Protocol Sequences for the Multiple-Packet Reception Channel Without Feedback

Abstract

Consider a time slotted communication channel shared by K active users and a single receiver. It is assumed that the receiver has the ability of the multiple-packet reception (MPR) to correctly receive at most γ (1 ≤ γ < K) simultaneously transmitted packets. Each user accesses the channel following a specific periodical binary sequence, called the protocol sequence, and transmits a packet within a channel slot if and only if the sequence value is equal to one. The fluctuation in throughput is incurred by inevitable random relative shifts among the users due to the lack of feedback. A set of protocol sequences is said to be throughput-invariant (TI) if it can be employed to produce invariant throughput for any relative shifts, i.e., maximize the worst-case throughput. It was shown in the literature that the TI property without considering MPR (i.e., γ = 1) can be achieved by using shift-invariant (SI) sequences, whose generalized Hamming cross-correlation is independent of relative shifts. This paper investigates TI sequences for MPR; results obtained include achievable throughput value, a lower bound on the sequence period, an optimal construction of TI sequences that achieves the lower bound on the sequence period, and intrinsic structure of TI sequences. In addition, we present a practical packet decoding mechanism for TI sequences that incorporates packet header, forward error-correcting code, and advanced physical layer blind signal separation techniques.Collision channel without feedback, protocol sequences, multiple-packet reception, throughput. I. INTRODUCTIONThe idea of using protocol sequences to define deterministic multiaccess protocols for a collision channel without feedback was proposed by Massey and Mathys in [1], and recently has attracted many research revisits [2]-[7] for different design criteria and applications. Compared with time division multiple access (TDMA), ALOHA and carrier sense multiple access (CSMA), protocol sequences do not require stringent synchronization, channel monitoring, backoff algorithm and packet retransmissions. Such a simplicity is particularly desirable in ad hoc networks and sensor networks, in which well-coordinated transmissions and time synchronization may be difficult to achieve due to user mobility, time-varying propagation delays and energy constraints.Moreover, in contrast to the random and contention based schemes, protocol sequences in [2]- [7] can respectively provide a positive short-term throughput guarantee with probability one in the worst case.Previous studies on multiaccess protocols have traditionally assumed a collision channel model of single-packet reception (SPR), in which a packet is received correctly only if it is not involved in a collision, i.e., does not overlap with another. However, the assumption of SPR becomes more and more unsuitable in practice, due to recent advances at reception techniques of the physical (PHY) layer, such as antenna arrays, CDMA technique and beamforming algorithms, which can be employed to ensure that the receive...

Adaptive uplink scheduling model for WiMAX network using evolutionary computing model

“…Now let's compute weight for each subscriber using (9). Employ MOGA to solve (8). The MOGA is composed of following phases such us Selection, Crossover, and Mutation.…”

“…In [8] presented a channel access mechanisms among subscriber using time slotted mechanism. Here, set of channel is shared among subscriber and each subscriber provides a dedicated slot time to transmit the packet.…”

DV-Hop Localization With Protocol Sequence Based Access

“…Thus a simple medium access method is desirable, which requires neither rigid time synchronization nor frequent channel sensing. Protocol sequences, as deterministic coding sequences for accessing a collision channel without feedback, can be a good choice [25]. Using protocol sequence based medium access method, it is not necessary for the transmitters to synchronize with each other.…”

“…Protocol sequences are originally proposed to achieve zeroerror capacity of a collision channel without feedback [25], [26]. Several types of protocol sequences have been constructed over these years, such as wobbling sequences [27], shift-invariant sequences [28], [29] and Chinese Remainder Theorem (CRT) sequences [30], [31].…”

New CRT sequence sets for a collision channel without feedback

“…Such simplicity is particularly desirable in wireless sensor networks (WSNs) and vehicular ad hoc networks (VANETs), where well-coordinated transmission and time synchronization may be difficult to achieve due to user mobility, time-varying propagation delays or energy constraints. The natural interest of protocol sequence based schemes, the guaranteed performance metrics, such as worst-case delay or minimum throughput, have been commonly considered in previous studies on protocol sequences [2,3,4,5,6,7,8,9,10,11,12]. In addition, some further performance metrics, such as average group/individual delay or average throughput, have been investigated in [4,11,12], and related approaches for sequence allocation can be found in [6,7,8,9].…”