CONTACT: Ari Dwi Hartanto, ari@ugm.ac.id Department of Mathematics, Universitas Gadjah Mada, Sleman, D.I. Yogyakarta 55281, Indonesia The article can be accessed here. https://doi.org/10.15642/mantik.2021.7.1.1-8 Binary Cyclic Pearson Codes Ari Dwi Hartanto1*, Al. Sutjijana2 1,2Department of Mathematics, Universitas Gadjah Mada, Yogyakarta, Indonesia Article history: Received Sep 2, 2019 Revised Feb 4, 2021 Accepted Mar 3, 2021 Kata Kunci: Jarak Pearson, Kode Pearson, Kode siklis Abstrak. Fenomena gain atau offset yang tidak terduga pada sistem komunikasi dan media penyimpan data modern seperti media penyimpanan berjenis optik (CD) dan memori non-volatile (flash) merupakan gangguan yang serius. Permasalahan ini dapat ditangani dengan mengaplikasikan jarak Pearson pada detektor error pada sistem tersebut karena jarak Pearson menawarkan kekebalan terhadap gain dan offset yang tidak menentu. Jarak ini hanya dapat digunakan pada suatu himpunan codewords tertentu, yaitu himpunan Pearson/kode Pearson. Salah satu contoh kode Pearson dapat ditemukan di kelas kode T-constrained. Dalam paper ini, diberikan kode 2-constrained biner dengan sifat siklis. Konstruksi kode ini diadopsi dari konstruksi pada kode siklis, akan tetapi kode yang dihasilkan tidak dapat dipandang sebagai kode siklik. Keywords: Pearson distance, Pearson code, Cyclic code Abstract. The phenomena of unknown gain or offset on communication systems and modern storage such as optical data storage and non-volatile memory (flash) becomes a serious problem. This problem can be handled by Pearson distance applied to the detector because it offers immunity to gain and offset mismatch. This distance can only be used for a specific set of codewords, called Pearson codes. An interesting example of Pearson code can be found in the T-constrained code class. In this paper, we present binary 2- constrained codes with the cyclic property. The construction of this code is adopted from cyclic codes, but it cannot be considered as cyclic codes How to cite: A. D. Hartanto and Al. Sutjijana, โBinary Cyclic Pearson Codesโ, J. Mat. Mantik, vol. 7, no. 1, pp. 1-8, May 2021. Jurnal Matematika MANTIK Vol. 7, No. 1, May 2021, pp. 1-8 ISSN: 2527-3159 (print) 2527-3167 (online) mailto:ari@ugm.ac.id https://doi.org/10.15642/mantik.2021.7.1.1-8 http://u.lipi.go.id/1458103791 Jurnal Matematika MANTIK Vol. 7, No. 1, May 2021, pp. 1-8 2 1. Introduction Based on [1] and [2], gain and/or offset mismatch often occur on modern storages and communication channels. In non-volatile memories, for instance: a flash memory, the data is stored in a floating gate. It can leak away from the floating gate and affects a shift of the offset. In optical disc media, the signal retrieved by the sensor depends on the dimensions of the written features and the quality of the light path. The quality of the light path usually occurs because of fingerprints and scratches on the disc surface. These lead to gain and offset mismatch of the retrieved signal. Regarding this problem, Weber et.al. [3] presented a system code which involves the Person distance. Pearson distance is resistant to gain and offset mismatch, so it can be an alternative to the Euclidean distance for improving the error performance of noisy channels with unknown gain and offset. Unfortunately, Pearson distance cannot be used for arbitrary sets of codewords, but it can only be used for a Pearson set/Pearson code, a set of codewords with special properties. Weber, Swart, and Immink [3] stated that one of the known Pearson code is ๐(๐, ๐). This code is a member of the T-constrained code class which consists of sequences in which each of T pre-determined reference symbols appears at least once ([1], [3], [4]). Let ๐ถ โ ๐๐ be a q-ary code of length n, where ๐ = {0,1, โฏ , ๐ โ 1} is the code alphabet of size ๐ โฅ 2. The alphabet symbols in codebook C will not be treated as elements of ๐๐, but as just integers. The reader should be careful that this situation will be different when we discuss linear codes in this paper. Weber, Swart, and Immink ([3], [5]) presented two coding procedures, i.e. fixed-to- fixed (FF) and variable-to-fixed (VF) length coding schemes which are special codes of ๐(๐, ๐). We present another special code of ๐(๐, ๐), that is Binary Cyclic Pearson Codes. We focus on how to construct the Pearson codes C in which the codewords have cyclic property, that is, if (๐0, ๐1, โฏ , ๐๐โ1) โ ๐ถ then (๐๐โ1, ๐0, ๐1, โฏ , ๐๐โ2) โ ๐ถ. Our idea is taking the similar way of cyclic code construction (see [6] and [7]) for constructing a cyclic Pearson code. Cyclic code is one of the most important classes of linear codes. The cyclic codes have a rich algebraic structure and can be efficiently implemented using simple shift registers [8]. Although the cyclic codes possess algebraic structure, we do not emphasize algebraic structure on the binary cyclic Pearson codes. We only concern on the set of codewords that have cyclic property and satisfy the axioms of Pearson code. We investigate whether it can be constructed and the simple encoding scheme with a generator matrix can be built in a similar way on the simple encoding scheme of cyclic codes. The rest of this paper is organized as follows. We start our presentation with a brief introduction to Pearson Distance, Pearson codes, and T-constrained codes in Section 2. In Section 3, we give a brief exposition of the cyclic codes, and then present binary cyclic Pearson codes. Finally, we draw some conclusions in Section 4. 2. Preliminaries We first introduce a necessary notation used in this paper. For simplicity, we use the shorthand notation ๐ผ๐ + ๐ฝ = (๐ผ๐ข1 + ๐ฝ, ๐ผ๐ข2 + ๐ฝ, โฏ , ๐ผ๐ข๐ + ๐ฝ) as described in [3]. The bold letter indicates a vector that can mean either a message word or a codeword. Suppose a codeword c is sent, and then a vector ๐ = ๐(๐ + ๐) + ๐ is received, where ๐, ๐ โ ๐ , ๐ > 0, and ๐ฃ = (๐ฃ1, โฏ , ๐ฃ๐) , ๐ฃ๐ โ ๐ . The real numbers a and b are called gain and offset, respectively, and the entries of vector ๐ฃ are noise sample from a zero-mean Gaussian distribution. The gain and offset will not affect sent codewords if we use Pearson distance detection ([9], [10]). The following is the Pearson distance that is a well-known concept in statistics. Let ๐ be a vector in ๐ ๐. Define: Ari Dwi Hartanto, Al. Sutjijana Binary Cyclic Pearson Codes 3 ๐ = 1 ๐ โ ๐ฅ๐ ๐ ๐=1 , and ๐๐ฅ 2 = โ(๐ฅ๐ โ ๐) 2 ๐ ๐=1 . The Pearson correlation coefficient of x and y is defined by ๐๐ฅ,๐ฆ = โ (๐ฅ๐ โ ๐) ๐ ๐=1 (๐ฆ๐ โ ๐) ๐๐ฅ ๐๐ฆ . Next, the Pearson distance is defined as follow: ๐ฟ(๐, ๐) = 1 โ ๐๐ฅ,๐ฆ . To know the bound of ๐ฟ(๐, ๐), we first note that โ1 โค ๐๐ฅ,๐ฆ โค 1. This implies that 0 โค ๐ฟ(๐, ๐) โค 2. By nearest neighbour decoding, a received vector will be decoded to the codeword closest to it, with respect to Pearson distance. If we have a received vector r, the minimum Pearson distance detector outputs the codeword: ๐๐ =๐๐๐ ๐๐๐ ๐๐๐ ๐โ๐ ๐ฟ(๐, ๐), where S is the codebook. We can observe that for all ๐ผ, ๐ฝ โ ๐ , ๐ผ > 0, we have ๐ ๐ฅ,๐ผ๐ฆ+๐ฝ = ๐๐ฅ,๐ฆ . The equation implies that ๐ฟ(๐, ๐ผ๐ + ๐ฝ) = ๐ฟ(๐, ๐). It means that the Pearson distance is invariant under translation and scale. As a result, the minimum Pearson distance detector is immune to gain and offset mismatch. However, this arises a weakness. We cannot use the minimum Pearson distance detector for arbitrary codebooks because it cannot distinguish between vector x and ๐ = ๐ผ๐ + ๐ฝ where ๐ผ, ๐ฝ โ ๐ , ๐ผ > 0, (๐ผ, ๐ฝ) โ (1,0), or mathematically, it can be written as ๐ฟ(๐, ๐) = ๐ฟ(๐, ๐) if ๐ = ๐ผ๐ + ๐ฝ, for all ๐ผ, ๐ฝ โ ๐ with ๐ผ > 0 and (๐ผ, ๐ฝ) โ (1,0). Because of this fact, our codebook C should has property that if ๐ โ ๐ถ then ๐ผ๐ + ๐ฝ โ ๐ถ for all ๐ผ, ๐ฝ โ ๐ with ๐ผ > 0 and (๐ผ, ๐ฝ) โ (1,0). Moreover, another property that has to be satisfied by codebook C is that vectors in the form of ๐ = (๐, ๐, โฏ , ๐) is not allowed in the codebook C since the vectors will lead to an undefined Pearson correlation coefficient. Definition 1. Let C be a nonempty subset of ๐๐. The set C is called Pearson code (or Pearson set) if it satisfies the following properties: a. If ๐ โ ๐ถ then ๐ผ๐ + ๐ฝ โ ๐ถ for all ๐ผ, ๐ฝ โ ๐ with ๐ผ > 0 and (๐ผ, ๐ฝ) โ (1,0). b. ๐ = (๐, ๐, โฏ , ๐) โ ๐ถ for all ๐ โ ๐ . To have an example of Pearson codes, we first give a description of T-constrained codes. Let ๐ be an integer with 1 โค ๐ < ๐ and reference symbols ๐1, โฏ , ๐๐ be element of ๐. A T-constrained code [1], denoted by ๐๐,๐(๐1, โฏ , ๐๐ ), consist of all q-ary codewords of length n, (๐ฅ1, โฏ , ๐ฅ๐ ), such that #{๐: ๐ฅ๐ = ๐} > 0 ๐๐๐ ๐๐๐โ ๐ โ {๐1, โฏ , ๐๐ }. Note that not all T-constrained codes are Pearson codes. For ๐ = 2, we can see that both 2- constrained code ๐๐,๐(0,1) and ๐๐,๐(0, ๐ โ 1) are Pearson codes, but for ๐ โฅ 5, ๐๐,๐(0,2) is not a Pearson code since it does not meet the first property of Pearson code. We now focus to discuss the specific case, that is the T-constrained code ๐๐,๐(0,1). This code is Pearson codes, and will be denoted by ๐(๐, ๐) as in [3]. Weber, Swart, and Immink [3] proposed easy coding procedures, i.e., fixed-to-fixed (FF) and variable-to-fixed (VF) length coding schemes, denoted by ๐๐น๐น(๐, ๐) and ๐๐๐น (๐, ๐), respectively. The simple Jurnal Matematika MANTIK Vol. 7, No. 1, May 2021, pp. 1-8 4 FF scheme is to fill the first ๐ โ 2 positions in the codeword c with information symbols and to fill the last two symbols for reference purpose, i.e., ๐๐โ1 = 0 and ๐๐ = 1. For VF schemes, it can be described as follows. a. Take ๐ โ 2 information from the q-ary source, and then set these as (๐1, ๐2, โฏ , ๐๐โ2). b. If there exists ๐, 1 โค ๐ โค ๐ โ 2, such that ๐๐ = 0, then choose ๐๐โ1 to be a new information symbol, otherwise set ๐๐โ1 = 0. c. If there exists ๐, 1 โค ๐ โค ๐ โ 1, such that ๐๐ = 1, then choose ๐๐ to be a new information symbol, otherwise set ๐๐ = 1. The resulted codewords from both schemes are in ๐(๐, ๐) since it contains at least one symbol 0 and at least one symbol 1. 3. Cyclic Pearson Codes In this section, we intend to construct cyclic Pearson codes by using similar ways as construction of cyclic codes. Let F be a finite field of order q, and ๐๐ (๐น) = {(๐ฅ1๐ฅ2 โฏ ๐ฅ๐ ) โฃ ๐ฅ๐ , โฏ , ๐ฅ๐ โ ๐น} be a vector space over F. A nonempty subset C of ๐๐(๐น) is called cyclic code if it is a subspace and every (๐1๐2 โฏ ๐๐โ1๐๐) โ ๐ถ implies (๐๐๐1๐2 โฏ ๐๐โ1) โ ๐ถ. Cyclic codes can be constructed by ring polynomial approach. Clearly, ๐๐(๐น) is an abelian group under vector addition, but it is not a ring since we have not had a multiplication between any two vectors yet. In order to have multiplication operation such that ๐๐ (๐น) is a ring, the easiest way is to associate vectors in ๐๐(๐น) with polynomials in ๐น[๐ฅ], that is, if ๐ = (๐0๐1 โฏ ๐๐โ1) โ ๐๐ (๐น), then let ๐(๐ฅ) = ๐0 + ๐1 + โฏ + ๐๐โ1๐ฅ ๐โ1. We select the polynomial ๐(๐ฅ) = ๐ฅ๐ โ 1 โ ๐น[๐ฅ] to have a quotient ring ๐น[๐ฅ]/โจ๐(๐ฅ)โฉ. For all ๐, ๐ โ ๐๐(๐น), let ๐(๐ฅ)๐(๐ฅ) = ๐ฃ(๐ฅ) where ๐ฃ(๐ฅ) is the polynomial of least degree in the equivalence class [๐(๐ฅ)๐(๐ฅ)] of ๐น[๐ฅ]/โจ๐(๐ฅ)โฉ. Note that ๐ฃ(๐ฅ) is the remainder polynomial when ๐(๐ฅ)๐(๐ฅ) is divided by ๐(๐ฅ), and it is a polynomial of degree at most ๐ โ 1 over F, which is associated with an element of ๐๐(๐น). In conclusion, now we have multiplication between any two vectors in ๐๐(๐น) which is defined by this way, and with the association between the vectors and polynomials, we can essentially think of ๐๐ (๐น) and ๐น[๐ฅ]/โจ๐(๐ฅ)โฉ interchangeable. Moreover, we can prove that ๐๐(๐น) is a ring. To have cyclic property of vectors, the choice of the polynomial ๐(๐ฅ) = ๐ฅ๐ โ 1 is most suitable. Multiplication a polynomial ๐ฃ(๐ฅ) in ๐น[๐ฅ]/โจ๐(๐ฅ)โฉ by x corresponds to a cyclic shift of v. This results in a fundamental theorem in cyclic codes presented as follows. A nonempty subset C of ๐๐ (๐น) is a cyclic code if only if the set of polynomials I associated with C is an ideal in the ring ๐น[๐ฅ]/โจ๐ฅ๐ โ 1โฉ. This property helps us in constructing cyclic codes. In fact, there is a unique monic polynomial of least degree that generates a nonzero ideal I of ๐น[๐ฅ]/โจ๐ฅ๐ โ 1โฉ, i.e., a monic polynomial divisor of ๐(๐ฅ) = ๐ฅ๐ โ 1. Thus, there is a 1 โ 1 correspondence between cyclic codes in ๐๐ (๐น) and monic polynomials ๐(๐ฅ) โ ๐น[๐ฅ] that divide ๐(๐ฅ). A monic polynomial ๐(๐ฅ) divisor of ๐(๐ฅ) = ๐ฅ๐ โ 1 over F having degree ๐ โ ๐ will become the generator for a cyclic code C of dimension k in ๐๐ (๐น). The encoder encodes the message polynomial ๐(๐ฅ) (of degree less than or equal to ๐ โ 1) to the codeword ๐(๐ฅ)๐(๐ฅ) โ ๐น[๐ฅ]/โจ๐(๐ฅ)โฉ. Thus, the generator matrix for cyclic code C is given in terms of ๐(๐ฅ) by ๐บ = [ ๐(๐ฅ) ๐ฅ๐(๐ฅ) โฎ ๐ฅ๐โ1๐(๐ฅ) ]. Note that G is a matrix of ๐ ร ๐ where the ๐๐กโ row of G, 2 โค ๐ โค ๐, is the ๐ โ 1 right shifts of the first row of G. Ari Dwi Hartanto, Al. Sutjijana Binary Cyclic Pearson Codes 5 We now turn our discussion to Pearson codes. For simplicity, sometimes we will write a vector in ๐๐(๐น) or in codes C in the form ๐0๐1 โฏ ๐๐ instead of (๐0, ๐1, โฏ , ๐๐). We note that the cyclic codes C are not Pearson codes since 00 โฏ 0 belongs to C. We observe some nonempty subsets of cyclic code C such that it is Pearson codes. In case our discussion is in Pearson code, we treat the information symbols of codewords as real numbers instead of elements of a finite field. In order to find a nonempty subset of cyclic codes C such that it is a Pearson code, clearly, we should eliminate the zero vector from C since it breaks the second axiom of the definition of Pearson codes. We should observe whether there exist other elements having form ๐๐ โฏ ๐ in C. Let us see a (7,4)-cyclic code over ๐2 generated by ๐(๐ฅ) = 1 + ๐ฅ + ๐ฅ 3. The generator matrix of code C is ๐บ = [1 + ๐ฅ + ๐ฅ3 ๐ฅ + ๐ฅ2 + ๐ฅ4 ๐ฅ2 + ๐ฅ3 + ๐ฅ5 ๐ฅ3 + ๐ฅ4 + ๐ฅ6 ] = [1 1 0 1 0 0 0 0 1 1 0 1 0 0 0 0 1 1 0 1 0 0 0 0 1 1 0 1 ]. The message ๐ = 1011 is encoded to be codeword ๐ = ๐๐บ = 1111111 โ ๐ถ. Such codeword must be omitted from C. It means that if our observation is in (๐, ๐)-cyclic codes, we have to make attention for messages from which codewords having form ๐๐ โฏ ๐. We note that such messages are the polynomials which are quotient of division โ(๐ฅ) = ๐ + ๐๐ฅ + โฏ + ๐๐ฅ๐โ1, where ๐ โ ๐น, by the generator polynomial ๐(๐ฅ) in ๐น[๐ฅ]/โจ๐ฅ๐ โ 1โฉ. Clearly, if c is a codeword of (๐, ๐)-cyclic code ๐ถ over finite field F, then ๐ผ๐ + (1๐น, 1๐น , โฏ , 1๐น) must be element of C, for all ๐ผ โ ๐. This does not meet the first axiom of the definition of Pearson codes. Now we go on a specific case, that is (๐, ๐)-cyclic code ๐ถ over finite field ๐2. In this case, we have a good result. We note that ๐ถ โ {00 โฏ 0,11 โฏ 1)} is a 2-constrained code ๐2,๐(0,1) if we treat the information symbols of codewords in C as real numbers. In conclusion, we obtain that the code ๐ = ๐ถ โ {00 โฏ 0,11 โฏ 1} is a Pearson code, and we call this code the binary cyclic Pearson codes. For a simple encoding scheme, we intend to use the generator matrix, but we face a problem when the message word is the zero vector. We should give a special treatment for this message word. First, we need to limit n to an even positive integer. We correspond the zero vector with the codeword 1010 โฏ 10. Since 1010 โฏ 10 is a codeword, 0101 โฏ 01 must be considered as a codeword. We correspond 0101 โฏ 01 with a message word ๐0๐1 โฏ ๐๐โ1 such that ๐0๐1 โฏ ๐๐โ1๐บ = 111 โฏ 1. Unfortunately, we cannot guarantee that such a message word will exist. In order to guarantee the existence of such a message word, the polynomial โ(๐ฅ) = 1 + ๐ฅ + โฏ + ๐ฅ๐โ1 must be divisible by the generator polynomial ๐(๐ฅ). By this condition, we have ๐0 + ๐1๐ฅ + โฏ + ๐๐โ1๐ฅ ๐โ1 is โ(๐ฅ)/๐(๐ฅ). Next, we should be careful if 1010 โฏ 10 belongs to (๐, ๐)-cyclic code C. It should not be allowed since we have corresponded 1010 โฏ 10 with message word 000 โฏ 0. Table 1. Some generator polynomials of binary cyclic Pearson codes n k Generator Polynomial 2 1 ๐(๐ฅ) = 1 + ๐ฅ 4 1 ๐(๐ฅ) = (1 + ๐ฅ) 3 6 5 ๐(๐ฅ) = 1 + ๐ฅ 3 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2) 1 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2)2 8 1 ๐(๐ฅ) = (1 + ๐ฅ)7 10 9 ๐(๐ฅ) = 1 + ๐ฅ 5 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2 + ๐ฅ 3 + ๐ฅ 4) 1 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2 + ๐ฅ 3 + ๐ฅ 4)2 Jurnal Matematika MANTIK Vol. 7, No. 1, May 2021, pp. 1-8 6 Table 1. Some generator polynomials of binary cyclic Pearson codes (continued) n k Generator Polynomial 12 9 ๐(๐ฅ) = (1 + ๐ฅ)3 7 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2) 5 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2)2 3 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2)3 1 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2)4 Based on the explanation above, not all (๐, ๐)-cyclic codes over ๐2 can be used for constructing a binary cyclic Pearson code. As summary, the following conditions must be held in order that (๐, ๐)-cyclic codes over ๐2 can be taken for constructing a binary cyclic Pearson code: a. n is even. b. The polynomial โ(๐ฅ) = 1 + ๐ฅ + โฏ + ๐ฅ๐โ1 is divisible by the generator polynomial ๐(๐ฅ). c. The polynomial 1 + ๐ฅ2 + ๐ฅ4 + โฏ + ๐ฅ๐โ2 is not divisible by the generator polynomial ๐(๐ฅ). By using MAGMA (Computational Algebra System) (see [11]), we observe all possibility of (๐, ๐)-cyclic codes over ๐2, for ๐ = 2,4, โฏ ,12, that meets three conditions above. Table 1 gives all generator polynomials of binary cyclic Pearson codes for ๐ = 2,4, โฏ ,12. Example 1. Consider ๐ = 6, ๐6(๐2), and ๐(๐ฅ) = ๐ฅ 6 โ 1. We take polynomial ๐(๐ฅ) = 1 + ๐ฅ as a generator of the binary cyclic Pearson code, so we have a generator matrix: ๐บ = [1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 ]. We divide 1 + ๐ฅ + ๐ฅ2 + ๐ฅ3 + ๐ฅ4 + ๐ฅ5 by ๐(๐ฅ), and we have 1 + ๐ฅ2 + ๐ฅ4 as a result. Then, the message words 00000 and 10101 are encoded to the codewords 101010 and 010101, respectively. For all ๐ โ ๐5(๐2) โ {00000,10101}, m is encoded to codeword ๐๐บ. Therefore, the binary cyclic Pearson code of length ๐ = 6 and with generator ๐(๐ฅ) = 1 + ๐ฅ is ๐ = {๐๐บ โฃ ๐ โ ๐5(๐2) โ {00000,10101}} โช ๐0, where ๐0 = {101010,010101}. 4. Conclusions A binary cyclic code of even length usually has a small Hamming distance. Some of the Hamming distances of cyclic codes can be seen on Table 2. A code with small distance can be said as a bad code because it can only detect and correct small errors. However, it does not mean that the code is always useless. As we explained above, an even length of code become one of the sufficient conditions for constructing a binary cyclic Pearson code. Therefore, some of cyclic codes of even length are needed for binary cyclic Pearson codes. In this paper we have investigated binary cyclic Pearson codes for ๐ = 2,4,6,8,10,12, and the result is that the binary cyclic Pearson codes exist for each of these n. We have not yet investigated codes of even length generally. Our conjecture is the binary cyclic Pearson codes exist for all even positive integer n. Ari Dwi Hartanto, Al. Sutjijana Binary Cyclic Pearson Codes 7 Table 2. Some generators of (๐, ๐, ๐)-cyclic codes and its compatibility for binary cyclic Pearson codes (BCPC) n k Generator Polynomial d Compatibility of generator for BCPC 2 1 ๐(๐ฅ) = 1 + ๐ฅ 2 yes 4 3 ๐(๐ฅ) = 1 + ๐ฅ 2 no 2 ๐(๐ฅ) = (1 + ๐ฅ)2 2 no 1 ๐(๐ฅ) = (1 + ๐ฅ)3 4 yes 6 5 ๐(๐ฅ) = 1 + ๐ฅ 2 yes 4 ๐(๐ฅ) = (1 + ๐ฅ)2 2 no 4 ๐(๐ฅ) = 1 + ๐ฅ + ๐ฅ 2 2 no 2 ๐(๐ฅ) = (1 + ๐ฅ + ๐ฅ 2)2 3 no 3 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2) 2 yes 2 ๐(๐ฅ) = (1 + ๐ฅ)2(1 + ๐ฅ + ๐ฅ 2) 4 no 1 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2)2 6 yes 8 7 ๐(๐ฅ) = (1 + ๐ฅ) 2 no 6 ๐(๐ฅ) = (1 + ๐ฅ)2 2 no 5 ๐(๐ฅ) = (1 + ๐ฅ)3 2 no 4 ๐(๐ฅ) = (1 + ๐ฅ)4 2 no 3 ๐(๐ฅ) = (1 + ๐ฅ)5 4 no 2 ๐(๐ฅ) = (1 + ๐ฅ)6 4 no 1 ๐(๐ฅ) = (1 + ๐ฅ)7 8 yes 10 9 ๐(๐ฅ) = 1 + ๐ฅ 2 yes 8 ๐(๐ฅ) = (1 + ๐ฅ)2 2 no 6 ๐(๐ฅ) = 1 + ๐ฅ + ๐ฅ 2 + ๐ฅ 3 + ๐ฅ 4 2 no 2 ๐(๐ฅ) = (1 + ๐ฅ + ๐ฅ 2 + ๐ฅ 3 + ๐ฅ 4)2 5 no 5 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2 + ๐ฅ 3 + ๐ฅ 4) 2 yes 4 ๐(๐ฅ) = (1 + ๐ฅ)2(1 + ๐ฅ + ๐ฅ 2 + ๐ฅ 3 + ๐ฅ 4) 4 no 1 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2 + ๐ฅ 3 + ๐ฅ 4)2 10 yes 12 11 ๐(๐ฅ) = 1 + ๐ฅ 2 no 10 ๐(๐ฅ) = (1 + ๐ฅ)2 2 no 9 ๐(๐ฅ) = (1 + ๐ฅ)3 2 yes 8 ๐(๐ฅ) = (1 + ๐ฅ)4 2 no 10 ๐(๐ฅ) = 1 + ๐ฅ + ๐ฅ 2 2 no 8 ๐(๐ฅ) = (1 + ๐ฅ + ๐ฅ 2)2 2 no 6 ๐(๐ฅ) = (1 + ๐ฅ + ๐ฅ 2)3 3 no 4 ๐(๐ฅ) = (1 + ๐ฅ + ๐ฅ 2)4 3 no 9 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2) 2 no 7 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2)2 2 no 5 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2)3 4 no 3 ๐(๐ฅ) = (1 + ๐ฅ)(1 + ๐ฅ + ๐ฅ 2)4 6 no 8 ๐(๐ฅ) = (1 + ๐ฅ)2(1 + ๐ฅ + ๐ฅ 2) 2 no 6 ๐(๐ฅ) = (1 + ๐ฅ)2(1 + ๐ฅ + ๐ฅ 2)2 2 no Jurnal Matematika MANTIK Vol. 7, No. 1, May 2021, pp. 1-8 8 Table 2. Some generators of (๐, ๐, ๐)-cyclic codes and its compatibility for binary cyclic Pearson codes (BCPC) (continued) n k Generator Polynomial d Compatibility of generator for BCPC 12 4 ๐(๐ฅ) = (1 + ๐ฅ)2(1 + ๐ฅ + ๐ฅ 2)3 4 no 2 ๐(๐ฅ) = (1 + ๐ฅ)2(1 + ๐ฅ + ๐ฅ 2)4 6 no 7 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2) 4 yes 5 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2)2 4 yes 3 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2)3 4 yes 1 ๐(๐ฅ) = (1 + ๐ฅ)3(1 + ๐ฅ + ๐ฅ 2)4 12 yes Acknowledgement We thanks to Jos Weber from Delft University of Technology (TU Delft) for the discussion and his papers shared with us. References [1] K. A. S. Immink and J. H. Weber, โMinimum pearson distance detection for multilevel channels with gain and/or offset mismatch,โ IEEE Trans. Inf. Theory, vol. 60, no. 10, pp. 5966โ5974, 2014, doi: 10.1109/TIT.2014.2342744. [2] F. Sala, K. A. S. Immink, and L. Dolecek, โError Control Schemes for Modern Flash Memories,โ IEEE Consum. Electron., vol. 4, no. 1, pp. 66โ73, 2015. [3] J. H. Weber, K. A. S. Immink, and S. 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