We consider space time block coded-continuous phase modulation (STBC-CPM), which has the advantages of both STBC and CPM at the same time. A weak point of STBC-CPM is that the normalized spectral efficiency (NSE) is limited by the orthogonality of the STBC and CPM parameters. The purpose of this study is to improve the NSE of STBC-CPM. The NSE depends on the transmission rate (TR), the bit error rate (BER) and the occupied bandwidth (OBW). First, to improve the TR, we adapt quasi orthogonal-STBC (QO-STBC) for four transmit antennas and quasi-group orthogonal Toeplitz code (Q-GOTC) for eight transmit antennas, at the expense of the orthogonality. Second, to evaluate the BER, we derive a BER approximation of STBC-CPM with non-orthogonal STBC (NO-STBC). The theoretical analysis and simulation results show that the NSE can be improved by using QO-STBC and Q-GOTC. Third, the OBW depends on CPM parameters, therefore, the tradeoff between the NSE and the CPM parameters is considered. A computer simulation provides a candidate set of CPM parameters which have better NSE. Finally, the adaptation of non-orthogonal STBC to STBC-CPM can be viewed as a generalization of the study by Silvester et al., because orthogonal STBC can be thought of as a special case of non-orthogonal STBC. Also, the adaptation of Q-GOTC to CPM can be viewed as a generalization of our previous letter, because linear modulation scheme can be thought of as a special case of non-linear modulation.

In order to realize multi-service in TDS-OFDM system, a novel multiplexing scheme based on space time block code is proposed along with the corresponding demultiplexing method with low complexity. Simulations show the presented scheme can not only achieve full diversity gain, but also effectively improve the system capacity.

This letter investigates the space-time block codes from quasi-orthogonal design as a tradeoff between high transmission rate and low decoding complexity. By studying the role orthogonality plays in space-time block codes, upper bound of transmission rate and lower bound of decoding complexity for quasi-orthogonal design are claimed. From this point of view, novel algorithms are developed to construct specific quasi-orthogonal designs achieving these bounds.

Efficient bi-directional multi-hop wireless networks based on MIMO algorithm or network coding have been proposed in recent papers. This paper proposes a new technique named as MIMO network coding, that is a combination of network coding and MIMO algorithm for multi-hop relay networks. By using MIMO network coding, co-channel interference cancellation and efficient bi-directional transmission can be realized simultaneously with lower complexity in multi-hop networks. Moreover, Space Time Block Code (STBC) MIMO transmission is also introduced to achieve higher reliability in MIMO network coding. It is confirmed from numerical analysis that the MIMO network coding with STBC achieves higher capacity and reliability than conventional schemes.

In this letter, a simple but effective antenna selection algorithm for orthogonal space-time block codes with a linear complex precoder (OSTBC-LCP) is proposed and compared with two conventional algorithms in temporally and spatially correlated fading channels. The proposed algorithm, which minimizes pairwise error probability (MinPEP) with an error codebook (EC) constructed from the error vector quantization, is shown to provide nearly the same performance of MinPEP based on all possible error vectors, while keeping the complexity close to that of antenna selection algorithm based on maximum power criterion (Maxpower).

We introduce a novel configuration for a multi-user Multiple-Input Multiple-Output (MIMO) system in mobile communication over fast fading channels using space-time block coding (STBC) and adaptive array. The proposed scheme adopts the simultaneous transmission of data and pilot signals which reduces control errors caused by delay of obtaining channel state information (CSI). Data and pilot signals are then encoded using a space-time block code and are transmitted from two transmit antennas. In order to overcome the fast fading problem, implementation of adaptive array using recursive least squares (RLS) algorithms is considered at the base station. Through computer simulation, it is shown that the proposed scheme in this way can overcome Doppler spread in higher frequencies and suppress co-channel interference up to N-1 users for N receiving antennas.

High Rate Space-Time Block Codes (HR-STBCs) with greater than 1 symbol/transmission and simple decoding schemes are proposed. The HR-STBC demonstrates 3 dB Eb/No gain at BER = 10-3 compared with the conventional STBC when three transmit antennas and two receive antennas are utilized.

We extend the differential space time block code (STBC) using nonconstant modulus constellations of two transmit antennas to four transmit antennas case. The proposed method obtains larger minimum Euclidean distances than those of conventional differential STBC with PSK constellations. We derive the symbol error rate (SER) performance of the proposed method and demonstrate the SER performance using computer simulations for both static and fast fading channels. For transmission rates greater than 2 bits/channel use and 3 bits/channel use, the proposed method outperforms the conventional differential STBC.