Analysis of the Frequency Offset Effect on Zadoff–Chu Sequence Timing Performance

Hua, Min; Wang, Mao; Yang, Kristo Wenjie; Zou, Kingsley Jun

doi:10.1109/tcomm.2014.2364597

Cited by 68 publications

(38 citation statements)

References 21 publications

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“…Denote byP (n) a modulated version of P (n) with carrier frequency ∆f i , i.e.P (n) = P (n)e j2π∆finT b , ∀n ∈ {0, N zc − 1}, where T b is the bit duration. Taking cross correlation of P (n) with P (n), one sees the peak location changes periodically between −⌊N zc /2⌋ and ⌊N zc /2⌋, as discussed in [17]. Given T b and N zc as characteristics of the system, position of shifted peak can be derived as a function ∆f i , denoted by Q(∆f i ), as depicted in Fig.…”

Section: Processing Of Detected Peaksmentioning

confidence: 98%

Grant-Free Radio Access for Short-Packet Communications over 5G Networks

Azari

Popovski

Miao

et al. 2017

GLOBECOM 2017 - 2017 IEEE Global Communications Conference

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Radio access management plays a vital role in delay and energy consumption of connected devices. The radio access in existing cellular networks is unable to efficiently support massive connectivity, due to its signaling overhead. In this paper, we investigate an asynchronous grant-free narrowband data transmission protocol that aims to provide low energy consumption and delay, by relaxing the synchronization/reservation requirement at the cost of sending several packet copies at the transmitter side and more complex signal processing at the receiver side. Specifically, the timing and frequency offsets, as well as sending of multiple replicas of the same packet, are exploited as form of diversities at the receiver-side to trigger successive interference cancellation. The proposed scheme is investigated by deriving closed-form expressions for key performance indicators, including reliability and battery-lifetime. The performance evaluation indicates that the scheme can be tuned to realize long battery lifetime radio access for low-complexity devices. The obtained results indicate existence of traffic load regions, where synchronous access outperforms asynchronous access and vice versa.

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Section: Processing Of Detected Peaksmentioning

confidence: 98%

Grant-Free Radio Access for Short-Packet Communications over 5G Networks

Azari

Popovski

Miao

et al. 2017

GLOBECOM 2017 - 2017 IEEE Global Communications Conference

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“…In order to represent the property of ZC codes, we take into consideration one CFO affected ZC code, which is shown in [14], [15] that…”

Section: ) Initial Detectionmentioning

confidence: 99%

“…When correlating a CFO affected ZC code with the local one, besides the main correlation peak, false correlation peaks also take place. In [14], [15], it is mathematically derived that the cyclic-shift of a CFO affected ZC code corresponds to its root value, which facilitates the determination of locations of false correlation peaks. A restricted set of ZC codes for bearing the impact of CFOs is designed in [16], [17] by taking into account cyclicshifts which result because of CFOs.…”

Section: Introductionmentioning

confidence: 99%

A Multiuser Detection Algorithm for Random Access Procedure With the Presence of Carrier Frequency Offsets in LTE Systems

Wang

Ren

2015

IEEE Trans. Commun.

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In the LTE system, uplink synchronization can be established through the random access channel, by which timing and frequency offsets between transceivers can be estimated and adjusted. As the single carrier frequency division multiple access (SC-FDMA) structure is utilized in LTE uplink, preambles for the random access channel should be generated and detected in the transform-domain at user equipments and the base station, respectively. However, in available literature, an explicit transformdomain signal model with respect to timing and frequency offsets has not been provided, and the impact of frequency offsets on the transform-domain signal is not analyzed either. Therefore, suffering from unknown interference among multiple user equipments, existing multiuser detection algorithms provide unsatisfied multiuser detection and estimation performance. In this paper, an explicit transform-domain signal model is first derived with respect to both timing and frequency offsets. The characteristic of transform-domain frequency offsets is then analyzed, which indicates that transform-domain frequency offsets behave totally different with time-domain frequency offsets. After that, a multisteps hybrid multiuser detection algorithm is proposed to improve the multiuser detection and estimation performance, and the Cramër-Rao bound to the accuracy of parameters estimation for the random access procedure is finally obtained. Simulation results show that the proposed algorithm is able to significantly improve the multiuser detection and estimation performance compared to existing ones.Index Terms-long term evolution, random access procedure, multiuser detection and estimation, carrier frequency offset. 0090-6778 (c)

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“…Along with aforementioned schemes and extensive pilot contamination elimination literature has not focused on uplink pilot sequence design or selection features and such contributions are limited in the literature, e.g., [13] and [14], where uplink pilot sequences in neighboring cells are treated as noise. Anzhong et al [13] proposed to phase shift a given Zadoff-Chu (ZC) sequence [15] among multiple cells and calculate the required phase shift to be used in each cell. Hien et al [14] proposed a greedy sequence assignment algorithm, where the sequences are allowed to take random values and are not chosen from a predefined set of sequences.…”

Section: Introductionmentioning

confidence: 99%

“…In fact, if the periodic autocorrelation of a ZC sequence provides a single peak at the zero lag, the periodic correlation of the same sequence against its cyclic shifted replica provides a peak at a lag CS L , where CS L is the number of samples of the cyclic shift. This creates a zero-correlation zone (ZCZ) between the two sequences [15]. To make pilot sequences orthogonal across the network, the orthogonal codes are used.…”

Section: Introductionmentioning

confidence: 99%

Design of Orthogonal Uplink Pilot Sequences for TDD Massive MIMO under Pilot Contamination

Memon¹,

Chen²,

Yin³

2017

JCM

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-Massive MIMO has been acknowledged as a promising technology to counter the demand for higher data capacity for wireless networks in 2020 and beyond. However, each Base Station (BS) requires good enough knowledge of Channel State Information (CSI) on both the uplink and the downlink as massive MIMO relies on spatial multiplexing. In Time Division Duplex (TDD) massive MIMO systems, this CSI is acquired using channel reciprocity. However, the use of nonorthogonal uplink pilot sequence due to limited coherence time leads to pilot contamination in TDD massive MIMO systems that results in inter-cell interference in the downlink data transmission. This paper proposes a design of orthogonal uplink pilot sequences for multi-cell TDD massive MIMO systems. We propose to use Zadoff-Chu Pilot Sequences (ZCPS) and eliminate pilot contamination during channel estimation process. In the proposed design, each BS is assigned with a specific orthogonal code and the set of ZCPS is multiplied element-wise at each BS with BS-specific orthogonal code to generate orthogonality among pilot sequences across neighboring cells. The proposed design eliminates pilot contamination during channel estimation process thus achieves significant sum-rate gains as verified by the simulation results.Index Terms-Massive MIMO, channel state information, pilot contamination, Zadoff-Chu, orthogonal codes  , where  is the length of the training sequences, which is assumed to be equal to

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Analysis of the Frequency Offset Effect on Zadoff–Chu Sequence Timing Performance

Cited by 68 publications

References 21 publications

Grant-Free Radio Access for Short-Packet Communications over 5G Networks

Grant-Free Radio Access for Short-Packet Communications over 5G Networks

A Multiuser Detection Algorithm for Random Access Procedure With the Presence of Carrier Frequency Offsets in LTE Systems

Design of Orthogonal Uplink Pilot Sequences for TDD Massive MIMO under Pilot Contamination

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