On code design for simultaneous energy and information transfer

Abstract

Abstract-We consider the problem of binary code design for simultaneous energy and information transfer where the receiver completely relies on the received signal for fulfilling its real-time power requirements. The receiver, in this scenario, would need a certain amount of energy (derived from the received signal) within a sliding time window for its continuous operation. In order to meet this energy requirement at the receiver, the transmitter should use only those codewords which carry sufficient energy. In this paper, we assume that the transmitter uses on-off keying where bit one corresponds to transmission of a high energy signal. The transmitter uses only those codewords which have at least d ones in a sliding window of W = d + 1 bits. We show that with this constraint, the noiseless code capacity is achieved by sequences generated from a finite state Markov machine. We also investigate achievable rates when such constrained codes are used on noisy communication channels. Although a few of these results are well known for run-length limited codes used for data storage, they do not seem to appear in literature in the form presented here.

Constant subblock composition codes for simultaneous energy and information transfer

“…This threshold may be chosen to satisfy the received power constraint. Such a characterization would generalize the results in [8] which considered on-off keying and imposed a specific constraint that every sliding window of L bits should contain at least L − 1 ones.…”

“…Other possible energetic constraints on transmitted codewords include ensuring the runlength of lowenergy bearing symbols is always below a threshold [6], [7]. In [8], achievable rates are presented for the case where transmitter uses on-off keying and each codeword is constrained to have at least L − 1 ones in a sliding window of L bits.…”

Subblock-Constrained Codes for Real-Time Simultaneous Energy and Information Transfer

“…An alternate approach to meeting the sliding window constraint is to use type-1 (d, k) run-length limited (RLL) sequences [17]- [19], which require that the number of ones between successive zeros are at least d and at most k. In this regard, two different constraints are said to be equivalent if they induce the same set of constrained sequences. In general, it can be shown that the constraint of having at least d ones in a sliding window of length T = d + 1 is equivalent to the type-1 (d, ∞) RLL constraint [19]. On the other hand, it can also be shown that the constraint of having at least d ones in a sliding window of length T ≥ d + 2 is not equivalent to any type-1 RLL constraint.…”

“…This approach was adopted in [17] and [18], where the use of runlength codes was proposed. In [19], capacity bounds were presented under a sliding window energy constraint. Note that the sliding-window constraint is relatively stricter than the subblock-constraint which corresponds to the case where the windows are non-overlapping.…”

Nonlinear code design for joint energy and information transfer

“…The results show that constrained RLL codes are better suited for the receiver's energy utilization pattern compared to classical unconstrained ones. Binary code design for simultaneous en ergy and information transfer has been studied in [4] where achievable rates using constrained RLL codes on binary input noisy channels have been investigated. Most of the existing research in the area of joint energy and information transfer is on information theoretic approaches, specifically on capacity energy functions for different channels [2], on performance achievable with RLL codes [3] and achievable rates over some noisy binary channels using RLL codes [4].…”