IEICE Transactions on Communications 

About: IEICE Transactions on Communications is an academic journal published by Institute of Electronics, Information and Communication Engineers. The journal publishes majorly in the area(s): MIMO & Orthogonal frequency-division multiplexing. It has an ISSN identifier of 0916-8516. Over the lifetime, 9244 publications have been published receiving 62163 citations. The journal is also known as: Transactions on communications & IEICE transactions.

Rate-compatible punctured convolutional codes (RCPC codes) and their applications

Abstract: The concept of punctured convolutional codes is extended by punctuating a low-rate 1/N code periodically with period P to obtain a family of codes with rate P/(P+l), where l can be varied between 1 and (N-1)P. A rate-compatibility restriction on the puncturing tables ensures that all code bits of high rate codes are used by the lower-rate codes. This allows transmission of incremental redundancy in ARQ/FEC (automatic repeat request/forward error correction) schemes and continuous rate variation to change from low to high error protection within a data frame. Families of RCPC codes with rates between 8/9 and 1/4 are given for memories M from 3 to 6 (8 to 64 trellis states) together with the relevant distance spectra. These codes are almost as good as the best known general convolutional codes of the respective rates. It is shown that the same Viterbi decoder can be used for all RCPC codes of the same M. the application of RCPC codes to hybrid ARQ/FEC schemes is discussed for Gaussian and Rayleigh fading channels using channel-state information to optimise throughput. >

Multi-Carrier CDMA in Indoor Wireless Radio Networks

Abstract: This paper examines a novel digital modulation/multiple access technique called Multi-Carrier Code Division Multiple Access (MC-CDMA) where each data symbol is transmitted at multiple narrowband subcarriers. Each subcarrier is encoded with a phase offset of 0 or π based on a spreading code. Analytical results are presented on the performance of this modulation scheme in an indoor wireless multipath radio channel. Introduction This paper examines the performance of a new spread spectrum transmission method called “MCCDMA” in an indoor wireless environment. MC-CDMA may be a suitable modulation technique in the indoor environment where the dispersive character of indoor propagation [1] allows for the exploitation of this technique. With MC-CDMA, each data symbol is transmitted over N narrowband subcarriers where each subcarrier is encoded with a 0 or π phase offset. If the number of and spacing between subcarriers is appropriately chosen, it is unlikely that all of the subcarriers will be located in a deep fade and consequently frequency diversity is achieved. As an MC-CDMA signal is composed of N narrowband subcarrier signals [2] each with a symbol duration, Tb, much larger than the delay spread, Td, an MC-CDMA signal will not experience significant intersymbol interference (ISI). Multiple access is achieved with different users transmitting at the same set of subcarriers but with spreading codes that are orthogonal to the codes of other users. Basic Principles of MC-CDMA The generation of an MC-CDMA signal can be described as follows. As shown in Fig. 1, a single data symbol is replicated intoN parallel copies. Each branch of the parallel stream is multiplied by one chip of a spreading code of length N and then binary phase-shift keying (BPSK) modulated to a subcarrier spaced apart from its neighboring subcarriers by F/Tb Hz whereF is an integer number. The transmitted signal consists of the sum of the outputs of these branches. For F = 1, this scheme is similar to performing Orthogonal Frequency Division Multiplexing (OFDM) [3] on a Direct-Sequence spread-spectrum signal [4]. Recently, there has been a growing interest on idea of combining OFDM and DS-CDMA [5] [6] [7] [8] [9]. Modern DSP methods make the implementation of MC-CDMA feasible and attractive. With F = 1, the transmit bandwidth is minimized. However, larger values of F may be desired to further increase the transmit bandwidth, i.e., to achieve a larger frequency diversity gain, without increasing the complexity in signal processing due to large spreading factors,N. The transmitted signal corresponding to the kth data bit of themth user ( am[k] ) is (1) sm t ( ) cm i [ ] am k [ ] 2πfct 2πi F Tb t + ( ) Tb t kTb − ( ) cos i 0 = N 1 − ∑ = cm i [ ] 1 1 , − { } ∈

Non-orthogonal Multiple Access (NOMA) with Successive Interference Cancellation for Future Radio Access

Abstract: SUMMARY This paper presents our investigation of non-orthogonal multiple access (NOMA) as a novel and promising power-domain user multiplexing scheme for future radio access. Based on information theory, we can expect that NOMA with a successive interference canceller (SIC) applied to the receiver side will offer a better tradeoff between system efficiency and user fairness than orthogonal multiple access (OMA), which is widely used in 3.9 and 4G mobile communication systems. This improvement becomes especially significant when the channel conditions among the non-orthogonally multiplexed users are significantly different. Thus, NOMA can be expected to efficiently exploit the near-far effect experienced in cellular environments. In this paper, we describe the basic principle of NOMA in both the downlink and uplink and then present our proposed NOMA scheme for the scenario where the base station is equipped with multiple antennas. Simulation results show the potential system-level