Abstract
Orthogonal frequency-division multiplexing with random multiple access (OFDRMA) is discussed for down-link communications, whereby a single base-station transmits information towards several active users. Current methods for down-link communication partition the frequency resources among the active users in an orthogonal fashion, i.e. a central unit (typically the base-station itself) dynamically allocates the resources such that each user is allocated a fixed and exclusive set of sub-bands (a.k.a. bins, or subcarriers). The task and overhead required for orchestrating the frequency sub-bands allocations among the users in an optimal fashion can be quite cumbersome, and typically involves increased computational complexity, latency and bandwidth resources. The main purpose we address in this paper is to avoid the task and overhead required in the state-of-the-art OFDM systems in both the base-station and the users, while sacrificing as little as possible in terms of users side error rate performance. This is of particular importance in multi-user multiple-input multiple-output systems, which become increasingly popular these recent years. In OFDRMA a user is assumed to be allocated with a predetermined, randomly selected frequency bins. A multi-antenna multi-user delivery approach is presented based on pre-coding and multi-cast transmission. It is shown to provide robustness against the forced randomness of the scheme. Simulation results are provided for demonstrating the performance attainable with OFDRMA and the proposed transmission scheme.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
Whenever \(\Vert * \Vert\) operates on a vector, it denotes the Euclidean norm of a vector.
Abbreviations
- OFDM:
-
Orthogonal frequency-division multiplexing
- OFDRMA:
-
Orthogonal frequency-division multiplexing with random multiple access
- MU-MIMO:
-
Multi-user multiple input multiple output
- QPSK:
-
Quadrature phase-shift keying
- Bin l :
-
Frequency sub-band l
- CSI:
-
Channel state information
- SVD:
-
Singular value decomposition
- BER:
-
Bit error rate
- SNR:
-
Signal to noise
- u :
-
Number of active users
- m :
-
Packet length
- \(\vartheta\) :
-
Number of transmit antennas
- \(\bar{X}_i\) :
-
The coded and modulated sequence that the base-station transmits toward the ith user
- n :
-
The length of \(\bar{X}_i\)
- \(\omega _i\) :
-
The square amplitude of the components of \(\bar{X}_i\)
- \(\phi _i\) :
-
The phase-shift used for the ith user
- \(B_i\) :
-
Bin-allocation vector for user i
- \(T^a_l\) :
-
The signal transmitted by the base-station on the ath antenna over frequency sub-band l
- \(R_{il}\) :
-
The signal received by the ith user on sub-band l
- \(g^a_{il}\) :
-
The path gain of sub-band l from the base-station ath antenna to user i
- \(c_l\) :
-
Multicast order on sub-band l
- \(v_{li}\) :
-
The (indexes of) the users, \(1 \le i \le c_l\), sharing the lth bin
- \(h^a_{il}\) :
-
The path gain of sub-band l from the base-station ath antenna to user \(v_{li}\)
- \(\sigma ^2\) :
-
The variance of noise samples \(n_{il}\)
- \({\mathfrak {F}}^\nu _l\) :
-
The transmit function on the base-station transmit antenna \(\nu\) and frequency bin l
- \(\varUpsilon\) :
-
Average energy constraint
- \(H_l\) :
-
A \(2 c_l \times 2 \vartheta\) matrix, calculated from the path gains, phase-shift and amplitude of all the users sharing the lth sub-band
- \(\bar{T}_l\) :
-
A length-\(2 \vartheta\) vector consisting of all the values transmitted by the base-station on bin l
- \(\bar{S}_l\) :
-
A length-\(2 c_l\) vector consisting of all the constellation points that the base-station needs to convey to each of the relevant users on bin l
- \(\bar{Q}_l\) :
-
A “normalized” (amplitude 1) version of \(\bar{S}_l\)
- \(\lambda\) :
-
Lagrange multiplier for NISR minimization under energy constraint
- \(G_l\) :
-
A \(2 c_l \times 2 \vartheta\) matrix containing all the path gains on the lth sub-band
- \(\omega\) :
-
The square amplitude of the components of \(\bar{X}_i\) for the uniform case
- \(\phi\) :
-
The phase-shift for the uniform case
References
Kineplex, a multi-carrier high frequency modem. Mosier and Clabaugh. (1957).
Chang, R. W. (1966). Synthesis of band-limited orthogonal signals for multi-channel data transmission. Bell System Technical Journal, 45(10), 1775–1796.
Saltzberg, B. R. (1967). ’Performance of an efficient parallel data transmission system. In IEEE Transactions on Communication Technology (Vol. COM-37, pp. 805–811).
Weinstein, S., & Ebert, P. (1971). Data transmission by frequency-division multiplexing using the discrete Fourier transform. IEEE Transactions on Communication Technology, 19(5), 628–634.
Cimini, L. J. (1985). Analysis and simulation of a digital mobile channel using orthogonal frequency division multiplexing. IEEE Transactions on Communications, 33(7), 665–675.
Kalet, I. (1989). The multitone channel. IEEE Transactions on Communications, 37(2), 119–124.
Bingham, J. A. C. (1990). Multicarrier modulation for data transmission: An idea whose time has come. IEEE Communications Magazine, 28(5), 5–14.
Vaezi, M., Ding, Z., & Poor, H. V. (2019). Multiple access techniques for 5G wireless networks and beyond. Berlin: Springer.
Nikopour, H., & Baligh, H. (2013). Sparse code multiple access. In Proceedings of IEEE 24th international symposium on personal indoor and mobile radio communication (pp. 332–336).
Nogueroles, R., Bossert, M., Donder, A., & Zyablov, V. (1998). Improved performance of a random OFDMA mobile communication system. In 48th IEEE vehicular technology conference, 1998. VTC 98 (Vol. 3, pp. 2502–2506).
Radiano, E., & Amrani, O. (2014). On disaster recovery in OFDMA environment. In 2014 IEEE 28th convention of electrical and electronics engineers in Israel (IEEEI) (pp. 1–4).
Balaban, P., & Salz, J. (1992). Optimum diversity combining and equalization in data transmission with application to cellular mobile radio—Part II: Numerical results. IEEE Transactions on Communications, 40, 895–907.
Spencer, Q. H., Swindlehurst, A. L., & M. Haardt. (2004). Zero-forcing methods for downlink spatial multiplexing in multiuser MIMO channels. In IEEE transactions on signal processing (Vol. 52, No. 2, pp. 461–471).
MacKay, D. J. C. Encyclopedia of sparse graph codes. http://www.inference.phy.cam.ac.uk/mackay/codes/data.html.
Richardson, T. J., & Urbanke, R. L. (2001). The capacity of low-density parity-check codes under message-passing decoding. IEEE Transactions on Information Theory, 47(2), 599–618.
Liu, W., Yang, L. L., & Hanzo, L. (2009). SVD-assisted multiuser transmitter and multiuser detector design for mimo systems. IEEE Transactions on Vehicular Technology, 58(2), 1016–1021.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Salomon, A.J., Salomon, B.G. & Amrani, O. Down-link OFDRMA communications. Wireless Netw 27, 103–116 (2021). https://doi.org/10.1007/s11276-020-02448-3
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11276-020-02448-3