian distribution, log likelihood ratios (LLR) of encoded bits are obtained with soft demapping....
In this article, a novel scheme is presented for single-carrier wireless burst transmission. The frame format is proposed, which contains training sequence and some data sub-blocks with guard intervals. The training sequence is used for carrier recovery and channel estimation. The unique words are inserted between data sub-blocks as guard intervals to eliminate inter symbol interference (ISI). The...
Time domain synchronous OFDM (TDS-OFDM) has higher spectral efficiency than cyclic prefix OFDM (CP-OFDM), but suffers from severe performance loss over fast fading channels. In this paper, a novel transmission scheme called time-frequency training OFDM (TFT-OFDM) is proposed. The time-frequency joint channel estimation for TFT-OFDM utilizes the time-domain training sequence without interference cancellation...
To reduce the complexity of existing transmit diversity solutions for time domain synchronous OFDM (TDS-OFDM), a simple transmit diversity scheme is proposed in this paper. The space shifted constant amplitude zero autocorrelation (CAZAC) sequence is used for time-domain channel estimation. Two types of flexible frame structures are investigated for cyclicity reconstruction of the received inverse...
The existing transmit diversity schemes for time domain synchronous OFDM (TDS-OFDM) is only suitable either for fast time-varying but weakly frequency-selective channels, or strongly frequency-selective but slow fading channels. In this paper, the space-time shifted constant amplitude zero autocorrelation (CAZAC) sequence based TDS-OFDM transmit diversity scheme is proposed for doubly selective channels...
When adopting transmit diversity in Time Domain Synchronous Orthogonal Frequency Division Multiplex (TDS-OFDM) system, the pseudo noise (PN) sequence from different transmit antennas will interfere with each other, so the receiver can't estimate the channel impulse response (CIR) correctly. In this paper, two frame structures with different PN sequence designs for transmit diversity are proposed....
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...
Nordstrom-Robinson (NR) code followed by 4 quadrature-amplitude modulation (4QAM) mapping is one of the working modes in the Chinese digital television terrestrial broadcasting (DTTB) standard, where the outer code is a low-density parity-check (LDPC) code. Since LDPC decoders usually accept soft rather than hard inputs for better error performance, soft NR decoders are highly recommended. In this...
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