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

Abstract

SUMMARYThis 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 throughput gains of NOMA relative to OMA.

Dynamic Fractional Frequency Reuse Diversity Design for Intercell Interference Mitigation in Nonorthogonal Multiple Access Multicellular Networks

“…In recent years, many NOMA schemes have been devised such as interleave-division multiple access (IDMA) [7], low-density spreading CDMA (LDS-CDMA) [8], pattern-division multiple access (PDMA) [9][10][11][12][13][14], sparsecode multiple access (SCMA) [15][16][17], multiuser sharing access (MUSA) [18][19][20], bit-division multiplexing (BDM) [21], low-density spreading OFDM (LDS-OFDM) [22], resource-spread multiple access (RSMA) [23,24], interleavegrid multiple access (IGMA) [25], multiuser bit-interleaved coded modulation with iterative decoding (MU-BICM-ID) [26], and power domain nonorthogonal multiple access (PD-NOMA) [5,[27][28][29][30][31][32].…”

“…PD-NOMA is considered in which users are distinguished on the basis of allocated transmit power on a shared resource [28]. Power allocation in NOMA is carried out considering the detection process via SIC at the receiver; hence, a user with a poor channel gain, i.e., cell edge (CE) user, is allocated a higher power and a lower power is assigned to the user with a better channel gain, i.e., cell center (CC) user [28].…”

“…Power allocation in NOMA is carried out considering the detection process via SIC at the receiver; hence, a user with a poor channel gain, i.e., cell edge (CE) user, is allocated a higher power and a lower power is assigned to the user with a better channel gain, i.e., cell center (CC) user [28]. CE users will be the ones most affected by the ICI as they will have to cancel out any possible spillover signals intended for CE users of adjacent cells.…”

“…CE users will be the ones most affected by the ICI as they will have to cancel out any possible spillover signals intended for CE users of adjacent cells. Higher powers are allocated to CE users to ensure throughput as well as sufficient received power at the base station (BS) for detection [28]. Both CC and CE users are then mapped onto respective frequency resource blocks (RBs).…”

Four time windows averaging channel estimation with real and imaginary TFI pilot signals for OFDM

“…In the typical techniques with the orthogonally, orthogonal frequency division multiplexing (OFDM) is studied widely [1,2]. OFDM achieves high capacity transmissions by using multicarrier systems and has been adopted in many standards such as wireless local area network (WLAN), digital broadcasting, and mobile communication systems.…”