Compensation of Transmitter IQ Imbalance in Multi-User Hybrid Beamforming Systems

Mahendra, Rachit; Mohammed, Saif Khan; Mallik, Ranjan K.

doi:10.1109/access.2021.3094560

Cited by 10 publications

(3 citation statements)

References 51 publications

(111 reference statements)

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“…Firstly, the sampled signal is processed using the Gram-Schmidt orthogonalization procedure (GSOP). This procedure is utilized to orthogonalize the received signals, reducing interference and improving signal quality [24]. Subsequently, fixed dispersion coarse equalization techniques are applied to compensate for dispersion effects introduced during transmission.…”

Section: Digital Signal Processing Algorithmsmentioning

confidence: 99%

Investigation of IEEE 802.16e LDPC Code Application in PM-DQPSK System

Xue,

Li,

Zhang

et al. 2024

Electronics

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With the development of the Internet and information technology, optical fiber communication systems need to meet people’s information demand for large capacity and high speed. High-order phase modulation and channel multiplexing can improve the capacity and data rate of optical fiber communication systems, but they also bring the problem of bit error. To improve the transmission quality and reliability of optical fiber communication systems, forward error correction (FEC) coding techniques are commonly used, which serve as the fundamental approach to enhance the quality and reliability of fiber optic communication systems, ensuring that the received data remain accurate and reliable. The FEC in optical fiber communication systems is divided into three generations. The first generation FEC is mainly hard decision codewords, represented as RS code. The second generation FEC is mainly cascaded code, which stands for interleaved cascaded code. The third generation of FEC mainly refers to soft decision codes, which are represented as low-density parity-check (LDPC) codes. As a kind of FEC, LDPC codes stand out as pivotal contributors in the field of optical communication and have gained remarkable attention due to exceptional error correction performance and low decoding complexity. Based on IEEE802.16e standard, LDPC code with specific code length and rate is compiled and simulated in MATLAB and VPItransmissionMaker 10.1 and successfully incorporated into polarization multiplexed differential quadrature phase shift keying (PM-DQPSK) coherent optical transmission system. The simulation results indicate that the bit error rate (BER) can be reduced to 10−3 when the optical signal-to-noise ratio (OSNR) reaches 14.2 dB, and the BER experiences a reduction by nearly three orders of magnitude when the OSNR is 17.2 dB. These findings underscore the efficacy of LDPC codes in significantly improving the performance of optical communication systems, particularly in scenarios demanding robust error correction capabilities. This study provides valuable, significant results regarding the potential of LDPC codes for enhancing the reliability of optical transmission in real-world applications.

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Section: Digital Signal Processing Algorithmsmentioning

confidence: 99%

Investigation of IEEE 802.16e LDPC Code Application in PM-DQPSK System

Xue,

Li,

Zhang

et al. 2024

Electronics

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“…The IQ imbalance at the Tx of UEs in mMIMO HB UL system leads to finite ceiling of achievable sum-rate even at higher SNR. Introducing ZF techniques at the BS can compensate for undesirable IQ imbalance under different channel conditions [39].…”

Section: Literature Reviewmentioning

confidence: 99%

Hybrid Beamforming in 5G NR Networks Using Multi User Massive MIMO at FR2 Frequency Bands

Dilli

2022

Wireless Pers Commun

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The current Sub 6 GHz band is highly occupied and unable to meet the demands of future wireless data traffic. As the millimeter wave technology is a promising way of enhancing the performance of next-generation wireless networks, it is essential to explore FR2 frequency bands. Massive Multiple-Input Multiple Output (mMIMO) technology has been introduced to improve the capacity and coverage of 5G wireless networks. Hybrid beamforming (HB) is an efficient technique to improve the channel gain and minimize the interference at reasonable complexity. The aim of HB in mMIMO systems is to maximize the sum rate that can approach the fully-digital beamforming system performance. Combination of mMIMO systems, mmWave, and HB techniques achieve higher data rates and cell coverage in 5G wireless networks. It mitigates the hardware complexity, energy consumption, and cost as number of required radio-frequency chains at base station gets minimized. In this paper, we have investigated the performance of a multi user-mMIMO HB system at 28, 39 GHz of FR2 frequency bands as well as at 66 GHz by analyzing the effect of changing variables that include the number of users, transmitting and receiving antennas, and the type of modulation. Simulation results include RMS values of error vector magnitude (EVM) that gives quantitative analysis and receive constellation of the equalized symbols that shows qualitative analysis. EVM is computed for different scenarios and it is used as an indicator of performance to assess the suitable design configuration of mMIMO system.

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“…In ref. [21], the authors study the uplink multi-user HBF systems and propose a zero-forcing (ZF) based transmitter IQI compensation algorithm to mitigate the undesired effects of transmitter IQI. To achieve the performance of an IQI-free system, ref.…”

Section: Introductionmentioning

confidence: 99%

A leakage‐based hybrid beamforming design for multi‐user mmWave massive MIMO systems

2022

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In massive multiple-input multiple-output systems, hybrid beamforming (HBF) is an attractive technique due to its excellent tradeoff between system performance and hardware implementation cost. In this paper, the signal-to-leakage-plus-noise ratio is considered as the optimization criterion and investigate the HBF design for multi-user millimetre-wave massive multiple-input multiple-output systems. To overcome the difficulty of solving the multi-variable design problem, a novel two-stage HBF scheme to optimize the analogue and digital beamformers are proposed. In particular, an orthogonal matching pursuit-based method and a joint design method are introduced respectively to find the solution in the analogue stage. Then, in the digital stage, the digital precoder and combiner are designed to suppress the inter-user interference plus noise, aiming at maximizing the sum-signal-toleakage-plus-noise ratio of multi-user systems. Simulation results show that the proposed HBF scheme with lower complexity can achieve superior performance over the existing HBF schemes. Moreover, it is also indicated that the performance of the HBF scheme remains strong even with the imperfect channel state information.

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Compensation of Transmitter IQ Imbalance in Multi-User Hybrid Beamforming Systems

Cited by 10 publications

References 51 publications

Investigation of IEEE 802.16e LDPC Code Application in PM-DQPSK System

Investigation of IEEE 802.16e LDPC Code Application in PM-DQPSK System

Hybrid Beamforming in 5G NR Networks Using Multi User Massive MIMO at FR2 Frequency Bands

A leakage‐based hybrid beamforming design for multi‐user mmWave massive MIMO systems

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